GIS CAD Interoperability

ArcGIS Data Creation: Freezed-Dried Features

2011-12-16T11:02:00.001-08:00

Let’s go MATRIX: DUCKY-roll; look dish!

Establishing a vocabulary of shortcut commands and workflows is essential to any effective production environment. Nowhere is it more true than when establishing audible calls coaching basketball where opportunities come and go quickly. Each word, phrase and number is packed full of meaning.

If I have an assembly of multiple GIS features that I want to add to a drawing all at once in ArcGIS for AutoCAD, for example when adding a fire hydrant assembly to a water system that is composed of separate Hydrant, Valve and Service Line features, I can create one version of that combination that I am using over and over again as a block. I can fill in many of the attributes for each feature and then freeze them into an AutoCAD block. Likewise I may have explicit variations of that combination of features that could warrant their own separate block collection made of the same features, but with a different geometric configuration or set of attributes. I can then insert those standard AutoCAD blocks containing my assembly of ArcGIS attributed features. Once exploded using the AutoCAD EXPLODE command each assembly then falls onto the appropriate layers with the right attributes and graphic properties effectively creating the appropriate features.

Once I create my block assembly I can drag an instance of that block onto one of my custom AutoCAD tool palettes. From then on I can quickly place lots of ArcGIS data all at one time that is readily accessible, tidy and organized.

AutoCAD Tip: I could set the properties of the tool on the tool palette to EXPLODE the block automatically. I can also have it prompt me to rotate the assembly. However, using the Explode option on the tool palette also scrubs the entities of their ArcGIS attribute data creating brand new, rather than pre-populated attributes. If instead I use the AutoCAD command EXPLODE to explode the block after inserting it then the ArcGIS feature attributes are retained. I mention this because if you want to pre-populate the features with data, you want to be mindful that the explode option on the tool palette, although convenient is removing any pre-populated ArcGIS attributes. By using the standard AutoCAD EXPLODE command after placing the block, my pre-populated attributes are retained.

…We’re RED on the make, back BLUE to WALMART!

ArcGIS Data in AutoCAD with Tool Palettes

2011-12-08T15:31:00.000-08:00

Thanksgiving has come and gone this year and I got the chance to use my favorite tool. Anyone who ever builds any tool or product should study this device and you will realize that until you can achieve the level of simplicity, function and delight delivered by your own tool you still have work to do on your design.

Ever since Esri defined the standard method of storing ArcGIS data directly inside standard AutoCAD .DWG files I’ve been easily creating ArcGIS data using ArcGIS for AutoCAD. Once I define a feature class (usually based on a specific AutoCAD layer) I use plain AutoCAD to create ArcGIS data inside AutoCAD. I can also add GIS attributes to any of the entities I create.

For different types of maps I generally have a different set of features I am creating. A great way to create short cuts for the types of features I create and always being sure I get those entities on the right layer with the right color etc. is to utilize standard AutoCAD tool pallets. Inside any AutoCAD session I can create an AutoCAD tool palette that has different types of features I might want to create.

The way standard tool pallets work in AutoCAD is perfect for this type of thing. Once I create a tool palette I just copy a representative object from my map and paste it onto the tool pallet. I then rename the object to keep track of what it is I am going to be placing. The cut-n-paste operation keeps track of how the representative object was normally placed and its graphic properties. Therefore, if I use the tool palette to place a new feature it will automatically call the necessary AutoCAD tool, and place the entity on the right layer with the right color etc. into my drawing.

I created my own ArcGIS for AutoCAD a tool palette group and I have different tool palettes for different maps that I edit. Depending on the type of project I am working on I’ll simply switch between the different palettes to place the right type of object according to my GIS and CAD standards.

AutoCAD Tool palettes are fun and productive for generating ArcGIS data in AutoCAD.

I will say that I was only able to process one apple using the device since everyone else in the kitchen was fighting over it. We ended up making one more pie than we needed because everyone wanted their turn!

When Engineers Cook

2011-10-07T14:47:00.000-07:00

We’ve had foreign exchange students staying with us off and on for the last couple of years and one of the things we like to do is cook foods they like. We ask them what their favorite meal is if they go to a restaurant back home. Once we work out the translation of what it is, more than once (four times so far), we are sternly warned by the student with the phrase, “you can’t make it!” Strange, they use exactly those words. They don’t mean that I personally do not have the culinary skills to make it, but rather in a categorical sense no one, and especially not me, can make it! “Really, you can’t make that… how then is it ever made?”, I ask. “You cannot do it, it is very hard”, is usually the answer.

As you might imagine rather than taking it as a warning, I take it as a challenge and off to the Google to find the recipe. Sometimes this requires more translation, which is actually really fun. So far I am 3 for 4 on "impossible" dishes, but I haven’t given up on that one recipe. I have ideas for fixing it.

If you are cooking up a map in AutoCAD you may have noticed there is a new quick access basemap you can choose from the Esri Maps button in the ArcGIS for AutoCAD 250 you already have. This new map is designed to have a more subtle and ambient cartographic feel to it. There is nothing to download its just a new map on ArcGIS Online that showed up. You automatically get it since the ArcGIS for AutoCAD design team thought you might like it.

Bon appetit

Bonus Sushi Making Tip: If you are using cream cheese in a sushi roll, like a Philadelphia Roll, freeze the cream cheese block first and then it is easy to cut into strips and handle. It thaws nicely and quickly afterwards.

Finding My Center… Board

2011-08-31T10:51:00.000-07:00

I took my humble sailboat out sailing with a friend the other day. When we got to the beach I realized the centerboard was hanging in the garage 20 minutes away. I apologized to my friend and then jokingly took the auxiliary plastic paddle and slid it into the centerboard slot. My adventuresome friend shot me a let’s-try-it look. So we used the little plastic paddle as a centerboard. We had a spirited sail and that modest paddle held its own. While underway water was gushing out of the space normally filled with the proper centerboard. I then began falling behind on the bailing. A small crack in the deck at my feet meant that the hull was also filling up with water in addition to the cockpit. We had to cut the afternoon short to avoid breaking the paddle and risking a long swim. Something was going to give way, and or we were going to end up sailing the boat underwater.

The paddle did work in one sense, but then again it didn’t provide us with the same productivity or performance we should have enjoyed, and indirectly lead to more slowing by contributing to a combination of issues that could have sunk us. The paddle was capable, flexible, but not the right equipment for the job. The right equipment, my boat’s centerboard, was on the shelf in the garage and afforded me no benefit where I was... at the beach.

It is becoming increasingly clear to me that I need access to the right tools for different working environments in the place I need them. In terms of GIS I need at different times to be working inside CAD, or in a web app, and other times collaborating with CAD, desktop and mobile colleagues with the same information, each in our own way at the same time.

I like how ArcGIS Server multi-user feature services allow me to edit geodatabases using just the free viewer on ArcGIS.com, or ArcMap, or with my I-phone, or soon with ArcGIS for AutoCAD all using the same online services. The ArcGIS system concept fueled by ArcGIS Server services make good sense and is simplifying how I work.

There is a new ArcGIS.com capability that allows me to upload file-based data into online web maps to share and edit. It spins-up my uploaded file-based data into a GIS service in the cloud that I can share and edit.

1. Bring the centerboard
2. Patch the hole in the deck
3. Check out the new ArcGIS.com file-based data upload capability <here>
4. Get ready for smooth sailing ahead

Wild Cards and Conventions

2011-07-18T12:00:00.000-07:00

It was great to see all of those in attendance at the Esri 2011 user’s conference this past week in San Diego. Thanks for all of your encouragement about this blog. It was great to hear from many of you regarding how you are using ArcGIS for AutoCAD and improving how information is exchanged in CAD and GIS departments within your organizations. It was exciting to share some of the work we’ve been doing. I enjoyed meeting with many of you as during the technical sessions, and while answering your questions throughout the week.

Can you use wild cards within the ArcGIS for AutoCAD feature-class-definition query-filter to simplify the description of entities that qualify for a feature class in ArcGIS for AutoCAD?

ArcGIS feature classes stored inside AutoCAD .DWG files are defined by a query that is used to filter the contents of the drawing. Features are not created as objects defined as one feature class or another, but rather qualify for membership based on if their CAD entity properties match the feature class definition. The query statement syntax used by ArcGIS for AutoCAD is based on the named object selection filter functionality of AutoCAD. Most of the same capabilities are available to you when you define a feature class definition query in ArcGIS for AutoCAD. This includes the use of wild cards (*). Some things you should avoid when defining a feature class in ArcGIS for AutoCAD would be conditional operators. Even though they will work when using ArcGIS for AutoCAD, ArcGIS Desktop will not be able to read them when it opens the drawing file. Therefore I avoid using conditional operators within my drawings (these include: NOT, AND, OR, XOR…).

Just because I can specify a very specific and complex query to define a feature class within ArcGIS for AutoCAD doesn’t mean I should. Whenever reasonable I like to make a simple correlation between my AutoCAD layers and their GIS equivalents. Sometimes I have to be a little more exacting when I am conforming to an existing CAD Standard, in which case the filtering queries I create to define a feature class are necessarily as complex as they need to be to define the GIS feature classes. However, when I have a choice I define a single AutoCAD layer to describe a GIS layer of the same or similar name.

To use wild cards in the filter query to define a feature class of Curbs as any AutoCAD layer that has the word Curb in it, I can modify the value in the grid for the layer field to include the value *Curb* as shown in the graphic below. This will define an ArcGIS feature class of Curbs for any layer in my drawing that has the string Curb in the name.

Documenting ArcGIS for AutoCAD Schema

2011-02-24T09:57:00.000-08:00

Coaches make choices from many options to direct their team over the course of a game and a season. It is always wise to teach and implement the fundamentals, but there also comes a time when we have to commit to an individual team strategy that will focus on our strengths and optimize what we’ve got that works. It’s about that time in the season that we need to decide what is working, what is fixable and what we need to let go. We need to execute a realistic vision to ensure we present a solid game plan going into tournament time. It’s a good time to formally articulate those regular-season-proven options as a baseline template for moving forward.

Here is an AutoLisp command that will write out a text file report of the ArcGIS for AutoCAD schema that is included in my current AutoCAD drawing session. This is a great way for me to document on paper my GIS and CAD interoperability standards. The report includes the Esri attribute schema definitions, the coordinate system and the filtering criterion that defines how my AutoCAD standards are interpreted as feature classes by ArcGIS.

Download it, unzip it, then load and run the command in ArcGIS for AutoCAD. It will create a text file that has the same name as the drawing in the same location with an .MSCr file extension.

This command is one of several available in the Esri CAD code gallery that can be used to extend the functionality of ArcGIS for AutoCAD.

For tournament time, I’m thinking we start out MATRIX and if they pack-it-in, we go THRILLER, if we’re not converting then we attack the COZY ZONE and focus on skip-pass ball reversals, and DEATH STAR opportunities. :)

The Butterfly Effect and Geoprocessing CAD

2011-02-17T11:30:00.000-08:00

I sucessfully helped a neighbor secure their wireless router while sitting at my dining room table (remember their wireless network was unsecured). The same day my internet service provider sent me a message saying they had to reset my internet access password. This resulted in a 1 hour phone call and complete reconfiguration of my home network. The next day my neighbor’s daughter was at my house finishing a school project on my computer because their internet service was cut off. Walking next door to the neighbors, I was obligated to determine if they had the same internet provider and needed to undergo the same reconfiguration that I had just completed on my own home network. They had a different internet provider and it was unlikely the same situation. However, I had just modified settings on their router so… what did I do?!… checking… isolating the modem…resetting… wait… where is the phone plug? “No it’s not the plug… see the plug is protected over here way behind the cabinet and nobody ever… wait its loose hey does that green DSL light mean anything!?” “Ok, sorry that was weird … thanks, it’s all working now.”

One small change upstream can make a huge amount of difference downstream. When I create a Model Builder Model in ArcGIS that takes as input one or more feature classes from a CAD file I could expose that single feature class as a property of the tool so that I can rerun my model on any CAD feature class, but I don’t. Instead, and especially if I am using more than one feature class from the same CAD file, such as building polygon from selected points and lines within a CAD file, I add the SELECT DATA tool at the beginning of my model and anticipate the CAD feature classes that I want to use in my model. Instead of having to browse to multiple CAD feature classes within the same CAD file, my resulting tool can have a single input of the entire CAD file as a data set folder. I know what I want to get out of the CAD file so I hard-code those feature classes as parameters of the SELECT DATA tool in my model. I then expose the CAD file input to the SELECT DATA tool so that now I have a single CAD file input to my simple or complex model. I might be doing all kinds of interesting post-processing to analyze or migrate data from a given CAD file. I now can combine multiple models and sub-models to process everything I might be doing to a given CAD file.

This weekend was finally time to fix that leaky shower in the upstairs bathroom. Can’t be that hard to fix, right? Let’s cut to the chase. Yes you really do need two special tools (despite what the guy in the plumbing isle at the hardware store says) a seat-wrench, which is a metal bar with a square tapered end to insert into the square shaped seat-nut opening inside the pipe inside the wall. You also need what amounts to a big socket wrench that has an open end so you can place it over the valve stem body and remove the valve from the pipe in the wall. You could use a pair of channel locks and barely grab some of the exposed hex nut without destroying the surrounding tile, but it might cause you to make an extra trip to the hardware store if you crush the soft brass valve as you install it and nothing will thread into it (DON’T ASK!, buy the stupid socket wrench thing.) Once you finish all is well, but you will have to replace the flapper in the toilet of the adjacent bathroom, that has been working fine until right now since the rubber has become so hard that in will no longer seal. Before the shower project: the toilet is fine; now not just a leak, but a total toilet tank sealing failure. The flapper rubber has gone from functioning, to too hard to make any seal. Back to the hardware store (4th trip of the day).

Now I just have to wait by the phone for a call from the neighbor to answer the question of why their stopped-up kitchen sink is NOT my fault!

Attributed Parcels in AutoCAD

2011-02-01T14:57:00.000-08:00

My wife is a piano teacher and has long wanted to have a grand piano in our home. She teaches piano from the faithful upright piano she practiced on when she was in elementary school. We could never seem to get it together to make her grand piano materialize with our budget and other priorities. Then last week my wife got a call from a friend of an ex-student, and yesterday some men dropped off a grand piano in our living room. We didn’t do anything. For the next few years we are giving it a “good home”. That was easy.

To create attributed parcels in AutoCAD I draw closed polylines on an AutoCAD layer that I have named PARCELS. Since I have downloaded and installed ArcGIS for AutoCAD, all I need to do to store the parcel identification number (PIN) on my parcels is to go to the feature class management tab on the ArcGIS for AutoCAD ribbon and define a feature class that identifies the AutoCAD layer named PARCELS as the distinguishing filtering criteria for my parcels and then add a STRING attribute definition to the schema called PIN.

ArcGIS for AutoCAD and ArcGIS now understand that my AutoCAD drawing contains attributed PARCEL features. These parcel features are comprised of any closed polylines, with or without curves on the PARCELS layer. By simply using the AutoCAD entity property panel I can edit the parcel identification number (PIN) for any of the parcels. To draw a new parcel I just continue to draw parcels like I always do with closed polylines on the AutoCAD layer called PARCELS. The Parcel Identification number (PIN) is now just a property of the entity that I can modify with the entity property panel.

Since ArcGIS desktop also understands this attributed feature class inside the drawing I don’t have to do anything else to make my parcels accessible to an ArcGIS user. I’m done. When the ArcGIS user opens my AutoCAD drawing they see my PARCELS feature class and can use it directly in their map or in any geoprocessing operation that can use attributed polygons.

I'm wondering if anyone has a 16ft sailboat on a trailer, that just needs a "good home" for a couple years?

GeoDesign Summit 2011

2011-01-11T11:51:00.000-08:00

The second GeoDesign Summit hosted by Esri and the University of Redlands has come and gone. The event was characterized by the generous exchange of ideas. These ideas came from smart people with different gifts and strengths. Ideas with real value, and some ideas were even strictly about values. Some of the benefit of the exchange was thinking through bad ideas, battling through conflicting ideas, and celebrating good ideas. Some ideas are at a global scale, some are ideas about technology trends, some ideas are about strategies of implementation. Some ideas were about human values, ethics and happiness, others about databases, chaos theory, butterfly theory and web services.

At the summit I learned about the quantifiable benefits and efficiencies of urban living and was almost convinced that living in a city was my ethical duty, if it were not for my strong preference. I’d rather live in a high-tech tree stump than live in a big city, regardless of how well designed efficient or carbon neutral. I like the idea of everyone else living in a city so I can live on a wild life preserve at the beach, but I am not sure that would be “right” either. I’d rather live next to an idyllic lake; I’d rather live in the lake.

Definitions of Geodesign were offered and some were repeated, but they are themselves more ideas. Putting one idea together with another creates yet another new idea. New ideas are often different ways to ask the question that leads to a new method of solving a new problem. It may look like the old problem but it is not, and neither is the old method useful to solve it.

Quantum advancements of entertainment and movie making and viewing; and distribution of media; and movable type were all used as examples of new modalities that prompt the asking of new questions and methods to solve those questions. New technology enables new ways to look at problems and in-turn new ways to ask questions. Often solutions create new problems/opportunities in the process.

I spent the week thinking about Civil Design and BIM. I see that in the search for a universal digital data model to encapsulate all of reality for geospatial and/or other information systems, the more flexible and inclusive the data structures I employ to abstract the data for digital storage, the more complex the database becomes until I get to the point where the data model is as complex as physical reality.

The argument was repeated at the summit that since the world is 3D, design software should be 3D. I agree, design software should be 3D. I have nothing against the 3rd, 4th or 5Th dimensions. True, the world is 3D, however; when I think about it, the world is also made of molecules and atoms and weird little sub-particles, but that is not necessarily a compelling reason to store quarks in a database.

…Which then leads to the logical conclusion that reality itself is a better more inclusive and flexible data storage container than a digital database. This seems like a dead-end idea unless I consider that accessing and retrieving data from physical reality may just be a viable option in many applications?

With fast connected communication, sensors, radio tagging, scanning and measurement found in Radar, LiDAR, , and other forms of imaging, the digital database model may not be the end-all information repository we thought it had to be. Using digital communication, search, interpretation and pattern recognition focused upon physical reality may in the end be a more practical means to store, retrieve and manage data for many forms of geospatial information. Transactions to and from reality itself may be an easier way to realize many of the hopes and ideas expressed about Geodesign.

Sensors and machine-control will replace SQL. An “ idea”, good or bad? …maybe not an original idea …come to the summit next year and let’s talk about it!

My Favorite Maps and Christmas Lists

2010-12-10T09:18:00.000-08:00

I am starting to consider my Christmas list, and it’s time to do some searching. Like many I am hunting around for ideas for others and looking for bargains. I am considering a Kindle for myself because of its limited- function free 3G wireless web browser and that book reading thing it does.

What’s in your ArcGIS for AutoCAD favorite’s maps list? In mine I have: Soils Maps, NGS Survey Control. Real-Time Traffic and Weather Maps, etc… Where did I find them? That is probably a more interesting question. Go to http://www.arcgis.com/. Search for content that contains Map Services. When I find a Web Map that might have a useful Map Service. I drill down into the table of contents of the webmap using the ArcGIS.com online map viewer and copy the shortcut to the included URL. I can drill into the table of contents and find a layer that is based on a map service and take a look at the details of the layer.

One of the items on the description page of an included map service detail will be the “supported interfaces”. If I right-click on the REST option and select the [copy shortcut] option I will get a URL to the rest endpoint. Some Web Maps containing map services might also include the server URL right on the description page without having to right click on the REST link.

For example the NGS Survey Control Map service has this URL shortcut associated with the REST link:
http://maps1.arcgisonline.com/ArcGIS/rest/services/NGS_
Survey_Control_Points/MapServer/0?f=json&pretty=true

This is the complete address to the NGS survey control points map contained in this web map. To use this information in ArcGIS for AutoCAD I have to simplify the URL. I only need the link to the map server. The address from above needs to be edited to become simply: http://maps1.arcgisonline.com/ArcGIS/services/

Notice the URL is simplified and the REST directory reference is removed to use the URL in ArcGIS for AutoCAD. I will be asked in ArcGIS for AutoCAD to select from a list of all the maps that may be on this same server.

Access to other ArcGIS Online maps can be used in ArcGIS for AutoCAD entering this URL into the Server URL parameter of the ArcGIS for AutoCAD Add Maps function :

http://server.arcgisonline.com/ArcGIS/services/

This USGS site includes lots of interesting map services including real-time weather (nhss_weat): http://rmgsc.cr.usgs.gov/ArcGIS/services/

There are many more free maps available from Esri and other sources than the ones you see in the Esri Maps dialog box.

Try all of these URL’s by entering these strings into the Server URL option of the ArcGIS for AutoCAD Add Map Service dialog to see what interesting maps there are to use in ArcGIS for AutoCAD.

One more thing worth mentioning about the NGS control point map mentioned above is that when you use the IDENTIFY tool to get information about the control point in ArcGIS for AutoCAD one of the attributes of the control point is a web page URL to the current “data sheet” of that control point in addition to the other attributes of the control point.

Happy maps and Merry Christmas.

Creating GIS Lines and Polygons in AutoCAD

2010-12-07T13:50:00.000-08:00

Here in Southern California basketball fans have different choices when it comes to NBA basketball. The Lakers have certainly had their share of success. The LA Clippers, although they play in the same arena as the Lakers, tend to measure their success in smaller increments. This last week the Lakers and Clippers where both represented on the highlight reels. Blake Griffin represented the Clippers for his wild-man dunking exploits and the Lakers for their four game losing streak. There is something beautiful about the straight forward approach to a game that suggests the best way to score sometimes is to just jump high and go full force at the goal.

If I want to create ArcGIS data using AutoCAD in a way that will ensure the best experience of interoperating with ArcGIS I use ArcGIS for AutoCAD. It allows me to enter GIS data in AutoCAD for use in ArcGIS, which is often one of the first things I need to do when working on a new project.

In AutoCAD I could use different techniques such as object data or external links to databases to create GIS data, but it is still not usable in ArcGIS. With premium add-on products like AutoCAD Map 3D I could directly edit Esri Shapefiles. With the new ArcGIS FDO connector from Autodesk (32 bit, ArcGIS 9.3.1, requires subscription license of AutoCAD Map 3D, requires ArcGIS license) I can even directly edit older geodatabases. This FDO connector for ArcGIS 9.3.1 is an interesting alternative to FDO Shapefiles, or FDO ArcSDE support, when I need to edit ArcGIS data rather than just prepare GIS data.

However, by far the simplest cost effective means to prepare attributed data within AutoCAD for future use in ArcGIS is to use the free ArcGIS for AutoCAD plug-in and use the simple resulting .DWG files. Take a look at the overview video found here to learn more.

The free ArcGIS for AutoCAD application is designed to help me create GIS using just plain AutoCAD. It also provides the means to connect me to Esri GIS maps and Imagery that I can use for reference and for context, not because it is interesting, or because it is pretty, but because it is useful. I can outfit AutoCAD users outside my organization to create GIS data for me that my ArcGIS system can directly use. I can also share my ArcGIS maps with them. With a copy of my data schema in the form of an AutoCAD template file, and with the free application, AutoCAD users outside my organization can be creating ArcGIS data with my schema within AutoCAD files for me, without buying anything new.

If anybody wants some cheap tickets to a Clipper’s game December 22nd, 2010 at Staples center against the Houston Rockets email me! (or leave a comment) Seriously I have like 100 tickets (3rd level mid-court and some first level endzone seats).

Free CAD Editing in DraftSight and AutoCAD WS

2010-11-04T11:14:00.000-07:00

Free time! When was the last time I had any? I am thinking there is a difference between rest, vacation and free time. When I was in elementary school free time was absolute and timeless, there was nothing before it or after it in my mind, which is why I think elementary aged kids are so devastated when free time ends and something else begins, it never occurred to them that it would or should, end.

Need a free way to create and edit AutoCAD .DWG files? Even better than the light-function AutoCAD WS in the cloud from Autodesk (which is pretty cool in its own right) is this interesting and free DraftSight software from Dassault Systems, the makers of CATIA and SolidWorks. DraftSight seems to be a full function free .DWG editor for my desktop.

I used both of these software to make changes to AutoCAD files that contained GIS content exported from my ArcGIS and created with my ArcGIS for AutoCAD.

I was able to upload .DWG files I created from ArcMap to AutoCADWS.com. I populated the .DWG file with new entities that were understood as GIS features, using only the free AutoCADWS.com web editor interface. I could not modify or add GIS attributes of features according to the Esri ArcGIS for AutoCAD method of attributing entities, but all my geometric edits were recognized as GIS features edits when I brought the drawing back into ArcMap, and ArcGIS for AutoCAD. I found the editing tools in the web interface of AutoCAD WS allowed me to do some real work, especially on existing AutoCAD drawings. I did find I was using more manual drafting techniques like swinging arcs and finding intersections with the included snapping tools. To get the drawing back on my desktop I download it back to my desktop from the cloud using the download button on the DRAWINGS tab of AutoCADWS.com.

In the case of Dassault’s DraftSight, I just downloaded and used the software to edit my .DWG drawings. My drawings contained feature class schema defined from ArcGIS for AutoCAD and from the ArcGIS EXPORT TO CAD tool. All my geometry edits were valid since the software edits .DWG format drawings.

Drawings created and used in ArcGIS for AutoCAD, survived the round-trip cloud editing, just as they do for any valid editor of a .DWG file, including AutoCAD LT, Microstation, IntelliCAD or the new free DraftSight software from Dassault. Editing GIS attributes and viewing map services is not possible while the drawing is in the cloud on AutoCADWS.com, or in .DWG editors without ArcGIS for AutoCAD software (Only available from Esri for AutoCAD) loaded, but the drawings remain intact when they come back to ArcGIS for AutoCAD, or when used in ArcGIS desktop. Any geometry edits made in the cloud, or other .DWG editing software will work just fine as geometric GIS edits in the drawing.

If I want to see the Esri map services I enjoy in ArcGIS for AutoCAD when my drawing is up in the cloud on AutoCADWS.com, or in Dassault’s DraftSight, all I have to do is disconnect the Esri map service map using the disconnect map function in ArcGIS for AutoCAD. The snap shot of my map is included as an AutoCAD raster reference backdrop positioned correctly when I upload it and view it in the cloud or, when I use the .DWG file on my desktop with DraftSight. I can only see one map at a time in AutoCAD WS, or DraftSight since transparency is not supported on layers in either software at this time. I can choose to leave the Esri map service references (which are custom objects) in the drawing and they will be seen as blank proxy objects in AutoCAD WS and DraftSight. Once the drawing is viewed back in ArcGIS for AutoCAD they will be quickened back into Esri Map Services, and I will see the dynamic Esri map again.

Enjoy your free time.

Map Service Transparency Tool

2010-10-22T11:30:00.000-07:00

Confessions of a non-texter. As a habit I don’t text, I just don’t. Nor do I tweet, twit or chirp. I lost my smart phone and my new phone doesn’t have a keyboard, which makes the thought of texting even less desirable (since it takes me forever to peck out a message T9 or otherwise). I was the guy 5 years ago that mocked texting as a teenager’s technology fascination akin to rediscovering Tetris, or more accurately the telegraph. Why would anyone pay extra for it? I did not anticipate that the secrecy factor was the primary benefit. Mobile phone conversations could be overheard by others. The secret text message is like passing notes and no one else can tell who it is from. It is also valuable as an emotionless voice mail. Ahh… instant email, now I get it.

My current solution, I scribble down a message, I take a picture of my notepad and send that as a photo message. My texting productivity has improved 500%! I have not discovered fire, as my carpool partner would be quick to point out, but I guarantee my wife and kids would much rather see my handwritten notes and drawings sent as a photo than the emotionless font in a text message.

Here is a sample AutoLISP routine that helps me quickly see a composite stack of map services I’ve added to a drawing at the same time by controlling the transparency of their AutoCAD layers. In AutoCAD 2011 I can change the transparency property of any layer including those that contain map services by using the standard layer controls of AutoCAD. This AutoLISP routine gives me a quick way to apply a transparency percentage directly to all the map service layers at one time without having to specify each one. It is also a useful example of how to automate workflows that involve map services using AutoLISP. Find this and other useful sample tools in the code gallery of the Esri CAD Integration resource center.

Is it easier to text, or scribble on a note pad and send pictures …while driving?!

Quickly Toggle Map Service Visibility

2010-10-14T10:28:00.001-07:00

I had a rather strange outing the other day. I drove to the local coast to have a beach fire, roast marshmallows, enjoy the full moon, the stars and the sound of the ocean waves. The evening was as you can image; beautiful. There were a number of young people with us and near us. And like many teenagers they have been stricken with a debilitating condition: this ailment results in the loss of the use of their right hands, poor hearing, and limited attention span from cell phone addiction. They find it difficult to rise from the seated position in a low chair, dare they lose sight of the screen or lose physical contact with the device that might result in missing a vibration fix from an incoming text message.

The luminous intensity of the bonfire in front of this one teen was significantly interfering with his vision in contrast to the phone display, resulting in facial contortions and pained squinting to discover that his friend had texted that he is bored and just wanted him to know. Without taking his eyes off his phone he texts a media message of the fire in front of him to his friend, who like he, can now experience the event on his 1 inch screen. I’m wondering if the digital version of life somehow seems more real or important to them within the device when compared to the full spectrum 3D experience they might enjoy should they but lift their gaze up 5 degrees… Strange world we are creating.

Well sometime we just need to turn it off; turn it all off. Although map services are extremely valuable for both context and reference, sometimes I just want to edit my drawing completely undistracted. Here is a simple lisp routine I can add to a toolbar in AutoCAD that will toggle the visibility of all the Esri map services in my drawing on, or off with a single click. When added to a toolbar button, this tool gives me a one click On/Off. Find this tool and other useful sample tools at the Esri CAD integration resource center code sharing gallery… and consider submitting your own.

Life, it is just like the Wii, ...only real.

ArcGIS for AutoCAD NETLOAD

2010-10-08T09:59:00.000-07:00

If you follow this BLOG let me warn you that baseketball season is starting up again and that means lots of running for the team, and more tedious basketball/GIS metephors are in your future! Speaking of getting started here is a little info for getting started with ArcGIS for AutoCAD 250 that is different than past versions...

To make installation greatly simplified for all version of AutoCAD, the new ArcGIS for AutoCAD 250 must be NETLOAD-ed each time you run ArcGIS for AutoCAD. If like me you always want to load ArcGIS for AutoCAD you can use one of many ways in AutoCAD to autoload a .DLL like ArcGISForAutoCAD.dll.

I invoke a script from my desktop ICON. AutoCAD just needs to find both my script and the .DLL. You can update your AutoCAD SUPPORT path or modify the START IN directory or like me do both.

Here is the content of the script that I use to AutoLoad ArcGIS for AutoCAD:

_RIBBON
netload
"ArcGISForAutoCAD.dll"

The included image is a picture of my modified desktop short cut.

Note: Be sure to include a carriage return after the last line.

ArcGIS for AutoCAD 250 and Other New Stuff

2010-10-06T18:19:00.000-07:00

Got a new car (used, but new to me). New phone (cheap, but with just the features I need).

…ArcGIS for AutoCAD 250 is something brand new. It supports 64 bit and 32 bit AutoCAD versions 2010 and 2011 (likely 2012 when it ships). I really like using it with its new ribbon interface, better map image quality and performance. It supports connecting to more kinds of servers with certain forms of authentification and now supports ArcGIS Server fast maps. ArcGIS for AutoCAD 250 has a clever new set of selection tools that have been added. Performance when editing large amounts of attribute information is also greatly improved.

I like the quick access to Esri Maps on the Ribbon. I also like that I get to use AutoCAD 2011 and its clever entity cloning feature (Add Selected) that is especially useful when creating new features. However, my favorite AutoCAD 2011 enhancement, layer transparency, enables me to create composite maps in ArcGIS for AutoCAD from multiple map service sources, and create watermark style images that won't overpower the AutoCAD entities I’m working with while still allowing me to see and use my GIS maps.

You can download it today here.

Carlson Software and Esri Interoperability

2010-09-24T12:16:00.000-07:00

The leaves are changing color; kids are all back at school and autumn has fallen. Then again, at my house it’s going to be 90 degrees this weekend.

Here’s something else that’s hot. Here is a webinar presentation from the City of Waterbury, CT working with Carlson Software to improve their Survey/CAD/GIS workflows.

The AutoCAD drawings that I create using SurvCE use the same GIS data structures as ArcGIS for AutoCAD and ArcGIS Desktop so I can use them directly without conversion or further processing.

Hidden CAD Properties In ArcMap

2010-08-11T14:09:00.000-07:00

Someone dropped their cell phone into a standing body of water… again. She claims it was on the blink anyway… off to the cell phone store for the “free” phone upgrade with 2 year contract etc… but turns out the week before I was browsing on the cell provider's web site and found a clever new way to save money with an upgrade of the family’s existing phone plan to the “plus plan” that has the *same service and that is cheaper (bad sign). Apparently one of the plus’s I get with the new plan is that I don’t get any more phone “upgrades”.

ArcGIS reads the graphic properties of CAD entities (color, layer, line style etc…) as feature attributes. In recent versions of ArcMap the more esoteric CAD graphic properties are hidden from view. The reason is that many of those graphic properties such as the extrusion vector have limited application in GIS and people were doing more work to hide them. In the same spirit of simplicity feature classes defined in ArcGIS for AutoCAD don’t include these hidden lesser-used graphic properties (I can’t unhide them because they are not there), the thought being with this type of CAD feature class I intend to work with my attributes exclusively as GIS content. One exception to this I can think of is working with text or block attributes as a feature class of say MANHOLES or VALVES and I am interested in the rotation angle of the features.

That rotation angle information is accessible to me in the CAD file, but not on the named feature class MANHOLES I have set up in ArcGIS for AutoCAD. Because feature class definitions in ArcGIS for AutoCAD files are really filtered queries or “database views” of the CAD file, all of the graphic property information is included on the default unfiltered feature class views of ANNOTATION, POINT, POLYGON, POLYLINE and MULTIPATCH. I can join the two together to get all the attributes I need.

If I turn on the visibility of the HANDLE property of my MANHOLE feature class and the HANDLE field of the POINT feature class I can use ArcMap to JOIN the two layers together. I join the two layers based on the entity HANDLE field. I change the field visibility in ArcMap by using the FIELD tab of the properties panel that I invoke from right-clicking the layer in the table of contents. In this way my MANHOLE feature classes from ArcGIS for AutoCAD can display any of the CAD graphic properties supported by ArcMap including my rotation angle value.

Sometimes less is more and only because I don’t want too much. Sometimes (like when I need what is missing) less is just less. Simple = good; complex = bad is generally a good adage. Unless the aim is to confuse, like cell phone billing and credit card promotions, but I think that is a different issue all together. Good for them bad for me!

Flexible Feature Classes in ArcGIS for AutoCAD

2010-07-21T11:13:00.000-07:00

When coaching a basketball team I really enjoy encouraging the players and seeing them improve. Kids play sports for the exercise and to have fun... it is supposed to be fun. Sometimes I would also have them listen more closely and try harder, because lets face it I want to WIN! Getting the best out of the players means a balance between challenging them (yelling) and guiding them (more yelling; perhaps with a different tone). These goals, fun and excellence don't have to be mutually exclusive. Truth is the best teams do both, they work hard listen and have more fun when they win, or at least when they are playing up to their potential.

In ArcGIS for AutoCAD a feature class is defined by filtering the entities in the drawing. An entity can belong to more than one feature class. Because of this I can have a filtering query where a feature class called WATER LINES is defined as all linear entities on the WATER LATERAL, WATER MAIN, and WATER PIPE layers. Subsets of these same entities can have their own feature classes defined with filtering criteria based solely on each of the single AutoCAD layers and or other criterion. This way when I want to work with the different kinds of pipes separately, I can.

Not only can entities have duel membership in feature classes, but because descriptive attributes are attached to the entities themselves, the feature classes can have different sets of attributes for the same entity. This means that entities can also share the same attributes honored in different feature class schema without duplication. When you want to work with the pipes as a whole you can use the feature class that includes them all. All the pipes may have the attributes of MATERIAL and DIAMETER, but perhaps only the LATERALS prompt for a STREET ADDRESS.

I can have a feature class in ArcGIS for AutoCAD that is defined as all the UTILITIES that might include the WATER, SEWER, CABLE TV and TELEPHONE. In most applications you would never want to mix the WATER and the SEWER… unless your goal was to perhaps avoid them all as in the case when you want to dig a new trench.

NICE SHOT!, ... now GET BACK AND PLAY SOME DEFENSE!

Georeferencing Inside AutoCAD

2010-04-05T09:03:00.000-07:00

The basketball team that I help coach has been going through a four year transformation from underdog to the team to beat in our league. On the national homeschool scene where small, big and medium sized fish from all over the country get together for a national championship tournament we had a different problem. Algorithmically generated rating systems had elevated our team's national ranking to a condition of being overrated going into the national tournament.

CAD files that are drawn in a local coordinate system (say origin 0,0 etc.) can be adjusted in ArcGIS by means of the proper coordinate transformation defined in a “world file” [.WLD]. Once created the coordinates in the drawing are adjusted by ArcGIS accordingly to move, scale and rotate the data into their correct real-world coordinates when the drawing is used in GIS. ArcGIS automatically applies the coordinate modifications to the drawing in ArcGIS from then on when the [.WLD] file containing the offset information is present. What if the tables are turned? What if I want to bring the world to me, like I can do with ArcGIS for AutoCAD? What then, since the coordinate actually stored in my CAD file are not tied to the earth in anyway?

Best practice is to fix the AutoCAD file using AutoCAD’s MOVE, ROTATE and SCALE commands. You’ll need to know where things are supposed to fit and if you want it to fit exactly you’ll have to know exactly where it is supposed to go. If someone has already defined the offset information in a .WLD file, then use that. Fixing the coordinates in the CAD file itself is always a better solution than relying on world file if you are an AutoCAD user. The world file is really just a crutch to force things to work., and especially useful if I don’t have AutoCAD. However, once the coordinates are adjusted in the AutoCAD file itself, there is no need for the .WLD file anymore, and I must delete it to avoid re-applying the now unnecessary transformation.

Here is a sample AutoLISP Routine I can use to automate the process of applying the information in an ESRI World file to reposition a drawing’s coordinates. This is a solution for AutoCAD users and I must have AutoCAD to run it. I use the AutoCAD LOAD command to load the AutoLISP routine and then run the tool by typing in its command name, “ApplyWorldFile” at the AutoCAD command prompt. If I decide I don’t want to keep the transformation I can use the AutoCAD UNDO command or simply not save the file. Just to be safe I may also want to save the drawing under a different name.

WARNING: This AutoLISP routine will move scale and rotate your drawing according to the instructions contained in a valid .WLD file. Use at your own risk. That is to say unlike the world file when used in ArcGIS that repositions the position of the file in memory while in ArcGIS this routine will actually change the AutoCAD file’s entities. It is only useful if you know and trust the information in the .WLD file.

Alas the day of reckoning has come and gone and our team finished a respectable 23rd in the nation in 2010. Looking forward to my daughter’s last year next year we have one last chance in our quest for a top 10 finish. Summer basketball camp starts June 1st!

GIS BIM Ideas

2010-02-05T15:52:00.000-08:00

I was working on a water distribution project the other day involving a critical system. The extension supply line had failed and the loss of service was dramatically impacting the normal workflow. (The sprayer hose on the faucet of our kitchen sink broke.)

I have a pretty low expectation and opinion of the plumbing products industry when it comes to interoperability. When approaching a plumbing project my normal strategy is to buy three different sizes of each of the different major types of fittings, compression, fine and coarse threaded, and then return the ones I don’t use. This usually ensures that I only have to make two rather than several trips back and forth to the hardware store.

Jaded and cynical I made my way to the local hardware store looking to replace the hose endeavoring not to have to replace the faucet which we all know by domino effect can cause you to repaint the exterior of the house! …oh honey, the new faucet makes the sink look ugly, and that countertop, on those old cabinets that don’t match the floor, or the trim in the dining room, which would clash with the style of the sofa, and the entry way light fixtures, which shows the scratches in the front door which needs to match the exterior paint scheme!

At the hardware store I started looking first at a couple of brand name replacements, and then a couple generic hoses. None looked like they’d fit mine. Mine had a weird end on it. Then I saw the larger packaged hose labeled universal faucet hose replacement kit, it promised to fit all major brands including my faucet brand. Looking at the impressive collection of fittings jingling around inside the package I was compelled to purchase it with my faith in standards swelling. I opened the bullet proof packaging which always manages to leave a few cuts on my hands from the jagged razor sharp plastic that results from carving the product from the package. Spilling the contents of the universal adapter on the floor I removed the defective spray hose from the faucet and started matching up both ends to my universal adapter fittings. No, no, no… kind-of… if I attach this one, and no, ...not that one… this and that, …wait no, if I turn this around …then the male…no I need the female of that… no.

At the recent GeoDesign summit I attended an idea lab where the group discussed, among other things, the prospects and benefits of improved integration between GIS and BIM. The group tended to migrate towards two sometimes competing, sometimes cooperative suggested solutions. One idea focused on defining and creating information exchange standards through Web Services and the other solution was to embrace the defining of data-encoding, naming, exchange and storage standards. Both aproaches seemed to have some promising prospects.

The web services approach allows the data to be stored in whatever means is convenient, but puts the onus on some software service to extract answers to specific requests of useful data from those convenient data stores.

The data standards approach allows the information to be organized into a common pond, or more specifically discrete cups, buckets, bowls and the alike by defining what and where things should be named, stored and found. If everyone uses the same system of sorting, filing and stacking then different systems could leverage the same data.

Alas, plumbing standards had failed me even after some 5000 years of working on the problem. Defeated I went out and bought a new faucet. Interestingly enough the new faucet that I bought had a clever new-fangled quick connect hose feature that made installation a snap, it was easy. It made my installation experience quite simple and I appreciated the design effort that went into the solution. However, my universal hose kit adapters would not have worked with this new hose either.

Lesson learned: Apparently before you run out and buy a universal adapter you need to know which universe we’re talking about.

Joining Data Tables to CAD Layers

2010-01-13T14:01:00.001-08:00

An electronic football game for Christmas; the stadium, the acition of the players, the electronic rumble; very cool (circa 1975). I hope everyone had a great Christmas this year. CAD and GIS interoperability at its worst can be a lot like vintage electronic football, put them together on the same field, add some agitation … sometimes you win, and sometimes you lose.

I hope sometimes this information helps us be a little more strategic than that! Because CAD is just another GIS data source in ArcGIS, I can join CAD to external database tables with a simple right-click. Microstation files that came from Geographics or MGE can also be rich with external attribution in a joined table. This is information I can hook back up in ArcGIS. You may also be working with AutoCAD files that have associated external databases tables linked to the AutoCAD entity handle or other properties that are easily connected. Or you may anticipate the CAD data will be connected to data in the future and you are including just a unique number or code of some asset that you'll want to identify and coorelate to existing databases.

ArcGIS You can join tables to any GIS layer including CAD feature classes. I join tables based on some key field that both CAD feature class and the external file have in common. In the case of Microstation that key field is likely going to be the MSLink value. In the case of AutoCAD files it is typically the Entity Handle or perhaps a unique value in a block attribute. I right click on the CAD layer in the table of contents in ArcMap and I pick the option: Joins and Relates> Join…

With the table joined to the CAD features I use the information in the external table to drive my map symbology, as the basis for selection, calculations and analysis or to enhance the data content I am migrating into my geodatabase.

I baked my first apple pie yesterday with my own apple peeler-slicing machine I got for Christmas.

Carrying GIS Data in AutoCAD

2009-12-17T13:37:00.000-08:00

Just watched a movie, the Carriers, one of those hmmm-never-heard-of-that-movie-before –wonder-if-it-is-any-good?, type of movies. Can't say that I'd recomend it. Often watching this kind of movie is like when your spouse hands you something from the refrigerator and asks you… “honey, could you smell this?” You are seldom ever glad you did!

This story didn’t have a compelling setting, or interesting conflict or really anything except an oppressive global plague where everyone dies except for two of the minor characters. Not sure if the movie was designed to help promote euthanasia or swine flu vaccination, but it is probably not going to win any feel good movie of the year awards.

Act 1: Most everyone is already dead, and the sick are going to die.

Act 2: Most of the survivors get sick.

Act 3: The sick people die and the two people that remain are lonely and still might die. …roll credits.

I my mind a good story has a conflict that needs to get solved, some interesting solutions to that conflict that is inspiring, or clever, and then a happy ending or at least an important lesson learned.

Today’s story:

The conflict: I want to create some GIS data with AutoCAD. Do I need to create Shapefiles, or buy more software... what will I ever do? (insert perilous music here…pass the popcorn).

The solution: download the free ArcGIS for AutoCAD and use it to create GIS data using plain AutoCAD.

The happing ending: The AutoCAD file you create will contain GIS data that ArcGIS can directly use.

Lessons learned: Use AutoCAD to carry GIS data rather than deadly infectious diseases.

FDO, Shapefiles and ArcGIS

2009-11-06T15:19:00.000-08:00

My daughter’s high school basketball team had the opportunity to play at the Staples Center this week in Los Angeles for their first pre-season basketball game of the year. It was a great experience for the girls. Our point guard even buried an NBA length three-pointer during the game! Our opponents were a team from Lancaster that we will play twice more during the year. Although the court was the same size as some of the college venues we play at, the seating capacity was a lot larger. The additional markings on the floor, the wide key and distant 3 point line, also told the story of how others who play on this court are playing at a much higher level.

For existing Autodesk Map 3D users the ability to read and write Shapefiles is a useful feature, likewise the access to simple feature layers stored in ArcSDE using FDO. You can even add to that working with WMS map services served up by ArcGIS Server that are similar to the Map Service capability of ArcGIS for AutoCAD, but without the ability to identify features.

If you use Civil 3D the included Autodesk Map 3D functionality gives you access to Shapefiles and ArcSDE simple features you can use in the process of design.

If the main reason I use Autodesk Map 3D is to read and write Shapefiles to work with ArcGIS than I'd say there is an easier way. ArcGIS for AutoCAD working with plain AutoCAD files is superior to using tools that read and write Shapefiles, simply because the support in ArcGIS of the resultant AutoCAD files is better. Namely the attributed feature classes inside AutoCAD files that are created and read by ArcGIS for AutoCAD and ArcGIS desktop are self-contained in the AutoCAD file and can include curves and annotation. The simple features in Shapefiles don’t support annotation or curves. Software that reads and writes Shapefiles in AutoCAD adds another level of cost and complexity; ArcGIS for AutoCAD is free and works on pure AutoCAD entities within a single AutoCAD file. But if I have Civil 3D it’s not a bad way to go.

When considering the Autodesk Map 3D FDO connector for editing however, I must be concerned not only about the lack of curve and annotation support, but also in the fact that the GIS data in ArcSDE may be participating in a geodatabase, for which the ArcSDE API used by FDO has no awareness. The blind simple features edits of FDO made directly to ArcSDE can and will ignore important data integrity rules established in a geodatabase, so be careful.

The girls are now 1-0 in the pre-season.

ArcGIS-Ready AutoCAD Template Files

2009-10-22T15:55:00.000-07:00

I need to compel my children to do things that are good for them, and good for the family, but they may not always see it that way. Whether it’s eating healthy or getting to sleep, or not watching TV all day, even simple things can become a battle. Routines and schedules can do a lot to help set a foundation for success. Other times I just need to set up circumstances where they can’t fail.

AutoCAD template files are most often used to pre-define layers and symbology to support my CAD standards. Using a template file with mapping specification for drawings feature layer definitions allows me to support both a CAD standard and a GIS schema at the same time. AutoCAD drawings files that contain mapping specification for drawings feature class definitions can subsequently be edited by any software that can edit the .DWG file. Because the feature layer definitions of ArcGIS for AutoCAD are stored as standard graphic and non-graphic entities in the DWG file, any software that can edit a 2007-2009 .DWG file can be a viable ArcGIS data creation tool.

Without ArcGIS for AutoCAD I would not have a way to edit any feature attributes that might also be defined as part of the feature layer. My edits would be limited to creating feature class geometry. But I can create feature class geometry in AutoCAD LT, plain AutoCAD without ArcGIS for AutoCAD loaded, or even Microstation (although I've not tired it, I would expect versions of IntelliCAD would work too). All of these can create entities in a DWG file that are recognized by ArcGIS, and ArcGIS for AutoCAD. By simply following my existing CAD standards with feature class enhanced template files, I will be populating ArcGIS feature layers no matter what tool I use. The key to my success is that the feature layer definitions are stored as filtering information on the contents of the file, what ever that ends up being.

Here is a short video of creating an AutoCAD template file that contains ArcGIS feature layer definitions...

Creating Multiple CAD files from ArcGIS

2009-10-13T11:26:00.000-07:00

When coaching sports, executing a play can be rather complex with interrelated situational options involving both rules-based and opportunistic options that are very dynamic. Once you have diagramed the play and the team has really learned it, the result is all the players doing the right thing when the coach gives a single command. When the team doesn’t learn the play in a game there is no time to explain how each player needs to respond specifically to a given situation. Which results in the meaningless rants of coaches: “Move your feet!”, “Reverse it!”, “See the floor!”, “GO!” which taken at face value are not very instructional… but they make coaches sound wise, or at the very least make the coaches feel like they are contributing.

GIS data sets can be huge, CAD files can be big. Sometimes big gets to be too big. ArcGIS is designed to accommodate large datasets by managing data from the source in ways that it doesn’t have to load all the data into memory while also employing database science to manage large queries and analysis. The drafting environments of AutoCAD and Microstation employ high-end graphics technology that promotes fast drawing of large datasets, but was never designed for large scale data management. Traditionally the CAD solution is to break up files into vertical or horizontal tiles that can be combined together by reference or to be viewed individually. Within the context of mapping these might be vertical tiles where different drawings are stacked on top of one another based on their content discipline. For example a layer of electrical distribution data, another drawing which contains the parcel and street data, another for water, sewer etc…

Another method of tiling is by geographic zone. Horizontal tiles include all of the data in each tile, but multiple tiles are used to cover a geographic area. This form of tiling also supports the idea of pages in a map book, or districts, zones or other arbitrary or gridded system of breaking up the map. These grids may be to distribute responsibility, or they may be based on, ownership or other geographic boundaries. When moving CAD data from a gridded tiling system into ArcGIS tools like APPEND and MERGE are common tools to create a seamless map.

To recreate the tiling systems of CAD, the EXPORT TO CAD tool can be used to generate multiple files from a single GIS data set. The key is to include a field in the data sets feature attribute table called DocPath. Within this field you can populate each feature’s DocPath value to control which Microstation or AutoCAD file the data should be exported to.

First you will create a polygon grid that represents the geographic boundaries of what would be each CAD file. Then populate each polygon with a value in a field called DocPath that represents each CAD file name. Then I use that grid to perform a spatial join or an overlay function and maybe the CALCULATE tool to include the CAD DocPath on each feature I intend to export. I then invoke the EXPORT TO CAD tool. Be sure to leave the Ignore Paths In Tables option of the EXPORT TO CAD tool unchecked because this is what this option is for.

Then MOVE YOUR FEET! :)

ArcGIS for AutoCAD Query Tool

2009-10-09T11:15:00.000-07:00

I spent last weekend installing a laminate floor in a small room off my kitchen. This was the third phase of my flooring project that has been spread out over a few years. The first being the living room, then the kitchen. In the previous two phases I pretty much did all the work myself. For this room I enjoyed the service of my capable daughter to assist me. Not only was the effort more efficient, it was also more enjoyable because I didn’t have to spend the weekend alone in the back room, doing a thousand deep knee bends… Can someone say Advil?

In a previous post I described a way to select entities based on a simple query of ArcGIS for AutoCAD feature attributes. It was really more of a simple AutoLISP code sample than a tool…

A talented colleague has created another sample query tool that I do use as my query tool for the mapping specification for drawings data used by ArcGIS for AutoCAD. If you maintain attributes in AutoCAD using the mapping specification for drawings I recomend that you download this as your query tool.

REVIT to ArcGIS

2009-10-02T11:21:00.001-07:00

The downside of online shopping. I needed an odd sized bolt made of brass for my old sailboat and it was nowhere to be found in the local hardware stores. Easy enough to pay a little extra for shipping to save me the trouble of driving all over town. I quickly found a couple different vendors and chose the one that looked like they were really doing e-business and pushed the button and waited for the confirmation. Two phone calls and three, “ we shipped it yesterday emails”, still no bolt after over a month. Sometimes grabbing hold of the real thing and walking it to the register is the best way to go. Until e-business and boat hardware inventory systems are more interoperable… I’m off to the hardware and marine supply stores to find, and grab a 8 ½ inch quarter-twenty brass carriage bolt and matching wing nut that I can put in a bag, buy, take home and fix to my boat. …but wait I see another confirmation in my inbox.

Although, far from being an integrated system, I still have a need to get data from REVIT into ArcGIS. Here is the path I used last time I did this to create features in ArcGIS. You may find other paths to get there. Working with one DXF file exported from REVIT. The resultant AutoCAD file contained 3D entities that ArcGIS doesn’t support (Polymeshes). However, exploding them with the AutoCAD EXPLODE command did create 3D Faces that are supported by ArcGIS. From REVIT I can also export data to a 3D Studio file (.3DS). I could have used ArcGIS at this point to bring the entire 3DS file in as single 3D symbol in ArcScene or ArcGlobe, but I wanted to get the individual building parts as separate multipatch features. I imported the .3DS file into plain AutoCAD, which generates 3D face entities directly, the type of 3D CAD entities ArcGIS does support as multipatch features. The resultant AutoCAD file could then be used in ArcGIS.

Yet another option if you are confronted with AutoCAD SOLIDS entities exported from REVIT is to use the AutoCAD 3DSOUT command to export the resultant AutoCAD SOLIDS out of AutoCAD into a .3DS file and then import them back in. The result again is 3DFace entities. (If your version of AutoCAD doesn't have the 3DSOUT command, check here.)

To make the drawings even more usable I created separate muiltipatch feature classes using ArcGIS for AutoCAD for each different building part that were easily destinquished based on their AutoCAD Layer. Now when I add the data from either of the two AutoCAD files in ArcGIS I get 3D multipatch feature layers that correspond to the different building parts. I can also use the existing CAD georeferencing tools of ArcMap to position my building in geographic space, and migrate the data into a geodatabase if needed.

Autodesk Object Data Converter

2009-09-28T08:34:00.000-07:00

I just bought a sunfish sailboat. Arguably the most successful sailboat design, with over 500,000 made. This sailboat is easy to sail and has pretty good performance. My boat is one of the old ones, 1965. Several design changes over the decades have improved the design's performance. Better, rudder and centerboard shapes and materials, and a kick-up rudder feature that allows for easier beach launching are some of the more notable improvements. Its upstart cousin the Laser is faster… but not as easy to sail. Although both are touted as being “car-toppable”, both are still a little more than I want to manage by myself from my garage to the water and back without a trailer.

I have been on a quest to design a sailboat, toy, machine or thing that is fast, comfortable, simple to sail, and easy to transport by one person. I’m currently working on my 11th significant prototype concept of such a boat… I bought the sunfish because I’d actually like to sail something now!

I have some drawings that were created by someone else in Autodesk Map 3D that I need to use in ArcGIS. I have Autodesk Map 3D and could use it to convert the Object Data to Shapefiles to make the drawings more usable by ArcGIS, but a colleague has just put together an Autodesk Map 3D converter that I can run in conjunction with Autodesk Map 3D that keeps the data inside the AutoCAD file. This tool generates attributed AutoCAD drawings according to the mapping specification for drawings that I can understand and that are readily usable by ArcGIS for AutoCAD and ArcGIS desktop.

I had to spend some time in my garage retrofitting a little utility trailer to accommodate the sunfish, next weekend I will be sailing!

Getting In Shape

2009-09-25T11:30:00.001-07:00

As a volunteer assistant high school basketball coach and former athlete myself, I understand the value of off season training. Getting in game-ready shape is much different than just general physical fitness. I work out at the gym sporadically. Yesterday I played a game of basketball with the high-schoolers and quickly realized that my two mile jog twice a week was not going to take me many times up and down the floor at the pace they were running!

During the season, even as a coach I still get anxious before each game. I get transported back to the feeling I had as a player… Do I have my shoes and uniform …my sweatbands? Do I feel ready to run and jump,... ya know my knee is kind of stiff? Then I realize the only physical exertion that will be required of me is to occasionally leap off the bench and shout at the referees… respectfully of course!

Working with ESRI Shapefiles as an intermediate exchange between AutoCAD and ArcGIS is one way to move data back and forth between ArcGIS and AutoCAD. It requires that you have a way to read and write Shapefile within AutoCAD. You may have an existing routine that you jog through to make this happen.

I think people are just now coming to realize that with ESRI’s mapping specification for drawings the AutoCAD .DWG file itself is a better intermediate file for sharing data between AutoCAD and ArcGIS. It handles attribution on Points, Lines, Polygons, 3D features and Annotation. Annotation, curves and splines are supported where as in Shapefiles they are not. With the free ArcGIS for AutoCAD application there is also no need to buy any software to support the exchange of data between ArcGIS and AutoCAD.

I'm learning to sit down, relax and enjoy the game.

Selecting by Attributes in ArcGIS for AutoCAD

2009-08-03T08:51:00.000-07:00

It probably isn’t too convincing from my blog picture, but I look just enough like NBA all-star Dirk Newitzki in-person that I am frequently mistaken for him in airports, hotels and restaurants. It’s a dubious honor to simply look like someone famous, since in the end everyone is disappointed when they learn I am just me.

At a food court in San Antonio I was unable to convince a 10 year old “fan” that I wasn’t Dirk, and he forced me to sign an autograph. I have posed for a number of photos with strangers, who didn’t care if I was him or not, they just wanted to say he/I was there in the picture.

My brother-from-another-mother is 6 inches taller and shoots better free throws than me. These are just a couple of the attributes that distinguish us one from another.

Here is an AutoLISP routine that selects features by feature-attribute values in ArcGIS for AutoCAD. It uses a combination of standard AutoLISP and the ArcGIS for AutoCAD AutoLISP API. It has a simple command line interface that allows me to click through the schema of feature classes in my drawing to build a simple equality-query for the selected feature class.
(ie This = That)

You can use this AutoLISP file, as is… if it works for you, or you can use it as an example of how to build your own query tool that could make more sophisticated comparisons.

The AutoLISP code snippet below is that part that does the work… Look here for the complete AutoLISP routine that includes the command line interface.…

;Select All The Entities In the Target FC
(esri_SelectFC TargetFC)
(setq ss (ssget "P"))

(setq NextEntity 0)
;Create New Empty Selection Set
(setq newSS (ssadd))
(setq SelectionCount 0)

;Check each entity in the selected set of features
(while (setq ent (ssname ss NextEntity))

;Use the ArcGIS for AutoCAD routine to get the MSD attribute values
(if (setq ValuePair (esri_GetAttribute ent TargetField))
(progn
(setq EntityValue (cdr ValuePair))

;Compare to this entity’s MSD Attribute Value to the Target Search
Value
(if (= SearchValue EntityValue)
(progn
(setq newSS (ssadd ent newSS))
(setq SelectionCount
(+
SelectionCount 1))
)
)

)
)
(setq NextEntity (+ NextEntity 1))
);End While Entities

;Set/Grip Selection Set
(setq ss (sssetfirst nil newSS))

ESRI User Conference 2009

2009-07-20T12:20:00.000-07:00

Walking out the back door of this year’s ESRI user conference the BMW/Oracle sailing team’s trimaran was prominently positioned to steal my gaze. An amazing display of engineering and design… wow. It really impressed me with its elegant lines and high tech equipment. Looking at it right in front of me, my mind struggled to understand how huge this boat really is. Rather than accept how big it was my mind tried to force me to see the crew on the trampolines and hoisted up working on the mast as Lilliputians (tiny people). The man suspended on a boson’s seat rocking in the wind on the top of that 150+ foot mast was normal sized! The people on the sailing team were tuning that machine to make it work for them. They were preparing to set out into the ocean to battle the wind, weather, waves and the competition. People design, build and endeavor to do some truly amazing things!

It was great to meet many of you in San Diego this year. You provided us with a wealth of feedback that will really make a difference in the direction and priorities of GIS and CAD interoperability development at ESRI. I hope that you also were able to use the information we shared to make a positive difference in your work. Spending a week with people like you and hearing what you accomplish and endeavor to create is an awesome thing to experience.

ArcGIS Server Maps in Microstation: Easy as Pie

2009-06-29T13:36:00.001-07:00

I frequently borrow this device from a neighbor of mine (pictured here), which peels, slices and cores apples. It reinforces my idea that in the design of anything there must be more simple and effective solution just waiting to be discovered. As an amature sailboat designer I am haunted by this contraption as an example of what “could be”, because to me it does exactly what I want to do to an apple for making pie or cobbler. This device exceeds my expectations and even delights me when I use it. This device is not new; it is just new to me.

Something that is not new, but is relatively new to me is the use of ArcGIS Server maps served via WMS in Microstation. Microstation has had the ability to display WMS maps served by ArcGIS Server and other WMS sources for a while now, however with Microstation 8i this functionality includes a user interface in core Microstation that makes it easy to incorporate ArcGIS Server maps into my Microstation drawings.

WMS capabilities are just a checkbox option when publishing maps to ArcGIS Server. After creating maps in ArcGIS desktop, now I personally have a reason to check the WMS service checkbox when publishing my maps to ArcGIS Server. The same maps that I can use in ArcGIS for AutoCAD in the form of a Map Service are also available to me in Microstation as a WMS Service using the same ArcGIS Server.

The apple cobbler my daughter and I made last night tasted good and was fun to make.

Coordinate Systems in ArcGIS for AutoCAD; Is it morning already?

2009-06-10T13:09:00.000-07:00

Traveling from the West Coast to the East Coast has its challenges for business. On my last trip I shared a hotel room with an associate at a large conference; My colleague, tired after a long day, was looking to get to sleep at 10:00 pm, which was 7:00pm my time. My 5 year old back home, wasn’t going to bed for another hour. My colleague then announces he would be getting up at 5:00 am (booyah!) and was asking if he would have a conflict with me getting ready in the morning. Quick calculation in my head… that’s 2:00am!

The Earth is round, so even though we may have an accurate measurement that same measurement has a geographic relevance for a particular place. The watches on both of our wrists were accurately measuring the time in our zone. Trouble was I was out of my zone.

For many CAD related efforts I may be entering coordinates accurately in my zone, be it state plane or UTM or the alike. However, without some means to identify which zone I am in, or more basically what coordinate system my coordinates are depicting, when I am outside that zone things don’t line up.

In ArcGIS for AutoCAD you can identify which coordinate system you are in so that map services from other coordinates systems will automatically line up in the right locations. Likewise when the drawing is added to ArcGIS software it will also line up. By default ArcGIS for AutoCAD will assume that if you are adding a map service within an AutoCAD file without a coordinate system defined you will want your drawing to have same coordinate system as the map service. This may not be true; therefore you will want to select your coordinate system from a list of some 4000 coordinates systems that ship with ArcGIS for AutoCAD first. If your AutoCAD file has a coordinate system definition in an external .PRJ file, ArcGIS for AutoCAD can import that .PRJ file and store it inside the CAD file according to the Mapping Specification for Drawings.

For Microstation files and AutoCAD files not used in ArcGIS for AutoCAD you would copy a .PRJ file of the appropriate coordinates system in the same directory old-school.

Optimizing ArcGIS Server

2009-05-15T13:55:00.000-07:00

One of my hobbies is experimental sailboat design. And, with anything worth designing the challenges are circular and interconnected; weight, drag, stability, complexity, reliability, speed, performance. Optimization is the usually the balance of these sometimes diametrically apposed factors. If it’s light weight, it may not be reliable, or stable. If it’s stable it may not be fast or light. If it’s fast it may be too complex, unstable and unreliable. The reward in exploring a design is when I find that overlooked and elusive idea that truly can overcome the previous limitations and provide an uncompromised optimization. A solution where I can do something I could not do before; faster, lighter, stronger, simpler and better.

Although most of the things that make published map documents fast and efficient Map Services are likewise good for ArcGIS for AutoCAD, there are a couple things that ArcGIS Server IT managers should consider that are specific to ArcGIS for AutoCAD users. Technically, ArcGIS for AutoCAD uses the ExportMapImage functionality of ArcGIS Server to interact with map services.

Therefore the first order of server business for ArcGIS for AutoCAD is to ensure I have not disabled the ExportMapImage functionality on my map server. Secondly ArcGIS for AutoCAD needs an ArcGIS Server geometry service to project the coordinates of a cached map services if they are different than the coordinate system of the AutoCAD drawing. I do not need a geometry service if both the cached map service and the drawing are in the same coordinate system or when the map service is generated dynamically. ArcGIS for AutoCAD will look for the geometry service on the same server as the map and if it doesn’t find one it looks elsewhere on the internet. If a geometry service is enabled on my map server projecting cached maps for ArcGIS for AutoCAD is faster, if needed.

Better yet, to avoid problems with grainy maps caused by excessive scaling, or the performance hit for re-projecting maps, it’s a good idea to publish my map service in a coordinate system AutoCAD users are likely to be viewing the map. I may have casual mapping users who can view the map service in a geographic coordinate system since they really don’t care what the coordinates are, but generally AutoCAD users are working projected coordinates, like State Plane or UTM. If I expect I will have ArcGIS for AutoCAD users I might consider publishing maps in their commonly used coordinate systems.

Although caching the maps on my map server is a good way to speed things up for most ArcGIS map service viewing applications, it is not necessarily faster for ArcGIS for AutoCAD which still requires that a map image be created, and because of the threshold of discrete scales being set for cashed maps, the quality of the map image could be better if the map service was left to be generated dynamically.

Some of these optimization settings may be at odds with other ArcGIS Server best practices. Both are valid, I might consider creating two different map services, one for ArcGIS for AutoCAD to use and another for general users if I notice performance, or image quality issues due to projections. In most cases the differences are minor, but in combination, and with a large number of users it could become significant.

Editing In ArcGIS for AutoCAD?

2009-05-08T11:30:00.000-07:00

I have planted a vegetable garden. I don’t expect it will save me much money on food, but I really enjoy the idea of it. The best places in my yard for growing things are either covered by structures, concrete or trees. To create some more space and to thwart the plans of bugs and weeds, I’ve decided to plant my garden in pots on a terraced rolling cart. It’s like the produce stand in the picture, accept it has bins of plants from which I hope to pick fruits and vegetables.

This may sound obvious, but one thing I’ve learned from past agricultural experiments is that it is best to plant things that I actually like to eat rather than things that are just easy to grow! And it is nice to get plants that can keep producing over time rather than all at once.

If I want to allow someone to use AutoCAD to edit data I have in ArcGIS I can give them an AutoCAD copy of a sub-set of the GIS data using the EXPORT TO CAD tool. Before I export the GIS data I can flag it with a unique code of my own creation. This transaction flag can be nothing more than an integer in a field I call “transaction” or a text field. I like to create a text field, and then use the now( ) expression with the ArcGIS CALCULATE tool to create a time stamp string as my transaction code. This is probably something I should automate using a geoprocessing model; select stuff, ADD FIELD, CALCULATE, etc… EXPORT TO CAD.

A feature class will be created in the AutoCAD drawing according to the mapping specification for drawings, along with the attribute schema for the data.

TIP: I want to make sure to only export a selected set of features to avoid pushing thousands of features back and forth that I have no intention of changing. If I want more data for geographic context, I can publish a map service of the same GIS data with ArcGIS Server. I then use ArcGIS for AutoCAD’s ability to use map services to see the full basemap.

Using the attribute editing tools of ArcGIS for AutoCAD and the AutoCAD graphics engine I make edits to my copy of the geometry and attributes of the exported GIS data. If I trust the edits made in AutoCAD and I am confident that ArcGIS can see the appropriate data in the AutoCAD feature class, I can use those changes to update my GIS data. I want any features that are added, modified or deleted to be updated in the geodatabase appropriately.

Now assume that I really really want the changes I made in the AutoCAD file to replace the existing data flagged by my transaction code and still unmodified in the geodatabase. I select my flagged features with my transaction code in the geodatabase, and DELETE them. I use the modified AutoCAD file to replace the data involved in the transaction with the APPEND tool. New features will be added, modified features will be replaced and deleted feature will not be replaced, and therefore deleted.

This rather crude form of editing should be thoroughly tested in each environment and then only performed on a copy of the production data that is then verified for quality control, before changes are accepted. In this workflow I must also accept the fact that the object identifiers will be changed on all of the features in the transaction including objects that didn’t change, since in this version of the workflow everything you exported was flagged as part of the transaction.

If someone else edits the same data that I intend to be editing in AutoCAD, their edits might be overwritten by mine, or if my transaction flags become out of sync or invalid the workflow could be compromised. It is up to me to manage how transactions like this are flagged and processed. I must clean up after myself and guard the state of the database during transactions. Additional consideration would need to be given for the effects of editing features involved topologies, or networks. The bottom line for this workflow is that I am responsible for everything that happens to the data, there are no built-in safeguards.

On my produce cart now are: blackberries, raspberries, cucumbers, eggplant, carrots, onions, squash and tomatoes, in the fall, strawberries, beans and spinach will be likely additions. I’m making frequent trips to my produce stand for tending, and watering. I will automate the watering with a drip system hooked up to my lawn sprinklers.

I look forward to the harvesting.

Industry Specific GIS Data Models in AutoCAD

2009-04-30T10:55:00.000-07:00

My mature Valencia orange tree is full of fruit, and it will have ripe fruit from April thru August, which means as much fresh orange juice as I want to squeeze and drink from the single tree. My lemon tree is still small, but it usually has at least one ripe lemon on it every month of the year. I planted a baby avocado tree two years ago, still no fruit…

I reap the fruit of the previous owner’s planting and care of my orange tree. The lemon tree I planted is starting to produce, and the avocado tree is an investment in the future for me.

One free benefit of ArcGIS for AutoCAD that I can start working with right away is accessing ArcGIS map services in AutoCAD with ArcGIS for AutoCAD. As a GIS administrator I can immediately connect the AutoCAD professionals in other departments, and AutoCAD-based contractors outside my organization by looking at the common and direct view of the enterprise GIS basemap through a map service.

Another benefit that is growing in importance is the ability for these same AutoCAD users to create GIS-ready data with the tools in ArcGIS for AutoCAD that build content according to the mapping specification for drawings.

I can use industry specific GIS data models defined by various industry experts for GIS in AutoCAD too! Within ArcGIS I simply export a sample geodatabase like the Water Model available on ESRI.com to an AutoCAD file using the ArcGIS EXPORT TO CAD tool available with ArcView, and presto I have the water model industry schema designed for use in GIS within AutoCAD according to the mapping specification for drawings! Used as an AutoCAD template file, blank versions of the schema can be passed along to others to fill up with water-model content, I know that when the CAD data is brought back into ArcGIS it will be readily usable.

Time to pick some more oranges.

Editing GIS Data in CAD: Attributes

2009-04-22T12:26:00.000-07:00

I rented a house on vacation. The house was furnished with cooking utensils and the alike. We packed just our personal stuff that we intended to enjoy while we where there in the new environment. It wasn’t like home; lots of things were different, how things were organized, different interfaces to the appliances etc. We benefitted from having those things there, and not having to pack them. Not surprisingly their stuff was chosen and adapted for a more rugged and minimalist life at the beach. We cooked and played with their stuff, using stuff we brought or bought while we where there. Like all good vacations we took back family memories and experiences that updated and recharged various attributes of our lives.

ArcGIS desktop reads and writes both AutoCAD and Microstation files. In the case of AutoCAD files, ESRI’s mapping specification for drawing allows attributed GIS features to be included in plain AutoCAD files. So what good is that? It is useful for me to create AutoCAD data that will also be used as GIS data and to comply with GIS submittal requirements, but what about as a means for editing ArcGIS data in ArcGIS data sources?

If I want to allow AutoCAD users to make attribute-only edits to my ArcGIS data I can use ArcGIS geoprocessing tools like EXPORT TO CAD, JOIN and CALCULATE to facilitate the workflow. By exporting ArcGIS data to an AutoCAD file with the EXPORT TO CAD tool, the resultant AutoCAD file retains the unique object identifier and feature class organization and attributes of the source ArcGIS feature class according to the mapping specification for drawings. I can make attribute edits to the copy of the data in AutoCAD with ArcGIS for AutoCAD, or any other MSD compliant application. After attribute changes are made to that copy of the data, I can JOIN the AutoCAD version of the data to the original ArcGIS GIS feature class, based on the unique object identifier field and use the geoprocessing CALCULATE tool to move the attributed data from the CAD-based copy of the data to the geodatabase version for each of the attribute fields I want to update.

Good Friday Fact Check

2009-04-10T10:03:00.000-07:00

I’ve been reading some descriptions and interpretations of ArcGIS for AutoCAD from various sources. There seems to be some re-occurring confusion despite attempts to be clear about what it is and does. Perhaps this list will help.

ArcGIS for AutoCAD does not require ArcGIS Server. ArcGIS for AutoCAD is a free download that works on top of plain AutoCAD. All of its functionality can be used completely for free. I can access any free published map services with ArcGIS for AutoCAD as long as I know the URL and have access.

Furthermore, I can view, modify and create GIS-ready data according to the Mapping Specification for Drawings using the feature class management tools that are provided in the free ArcGIS for AutoCAD application, which does not have anything to do with map services or ArcGIS Server. ArcGIS for AutoCAD has tools that work on stand-a-lone AutoCAD to create feature classes with attributes that are recognized by ArcGIS. ArcGIS desktop can directly read the entities in the AutoCAD files as GIS feature classes.
ArcGIS for AutoCAD does not publish map services. To publish map services you need a GIS server, like ArcGIS Server. To publish map services I need a licensed copy of ArcGIS Server. ArcGIS for AutoCAD is a client of ArcGIS Server Map Services, not unlike the free ArcGIS Explorer product is a free desktop client.
ArcGIS for AutoCAD is not designed to compete with AutoCAD based GIS ad-on software. Rather it is a product designed to assist me when I am working with ArcGIS workflows that include AutoCAD. It helps me interoperate between AutoCAD and ArcGIS because I have a way to attribute CAD entities that ArcGIS understands and also clarify how GIS data is organized in my AutoCAD file.
ESRI's mapping specification for drawings is not a software product. It is simply a specification. It is a piece of paper. It is an agreement between ESRI and the AutoCAD user that if AutoCAD files are structured in a certain way they will be understood by ESRI as having a certain format and organization of data and content. It is not meant to compete with any other workflows or software, but rather has been introduced as a proactive means to support ESRI customers that work with AutoCAD or extended teams that use AutoCAD. ArcGIS for AutoCAD provides a free user interface to the mapping specification for drawings inside AutoCAD. ArcGIS software reads and writes this style of AutoCAD data.
ArcGIS for AutoCAD does not provide a means to directly edit ArcGIS geodatabases. It may in the future, but the current release does not generate AutoCAD entities from map service content or any other means supplied in the application. Nor does it allow me to modify features from a map service or other ArcGIS data source.
ArcGIS for AutoCAD does not currently create or edit any other form of GIS data accept pure .dwg data formatted according to ESRI’s mapping specification for drawings. That is a good thing. The data is still pure .dwg with just enough non-graphic entity data to make the entities in the drawing directly usable as feature classes in ArcGIS. ArcGIS data exported to .dwg files is a snap-shot copy of the GIS content written to a .dwg file. It doesn’t mean I might not have a clever workflow to move data back and forth, but the data is not otherwise linked by software.
ArcGIS for AutoCAD supports ArcGIS Map Services and these images are not simply raster images. Map Services are georeferenced, scale dependent cached or dynamic services that are implemented inside of AutoCAD as a custom object that has various configurable behaviors that control the visibility of the entire map service or individual layers in the map service. ArcGIS for AutoCAD also provides a means to query the attribute records of features contained in the map service provided that functionality was published in the map service by ArcGIS Server.
ArcGIS for AutoCAD supports many, many coordinate definitions, all the same nominal coordinate systems supported by ArcGIS Server using a WKT (Well Known Text) string embedded in the .dwg according to ESRI’s Mapping Specification for Drawings.
ArcGIS for AutoCAD does not use any of the functionality of Autodesk Map 3D. Autodesk Map 3D proprietary data organization and coordinate systems are not accessible to the plain AutoCAD user or commercial applications that read standard .dwg files, like ArcGIS for example. It doesn’t mean they are bad, it just means they do not promote interoperability with ArcGIS as a data source. ArcGIS for AutoCAD will co-exist with ad-on’s to AutoCAD including Civil 3D and Map 3D insofar as these include AutoCAD.

Perhaps there may be additional questions that come up in the comments. I’ll add them to the bottom of the list… Starting with #10.

Missing Link

2009-04-09T11:15:00.000-07:00

Oops, forgot to add the link to the AutoLISP routine in the original version of the last post.

One More Time Around the Block

2009-04-03T10:59:00.000-07:00

My birthday is coming up soon and I’m planning on celebrating with an Easter vacation on the beach. The retreat is also doubling as our summer vacation, and payback to my wife for abandoning her every weekend and evening to coach basketball this winter. My daughter is also planning to celebrate her belated birthday at the beach. Her birthday party was also delayed because of the basketball schedule.

In a previous post I discussed some of the reasons I may want to continue to use block attributes as a means to attribute point feature in AutoCAD even when using the Mapping Specification for Drawings to create data for use in ArcGIS.

Here is a new AutoLISP Routine that will build the MSD feature class schema in a drawing based on all of the block definitions and attributes on those block definitions that are contained in a drawing. The included AutoLISP command is called esri_BlockToFC. This tool is useful to generate new MSD feature classes and attributes when moving away from relying on AutoCAD block attributes as a means to store attributes in an AutoCAD file on Point, Line or Polygon entities. It will use the tag name of attributes and generate typed fields according to the any default value you may have specified for a particular ATTDEF. If the default value for the ATTDEF called diameter has a default value of 4.5 then this lisp routine will create an MSD feature class attribute with a floating type attribute. I can override the type of a field using the feature class management panel of ArcGIS for AutoCAD.

The MSD feature class filter criteria created for each feature class will be based solely on the block name from each block. I generally do not need different feature classes for every block in my drawing. I will likely need to use the ArcGIS for AutoCAD feature class management panel to rename feature classes and consolidate blocks, or remove or re-define the filtering criteria for the feature classes that get created. In the case where I might have blocks holding attributes for lines or polygons I will change the feature class type and the filtering criteria. I can use these tools to automate the process of copying attribute schema from my existing block attribute-based data creation workflows to take advantage of the MSD capabilities of ArcGIS for AutoCAD and ArcGIS Desktop. If nothing else it is an example of customizing the ArcGIS for AutoCAD application in a useful way with AutoLISP.

Geoprocessing, MSD and .NET

2009-04-02T12:05:00.001-07:00

“Nothing but net” is a welcome refrain for basketball shooters. I hope you will find these .NET samples connecting AutoCAD with ArcGIS Geoprocessing located on ArcScripts equally valuable.

I enjoyed meeting with the CAD savvy developers at ESRI 2009 Developers Summit. Hello again to all of you who attended our CAD technical presentation at the conference or that met with the CAD team at the breakout session. Karen the co-presenter and author of the samples, has posted the sample code on ArcScripts. This code was demonstrated during our session to connect AutoCAD .NET to ArcGIS’s Geoprocessing tools via .NET for the purpose of extracting data from ArcGIS sources as CAD data. Conversely the samples also include adding data from CAD drawings into ArcGIS data stores. These coding samples are available here on ArcScripts.

The samples are a concrete programming examples of the topic I introduced in a recent blog posting on bouncing CAD files off of geoprocessing.

MSD: Blocks and Blocking Out?

2009-03-27T10:41:00.000-07:00

We’re in the thick of the 2009 March Gladness basketball tournament the equivalent of the State finals for California Home School Basketball, where the lady warriors will be going up against their out of town rivals in the finals if all goes as planned. This is the end of the season and rebounding is going to be our focus. There may be many coaches that disagree with me, but my philosophy on rebounding is that the mysterious act of “blocking out” that eludes many players is nothing more than a continuation of the offensive and defensive flow. The offensive player shouldn’t “block out” 15 feet from the basket anymore than they should post up 15 feet from the basket. Likewise the defensive player needs to deny a cutter to the ball coming off the rim in the same manner they would defending a pass.

Before the Mapping Specification for Drawings the best method for attributing AutoCAD files for use in ArcGIS was to use block attributes for point features. There was really no go way to maintain feature attributes on lines and polygons features. Using blocks with attributes is still a good way to create point features for ArcGIS especially when you are organizing them into MSD feature classes. The block attributes of blocks in MSD features classes are still recognized by ArcGIS like they have been. The question arises when should I use MSD attributes, and when should I continue to use block attributes on POINT features.

The answer is, it depends. MSD attributes are not displayed visually as labels in AutoCAD (this is actually why I did the experiment of using ArcGIS Server Map Services to do thematic mapping on AutoCAD files.) So if you want the attributes to be a form of annotation, blocks with attributes are the way to go. MSD attributes on points have the advantage that they are managed like other attributes according to the mapping specification and can be typed. That is to say they can be INTEGERS, or REALS not just TEXT. All AutoCAD block attributes are of type TEXT. In the future the MSD attributes will likely contain other valuable functionality such as domain constraints.

Good basketball players instinctively block out, and crash the boards for rebounds, teaching players to suddenly block out when a shot goes up as a separate act is rarely understood or successful, because if players can’t anticipate a scoring opportunity offensively or defend their opponent, they are just going to stare at the ball as it bounces mysteriously to another player time after time despite their frustrated efforts.

Controlling ArcGIS Map Services with AutoLISP

2009-03-25T10:56:00.000-07:00

I’m sitting here at the 2009 ESRI developer summit in Palm Springs. Everyone here is thinking about how to customize ESRI software to do really extraordinary things. I thought it would be a good time to share a little AutoLISP routine that I wrote that manipulates ArcGIS for AutoCAD Map Services to create higher resolution images over a larger area than the current view, as disconnected raster references.

This sample AutoLISP uses ArcGIS for AutoCAD Map Services and creates a mosaic/array of resultant images disconnected as AutoCAD raster references. This sample AutoLISP routine uses a comboination of ArcGIS for AutoCAD commands, ArcGIS for AutoCAD API AutoLISP functions and standard AutoCAD AutoLISP routines.

To use it copy the lisp routine to some location recognized by AutoCAD and load the file. Zoom into the lower left hand corner of an area you want to cover with Raster Reference images. And enter the ESRIMapMosaic command at the command prompt and answer the prompts. The resultant .PNG files will be automatically named after the map service in the same directory as the working drawing file. As with all samples you are encouraged to further customize it to better suit your working environment.

Because ArcGIS for AutoCAD uses the current AutoCAD display view extents to determine the view scale for maps generated by ArcGIS server, to get a higher resolution over a larger area you can use this AutoLISP routine to bring the images local to your desktop. Although they are converted to static .PNG Images, you might find value for the higher resolution images as a backdrop. The effect is laying down a mosaic of an area built from tightly zoomed tiles of a higher resolution than is displayed when you rely on a single Map Service image to cover the same area.

Here is the file on ArcScripts: MapMosiac.lsp.

Demo of ArcGIS for AutoCAD

2009-03-24T14:33:00.000-07:00

I Just got back from the homeschool basketball national championships where my daughter’s team finished 24th. They played hard and we had some close games along with some minor injuries. Overall it was a great experience.

With our limited traveling contingent we did not have enough resources to film and take stats for the game. The solution, we recorded the game and took stats by watching the film afterward. Taking stats from the film has obvious benefits over one person taking stats during the game in that you can watch the recording over and over again and you can rewind it to see who really did what. Good plan except in the first filmed game we ran out of room on the camera and missed part of the exciting 4th quarter and our failed comeback attempt that left us 2 points behind at the buzzer. …oh well we’ll get’um next year.

Here is a video overview of the ArcGIS for AutoCAD application updated for the new features of build 200.

AutoCAD Layers to ArcGIS Feature Classes

2009-03-09T12:28:00.000-07:00

Like the Mobius strip, with a little twist what used to have two sides now has one. For those who already use AutoCAD layers as a means to define GIS layers, an ArcGIS for AutoCAD AutoLISP routine can make short work of defining your CAD Standards as GIS feature classes according to the mapping specification for drawings.

The ArcGIS for AutoCAD AutoLISP routine (ESRI_LayerToFC) is a short cut to defining GIS features from your existing drawings. It will make feature classes for each layer containing possible GIS features. If your drawings are primarily organized by Layers this might be a helpful tool to make short work of defining your feature classes in ArcGIS for AutoCAD.

Try typing (ESRI_LayerToFC) at the command prompt of AutoCAD with ArcGIS for AutoCAD loaded and see it work. It is an unsupported sample routine, but it seems useful to me.

To Serve CAD

2009-03-05T10:23:00.000-08:00

Now and then I come across something that is for lack of a better description just kind of cool. I am not sure if it is practical. Just because you can do something doesn’t necessarily mean you should do something. With that disclaimer… let me share with you something cool. Stay with me because this is a little bit “out there”.

I have AutoCAD, ArcGIS Desktop, ArcGIS Server, and ArcGIS for AutoCAD on my laptop. Doesn’t everyone? See the sign post up ahead…? In the twilight zone everyone does. (My apologies to those reading this in another culture and language, and not familiar with the obscure TV references.)

ArcGIS desktop reads AutoCAD and Microstation files directly. If my AutoCAD file contains feature classes according to the mapping specification for drawings, then I can use those feature classes directly and without conversion as layers in an ArcMap map. I can symbolize the resultant features thematically according to the user defined values that they hold. I can color polygons based off of specific values, or vary the thickness of lines based on a range of attribute values, or use different point symbols… etc. I can also use the attribute values to create text labels that ArcMap knows how to place nicely.

I can serve ArcMap maps that I create as a map services using ArcGIS Server. I can use ArcGIS for AutoCAD to consume map services from ArcGIS Server including maps that reference AutoCAD drawings. In ArcGIS for AutoCAD I can edit AutoCAD entities as well as modify entities according to the mapping specification for drawings. Now it starts to get interesting.

ArcGIS Server map services can be cached or they can be dynamic. Dynamic map services are drawn by ArcGIS Server directly from the data referenced by the map document that is being served. If I open the AutoCAD drawing with ArcGIS for AutoCAD that is referenced by the ArcGIS map document, that is in turn being served by ArcGIS Server, and I use ArcGIS for AutoCAD to connect to that Map Service of the AutoCAD file that I am in… stay with me. ...Then when I make a change to the AutoCAD drawing, such as changing a feature class attribute and save the file and refresh the map service, then I see the map that is thematically drawn by ArcGIS Server which is based on the features and user defined attributes of the AutoCAD entities from the AutoCAD drawing that I am in! ...Whew!

Ok, I’ll wait while you re-read the paragraph above… So, I can use ArcGIS Server to do thematic mapping of my AutoCAD data via a map service while I’m in the same AutoCAD file as long as I save the file before I refresh the map service, and as long as ArcGIS Server and ArcGIS for AutoCAD have access to the same AutoCAD file, and the schema of the AutoCAD file doesn’t change. Granted, this is an extreme use of ArcGIS Server, but it is, I think, an interesting exploration of GIS and CAD interoperability, pieces of which you may find useful.

In light of this blog post the roasted vegetarian from the previous post is even more disturbing.

AutoCAD files as ArcGIS Electronic Submittals

2009-02-27T10:23:00.000-08:00

Roasted vegetables or roasted vegetarian?! I was a little taken aback by my first glance at these conference lunch options shown in the unaltered picture above. I think I know what they meant? Subtle difference in words, big difference in meaning. The two words alone are ok, but together they are troubling. (I had the turkey.)

In dealing with the interpretation of AutoCAD data as ArcGIS content it is always better to avoid ambiguities and possible double-meaning through incomplete information or unguided interpretation. In ArcGIS for AutoCAD build 200 you can now specify how your AutoCAD data will be interpreted by ArcGIS. By default AutoCAD files In ArcMap are filtered as feature classes based on their geometric type. Now with ArcGIS for AutoCAD and the Mapping Specification for Drawings, I can specify criteria for additional named feature classes in my AutoCAD drawings. As a bonus any object, not just AutoCAD blocks can hold user defined attributes. This is accomplished with standard graphic and non-graphic entities in a plain AutoCAD drawing and tools included in the new free ArcGIS for AutoCAD application.

Using ArcGIS for AutoCAD to define how my existing CAD standards should be interpreted as GIS layers in ArcGIS is a great way for me to create ArcGIS data using my existing CAD standards. I can define the filter criteria for my feature classes based on the AutoCAD entity properties, the same AutoCAD entity properties of Color, Layer, Line Style etc… that I am using to define my CAD standards. I can for example include multiple AutoCAD layers to build a single GIS feature layer, or be very specific about the Color or Line Style of entities that would qualify as GIS feature for a particular GIS interpretation of my AutoCAD file.

Used in combination, GIS submittal standards can be honored using my existing CAD standards. By defining feature classes in my AutoCAD drawing using ArcGIS for AutoCAD I can follow my existing CAD standards while at the same time building GIS data. This is also great for my consultants outside my organization because they have their own CAD standards, but I want them to create specific GIS layers for me. With the Mapping Specification for Drawings they can correlate their CAD standards one time to align themselves with my GIS requirements and then use the resultant feature layer definitions as part of their template drawings, or import the definitions from the one drawing into any of their new or existing drawings. The consultant can follow any CAD standard they want and still be able to provide me with an AutoCAD file that ArcGIS will understand as having particular ArcGIS feature classes with the desired tabular attributes according to my required GIS schema.

ArcGIS for AutoCAD at the ESRI 2009 Developer Summit

2009-02-24T13:47:00.000-08:00

Recently my high school teammates met to play one last game in our old school’s gymnasium that is slated for demolition. Although I was not able to attend the festivities I was there in spirit. I have been reliving a lot of my high school basketball years while coaching my daughter’s teams after a long sabbatical from basketball. I have really enjoyed revisiting these memories and sharing new ones with my daughter.

When I first started working in the realm of GIS and CAD interoperability I was very busy coding in AutoLISP to build sample applications for ArcCAD (ESRI's retired AutoCAD-based mapping software.) I now find myself revisiting some of those familiar experiences with the new API’s for ArcGIS for AutoCAD. Although I can use other development environments inside AutoCAD to manipulate the AutoCAD file according to the Mapping Specification for AutoCAD, the ArcGIS for AutoCAD build 200 application ships with an AutoLISP API to accomplish many of the things I want to automate with both ArcGIS Server map services and feature class information in ArcGIS for AutoCAD, and accomplishes it in the comfortable and non-threatening AutoLISP framework.

There are a couple of sessions at ESRI’s 2009 Developer Summit that will be addressing customizing ArcGIS for AutoCAD and working with ArcGIS desktop and Server applications with a CAD focus March 23-26 in Palm Springs, CA. I hope to see you there.

ArcGIS for AutoCAD build 200

2009-02-23T09:54:00.000-08:00

S, E, T, GO!

Question: Is this version of the free ArcGIS for AutoCAD application something I should pay attention to?

Answer: ,,, Yup.

Here is the: ArcGIS for AutoCAD Build 200 Press release.

You can download it now from ESRI here: ArcGIS for AutoCAD Download.

MSD: A Good Defense is a Good Offense

2009-01-05T11:26:00.001-08:00

You can be successful in a workflow without necessarily understanding why or how it works. The lady warriors have been playing pretty good defense during their recent pre-season basketball games. In their first regular season game they won by over twenty points. Their defensive success comes from effort, but also by adherence to audible calls from the bench that help orchestrate their actions. Their understanding of why they are moving from one spot on the floor to another is less clear. The coaches need constant attention and oversight to assure quality and control. I for one am hoping to move beyond that and teach the girls how they can be more successful on their own. The girls need to own their individual responsibilities, so that we the coaches can concentrate on the bigger picture of strategy and the overall flow of the game.

GIS and CAD interoperability is similar in a lot of ways where CAD standards and ad-hoc workflows are put in place to be competitive and get the job done. However without constant attention to quality assurance and quality control (QA/QC) things can go bad especually when working with outside organizations. This needed attention is often a distraction of resources that could be utilized to do more strategic and profitable work. The introduction of the Mapping Specification for Drawings (MSD) and the new tools being distributed in the next version of ArcGIS for AutoCAD (more about that soon) are designed to provide a huge benefit to the overall GIS and CAD interoperability workflow and free up resources that would otherwise be focused on creating and maintaining ad-hoc workflows back and forth between GIS and CAD. And this is important, it is free and it will not change most people’s existing GIS or CAD workflows.

BIM, Robots and GIS

2008-11-04T09:26:00.000-08:00

So now your daughter wants to drive? Children have both a fascination and a fear of driving. The luxury of the parental chauffeur is hard to beat… until you find that the chauffeur isn’t going where and when you want to go. Now overcoming one’s fear of driving starts to look attractive. To get the driving privilege you’ll need to actually do your chores, practice piano, be nice to your little sister. Then there is insurance and gas money… before you know it your teenager is jumping through hoops and pealing themselves off the couch, getting up early, and thinking about getting a job!

Ultimately the fate of BIM is going to be determined by whether real benefit from the data can justify the increase in cost of data collection. Using this same logic, a reduction in the cost of data collection helps lower the barrier to entry. It is clear the need to better manage the information in and about buildings and their relationship to the world around them is compelling. Here is a good articulation of the value, and an interesting solution to collecting information that can build a Building Information System that isn’t necessarily derived from 3D CAD at all.

MSD: Bouncing CAD files off the GIS

2008-09-12T15:54:00.000-07:00

Recently I got to speak to literally thousands of you at the 2008 ESRI International Users Conference in San Diego. I’d like to say thank you again to those of you who said nice things about our presentations and this blog. I enjoyed talking with many of you and was intrigued by the work you are doing.

One thing that I was reminded of during the conference was that ArcGIS deskop users should be thinking of ESRI’s support of CAD files in terms of geoprocessing. If know you that CAD files are represented as GIS feature layers and have a good grasp of geoprocessing then I would say you will know exactly what you can do with CAD data in ArcGIS. You can use CAD data, copy it, join with other GIS data, calculate with it, and perform analysis with it. CAD feature layers in CAD files are valid inputs to most geoprocessing tools.

Now that GIS data can be represented in AutoCAD files with MSD feature layers, both the input and the results of geoprocessing models can be an AutoCAD file without special treatment and without losing the GIS attributes. Using the append to CAD file parameter on the EXPORT TO CAD tool, both the input and the results can be the same AutoCAD file. Think about what it means to perform GIS procedure like a spatial join or an overlay operation on CAD entities when ArcGIS desktop understands that the CAD entities in your AutoCAD file belong to an MSD feature classes, and what it means when you can output a GIS feature layer to an AutoCAD file also as MSD features. I call this bouncing a CAD file off of the GIS. The input and the results along with the GIS attribution can be reported right back to the AutoCAD file.

MSD and EXPORT TO CAD

2008-08-18T15:49:00.001-07:00

The Balloon Whisperer

I decided to have a traditional picnic in the park last week. We packed a basket, blanket, sandwiches, salad, and a fresh pie we had made the evening before. We found a nice little park in the canyon and enjoyed a family time on the grass under some shade trees in perfect weather. My youngest daughter Evie was enjoying the freedom of running carefree in the open field when I spotted off in the distance a bunch of pink balloons that had evidently escaped from some celebration miles away. One tradition I have with my daughter is to pick her up into the air to see if she can reach the moon. I hold her up and she reaches as high as she can. Each time we expect that maybe we might actually reach it, but when I ask her if she can, she says, …no, its too high.

Busy running to and fro in the open field I attempted to focus Evie’s attention on the significant collection of balloons floating in the distance. My daughter Evie loves balloons. After pointing out the balloons my wife and I noticed the balloons had taken a definite path toward us. They were still very high, but heading in our direction. When the large bunch of balloons neared the edge of the field I thought that it might make the reaching game a little more fun since they were coming toward us. So, I gathered here up. She reached with outstretched arms and fingers while I lifted up on my tippy toes… Then a surreal alignment of child expectations, a bunch of pink balloons, and wind currents sent the fully inflated helium decorations purposefully plummeting to earth from out of the sky directly at us! In the moment of truth a gust of wind sent the balloons racing over our outstretched hands, but as I turned round 10 feet behind me they were collected on the face of the baseball field’s backstop . I walked up to the backstop and pulled the pink bunch of balloons from the chain link and handed them to my delighted four year old. I then turned to my wife and older daughter, and together we marveled at what had just occurred. Amazing.

The default functionality of the ArcGIS Export to CAD tool creates AutoCAD files with MSD encoded data. The GIS feature layer name is used as the AutoCAD layer name and the MSD feature class criteria to define the entities belonging to that feature class in AutoCAD is that same < name =" Feature">. All the attributes included on the exported GIS layer are automatically included as attributes on the entities. Likewise any fields from joined tables would also be included, because they are included in the feature layer.

Using the default functionality of the ArcGIS 9.3 EXPORT TO CAD tool creates attributed AutoCAD files with GIS encoded data. To the AutoCAD user the data is still standard AutoCAD entities with standard CAD entity properties, it just has a little bit extra to make it more useful for those who know where to look for it. These attributed AutoCAD files are created without effort, but are created with the potential to be very effective in sharing GIS content. All you have to do is reach out and grab it.

ArcGIS desktop and server applications read MSD encoded AutoCAD files. The next version of ArcGIS for AutoCAD will also include free tools to read and write this information. Published in the ArcGIS 9.3 online help are sample scripting tools to allow AutoCAD users to work with this information from within AutoCAD. API Samples are available in AutoLISP, the programming language syntax of C# - .NET, and DWGDirect code (The DWG Software libraries published the Open Design Consortium).

MSD: Why MSD?

2008-08-11T09:24:00.000-07:00

Into the Wilderness

I am planning a camping trip with my daughter. I grew up understanding that the term camping was a word reserved for the act of wilderness hiking. Our family made a distinction between hiking and lesser forms of camping like car-camping, which is prone to result in too much stuff and too little place to pack it. I later learned that camping might also apply to vacationing in a cabin in the Northeast. In my youth I would often hike a week at a time in the national parks of Washington State and never see another person; deer, bears, mountain sheep, chipmunks and mosquitoes, yes, but no other people.

In planning this short overnight hike with my daughter I am contemplating the minimum amount of gear I will need to enjoy the trip. I am a firm believer that the key to camping is comfort! It is a family creed.

As with many things in life, the idea of carrying everything you need to be comfortable up a steep mountain can create opposing requirements. If you pack too much gear you won’t be comfortable carrying it. If you don’t carry enough gear you might be miserable without it.

Packing GIS data for the CAD wilderness is what MSD is all about. There are many different ways to organize data in an AutoCAD file. There are also various strategies to associate attributes with entities. These include attaching external databases, linking entities together and leverage block attributes for polygons and lines as well as point feature, adding simple text. Extended Entity data is another way to add additional information in the dwg file, most of these lack a user interface all have significant limitations. Xrecords, their container objects, the Extension Dictionary and the Named Object Dictionary, are the modern mechanism for storing non-graphical data and attaching them to entities in AutoCAD.

The Mapping Specification for DWG (MSD) is ESRI’s response to evolving technology. Leveraging these methods of storing information in a well defined and consistent way allows GIS information to be encoded directly in the drawing without resorting to the pitfalls of implementing and supporting AutoCAD custom objects that are powerful yet ambiguous additions to the DWG/DXF file and are impossible to use without the application that created them.

MSD allows ArcGIS users to share feature class data, feature class organization, and attribution with plain AutoCAD users. Likewise standard AutoCAD users can create rich GIS content with attributes for future use in ArcGIS and their own AutoCAD application needs, knowing the resulting data created in AutoCAD will be directly usable in AutoCAD and ArcGIS. Most importantly MSD allows CAD draftsman to create standard AutoCAD entities using their existing CAD standards to create this data. MSD uses standard CAD entity properties to define the criteria for inclusion in a GIS feature class and therefore uses rather than replaces existing workflows.

The MSD specification is published here in the CAD Section of theArcGIS 9.3 online help.

MSD: Leveraging CAD Standards

2008-07-01T11:37:00.000-07:00

Which came first the Grand Canyon or the river at the bottom of it? Did the Colorado River carve it, or fall into it? By just looking at it certainly seems like the later. I got a chance not only to visit the Grand Canyon on my recent trip, but also followed the headwaters of the Colorado River down the Rockies into Utah until it headed south to the Grand Canyon while I headed west. Southern Utah seems like another even bigger Grand Canyon from the highway…just without a river.

Instead of defining a whole new path of interoperability, the Mapping Specification for DWG, MSD, falls completely within the existing DWG file data constructs and file format to provide a means to let GIS information persist between ArcGIS and AutoCAD workflows. In ArcGIS 9.3 a small change was made to the way CAD files were read to look for a simple query and entity attributes encoded on the entity’s extension dictionary in a DWG file.

I often need to share basemap parcels and attributed infrastructure data from the enterprise GIS with private developers and design contractors that use simple AutoCAD. Using ArcGIS 9.3 these contractors can use the GIS information in plain AutoCAD. Previously the best I could do was create blocks with attributes as points and simple geometry. Sharing attributed lines and polygons was always awkward in plain AutoCAD.

In AutoCAD I can add information exported from ArcGIS. The GIS feature classes when exported create MSD feature class definitions and a copy of the GIS schema in AutoCAD for me to use. I am now able to populate attributes on standard CAD entities using that schema. Inside AutoCAD I can simply add to the data on the AutoCAD layer that is used as the MSD feature class definition criteria. If ArcGIS ever opens the DWG file again it will understand the new information as belonging to that MSD CAD feature class.

Feature Class groupings in MSD are based on a simple CAD property-based filtering query. It is very similar to the concept of a definition query on a CAD feature class added to ArcMap. Instead of creating data in a specific data or custom object somewhere in CAD, I define which entities in a CAD file participate in the feature class. Entities that satisfy the filtering criteria are considered part of the feature class.

I think it is best to use the most basic criteria to define the MSD groupings such as CAD layer names, however more complex criteria can be used. Since most CAD Standards use Layer names as the primary method of organizing data now, by defining an MSD feature class based on CAD layers or combinations of CAD Layers, I can build GIS-ready data with only minor changes to my existing CAD workflows. MSD feature classes are usable in an AutoCAD drawing either by adding the MSD feature class definition within AutoCAD, by adding entities to data exported from ArcGIS, or by utilizing a seed file with the feature class definitions already defined from either or both sources.

What's New in ArcGIS 9.3 for CAD: MSD

2008-06-25T11:43:00.000-07:00

I just got back from my first visit to the Grand Canyon. I have flown over the Grand Canyon countless times, but this time I walked right up to the edge of it. I was surprised at the many spots in the park’s public viewing areas that you can literally walk right up to the edge of the Grand Canyon without guard rails and look down! In some ways it was refreshing to see that people were trusted with some level of personal responsibility for not falling in, but at the same time as a parent of an active 4 yr old it was a little disconcerting!

I will try to resist metaphors for closing the chasm between GIS and CAD and simply introduce this series on what is new in ArcGIS 9.3 desktop for CAD. The list of new features in ArcGIS 9.3 desktop for CAD are few in number, however the magnitude, and scope of new uses for these features are many. I will expand on some of these in a series of posts following this one.

I will also make some references to the next release of, ArcGIS for AutoCAD here, which will be ready a short time after the general release of ArcGIS 9.3 desktop. ArcGIS 9.3 desktop is scheduled to start shipping at the beginning of July 2008.

Improvements in ArcGIS 9.3 desktop for CAD address the two most common needs expressed by GIS users for AutoCAD; the first, how do I share my GIS data with AutoCAD users? And secondly, how should I organize data in AutoCAD to make it the most useful in ArcGIS?

ArcGIS 9.3 now reads and writes GIS feature classes from and to AutoCAD files using a technique that employs standard AutoCAD extensible data constructs. ESRI’s implementation of this DWG encoding technique is called the Mapping Specification for DWG or MSD. If I create data in a DWG file using this data encoding technique I can specify GIS feature classes in AutoCAD files using standard AutoCAD drawing entities and data structures. The drawings are still plain DWG data with CAD data objects to define how the entities should be grouped and entity-specific feature attributes.

MSD’s main features are:

The ability to store a named coordinate system inside the AutoCAD file
The ability to define which entities in a drawing qualify for a specific GIS feature class
The ability to define a set of attributes for a given GIS feature class
The ability to store feature attributes on entities in the drawing

The ArcGIS 9.3 EXPORT TO CAD geoprocessing tool creates MSD-defined GIS feature classes whenever GIS feature classes are written to AutoCAD files. Instead of forcing my AutoCAD friends to understand a Shapefile, other intermediate GIS formats, or buy ad-on products, I now give them attributed GIS feature classes directly usable in their native AutoCAD environment.

Future versions of the no-cost ArcGIS for AutoCAD will include ESRI’s version of tools to create, edit and view MSD stored feature classes within the DWG file. I can also build tools with my own AutoCAD API’s to work with the MSD data. The new ESRI Resource Center ArcGIS 9.3 content will soon include a detailed specification and examples of the DWG data constructs used for MSD.

ArcGIS 9.3 desktop, ArcMap/ArcCatalog will recognize MSD feature classes whenever it reads an AutoCAD file (dwg/dxf) with data is encoded according MSD. Working with the MSD-defined CAD feature classes will be exactly the same as working with the standard POINT, POLYLINE, POLYGON, MULTIPATCH and ANNOTATION CAD feature classes. MSD-defined CAD feature classes will appear along with these standard CAD feature classes and will include just those attributes I have defined for the MSD feature class.

Because MSD leverages the existing CAD techniques I already use in my CAD standards to organize data by layers, color and other symbolic variations, I don’t have to require a change in the way my draftsman work. The MSD feature class definition is like a stored query, or the definition query of an ArcMap layer. MSD feature classes are simply pre-filtered CAD data with their own feature attributes stored within a DWG file.

More to come…

Donuts, Whole and Holes

2008-05-15T13:20:00.000-07:00

My favorite donut is a french crueler. I like the thought of apple fritters (often the size of the average US county). I am seldom ever glad afterwards that I ate one. I like chocolate covered cream filled donuts. For whatever reason, I am convinced I could easily eat an entire dozen Krispy Kreme donuts and still be lifting the lid of a closed box to see if there are any more. Maple bars are pretty good too. I’m not sure I understand what the hard cake donut or sprinkles have to do with anything… no accounting for taste I guess. I think the purpose of the sprinkle-donut’s existence, is the same as the black licorice gumball, it exists to mock anyone who is too late to choose something else.

GIS Polygons come in various forms. The solid polygon, like a maple bar or apple fritter, the polygon/donut with one or more holes, a polygon surrounding another polygon (filled donut), and a collection of polygons considered one polygon (One Krispy Kreme just doesn’t seem like enough). GIS Polygons can also be overlapping and non-contiguous.

In CAD, SOLIDS and HATCHES are the real polygons; closed POLYLINES are really linear boundaries, not the polygon itself, but still interpreted as polygons by ArcGIS. It is more common in CAD not to worry about closed polylines at all, and just draw the linear boundary network that can be visually inferred as polygons.

To create donuts and multipart polygons (like the Hawaiian Islands as one feature) in CAD, which are in turn interpreted as such in GIS I can create an AutoCAD block of the multiple entities like closed POLYLINE, CIRCLES, etc... ArcGIS consider all of the sub-geometries of CAD blocks to be a single feature with multiple parts. Multiple points, lines or polygon geometries can still be a single entity in a CAD block insert, which are interpreted as mulit-part features by ArcGIS. The CAD BLOCK INSERT is also considered a single point whose geometry is the insertion point of the BLOCK INSERT entity. I typically use blocks as symbols rather than as primary geometry, but this is a useful exception. Both are valid uses of blocks in CAD.

A way to generate donuts from standard concentric CAD polygons is to use the ArcGIS FEATURE TO POLYGON tool. It will cut-out the holes making both the donut and the hole a new polygon. This is the same tool that can create polygons from a set of lines. The tool will break multiple polygons into single polygons, so a combination of using COPY FEATURES and FEATURE TO POLYGON might be required to get my desired result.

GIS and CAD Signs, Symbols and Fonts

2008-03-25T09:57:00.000-07:00

While driving to Oklahoma for the National Christian Homeschool basketball championships this month, I and three other parents rotated driving duties for the 21hr non-stop trip along much of Route 66 (I-40) from California. I pulled shifts in the overnight hours getting to watch the sunrise over the steering wheel, and one shift included a morning snow storm near Flagstaff on the way home. My daughter snapped the accompanying picture in the middle of the night at one of our driver rotation stops somewhere in No-Where New Mexico. Looks like the sign has seen a hard life and was even reused from some signage in days gone by.

At the tournament our girls were one of the youngest teams in the 18yr old and under division and won 3 of their 5 tournament games to finish 21st. Finishing up one spot higher than their initial ranking with a loss to the Indiana state champions and a good team from Missouri that fielded a talented All-American player. We met coaches, parents and young people from all around the country. We had a nice time talking with one team from Wisconsin earlier in the week that we ended playing in our last game. We even sat with them at the awards ceremony. We asked the Wisconsin girls if they had enjoyed meeting other girls from around the country, their point guard gave us a troubled and confused look and responded, 'Girls!?... we’re meeting BOYS!'

One of the primary point symbol types supported by ArcMap is the use of true type-fonts as marker symbols. I use true-type marker symbols in both ArcGIS and CAD when I want the symbols to be the same in both the CAD and GIS versions of converted data. Although I have more flexibility in the creation of cells and blocks for CAD symbology, the ability to reference existing ArcGIS marker symbols in a true-type font can be easier than recreating a CAD symbol set of the GIS marker symbols for interoperability. The trick to getting the ESRI marker symbols in CAD is to create CAD text rather than points. The ArcGIS Export to CAD tool available with an ArcView license, allows me to export point features as CAD text by overriding the default [CADType] with TEXT and then specifying the Unicode character or formatting code string in the text value stored in the [TxtValue] field of the point feature layer’s table.

I can specify the right symbol with CAD formatting syntax in the text string recognized by CAD (ie: [\U+0073], or use the keyboard short cut to type in the actual Unicode value in the string once I’ve done a little research to find the values of the symbols I want to use. Finally to get the right symbol in CAD I need to have access to the same true type font in ArcGIS as in the CAD system. Export to CAD will then use the true-type font referenced by the [TxtFont] field that I include in the feature layer attribute table or an existing CAD font style based on that true-type font that I could reference in a field called [TxtStyle].

Luckily we don’t have to travel for the final games of the year. Wish us luck as we play this week for the California State Tournament Championship.

Import From CAD and Chainsaws

2008-02-26T14:02:00.000-08:00

When someone is talking on their cell phone in the car and you’re riding along, you really can’t help but eavesdrop on the conversation, albeit one-sided. I recently heard this from a friend of mine while talking with his 8yr old son on the phone:

…Did you get all the leaves picked up? ...How about sweeping the back porch? ...and the grass?.... the what?, …why? ... No buddy, you don’t need a chainsaw for that!

The girls in the back seat immediately tuned in at that last exchange. His sister quickly asked, “Chainsaw?! What is Riley doing with a CHAINSAW?!”

The right tool for the job may be less powerful and simpler than the one I might first think. There is a geoprocessing tool in ArcGIS called Import from CAD. Judging by its name, many people gravitate to the tool to make use of CAD files in ArcGIS. Its original design was to generate a normalized view of a CAD file for dissecting and reassembling into all manner of difficult and sophisticated workflows. However for most purposes it is more than overkill, it is much more work than simply opening and using a CAD file directly.

ArcGIS reads CAD files as GIS content and the process of Importing is not necessary. I can create GIS data sets like Shapefiles, or Geodatabases simply by opening a CAD file and copy-and-pasting or, using any number of tools that copy data such as Copy Features, Merge, Append, Feature Class to Feature Class, etc…

The Import From CAD tool creates a Staging Geodatabase that is a highly normalized set of tables that mimics the actual internal organization of a CAD file. The imeadiate result is less directly usable than the default CAD feature classes created by ArcGIS when it opens a CAD file. In fact when I do use the Import From CAD tool the first thing I usually look to do is link the tables together in a useful way, then create a subset of the data, and copy that data to a Geodatabase. Opening up a CAD file and using the Feature Class to Feature Class tool does that for me in a single step.

Import from CAD is a tool that does handles SPLINE geometry better than the default CAD file direct read, and can access AutoCAD Extended Entity Data. However, if I am not working with this type of data there is little reason for me to bother with the tool.

In like manner, just because a chainsaw can make short work of a rose bush, it may be just a little overkill, resulting in even more pieces for me to pick up after I’m done.

GIS and CAD Windfall

2008-02-15T13:36:00.000-08:00

The fortune cookie after my dinner the other night claimed that I would enjoy a windfall. There was some discussion around the table as to what the definition of a windfall was, and the origins of the term.

Webster’s defines it thus:
1 : something (as a tree or fruit) blown
down by the wind

2 : an unexpected, unearned, or sudden
gain or advantage.

I didn’t think much of it at the time, but when I was taking the trash cans out to the curb that windy night and a lotto ticket came cart-wheeling along the ground to my feet,... I was intrigued. It was trash night so scraps of paper blowing around wouldn’t necessarily be uncommon, but a lotto ticket!? Surely the stars were aligning and good things were happening!

I wasn’t sure if the lotto drawing had already taken place or if the ticket was still alive. The data on the ticket in itself was not enough to tell me much of anything. However a quick check on the internet to the lotto website winining-number-server gave me my answer.

Two independent pieces of data that just happen to show up in the same place, although intriguing don’t necessarily mean anything at all. GIS and CAD interoperability is more easily trusted when I get my information right from the source, whether that source is GIS or CAD. When in ArcGIS I can use the contents of a CAD file without creating a copy of it. I certainly can make a copy of it in a GIS format if needed, but sometimes CAD file is the proper source and should be included in a map as such. The same can be true when working in CAD, getting a copy of data from the GIS basemap in a CAD format although useful can be prone to getting out of date or losing the context of how it is used in a map. How GIS data is symbolized is a large component of the value of GIS-generated maps. Directly accessing the GIS basemap from ArcGIS Server using ArcGIS for AutoCAD is one way to ensure I've got the most up to date and relevant information in its proper display format inside AutoCAD.

There is a movie of ArcGIS for AutoCAD on the same page where I can download the application for free. For more information on working with CAD files inside ArcGIS you might consider some of my past articles on the subject.

Alas the lotto ticket was no winner… perhaps I should have played the numbers printed on the back of the fortune cookie fortune instead… hmmm... I’ll let you know!

Georeferencing and the Road to Oklahoma

2008-01-25T15:33:00.000-08:00

Basketball season is in full swing with multiple games most weekends. This year we’re fielding two teams a JV and a Varsity team. Like last year our varsity team still includes all underclassmen one 11th grader, three 9th graders and an 8th grader. In the first round of league games the girls remain undefeated. This year the girls are attending both the California state tournament and the National tournament in Oklahoma as an 18 and under team (last year they won the California tournament as a 14 and under team).

Several different divisions will be hosted at the National homeschool event. Our girls will be competing in the 18 and under all-comers group against various teams from around the country. There is a higher division we will not play, seeded from regional tournaments which field teams more at the AAU club level of play. Regardless we will be stretching out from our local athletics organization to a bigger collective enterprise. We will likely participate in contests against teams that out match us in age, skill, speed, strength and experience. This is nothing new for the girls; it has been true for these girls all the years I have coached so far, albeit now they will set their sights on a higher level of play. There they will be integrated into the bigger picture: some of the athletes competing in Oklahoma will go on to play basketball at major universities.

Often a CAD file is drawn in a local coordinate system. When the drawing depicts spatial information it can be drawn accurately without having to be tied into a global coordinate system. However there may come a time when that drawing needs to participate at a higher level and be brought together in a mapping context with data from many different sources. Tools in ArcMap can quickly reposition a CAD file and integrate it into the bigger picture without modifying the CAD file.

Before I start I’ll need to know where two points on the CAD file should match up to two points in the map. I use the Georeferencing toolbar in ArcMap. There are several different tools on the toolbar to support different workflows. Here is how I like to use it. First I load the CAD drawing and make sure one of the CAD feature layers are listed in the drop down of the georeferencing toolbar. (Doesn’t matter which CAD layer POINT, POLYLINE, ANNOTATION, POLYGON, etc...) Next I zoom to roughly the place on the map were the CAD drawing is to end up. I don’t bother zooming out to the position of the CAD file, instead I use the fit to display tool on the menu to quickly get the CAD file in the map frame so that I can pick control points. For accurate placement I will turn on my ArcMap snapping so I can pick control points exactly based on existing geometry. If the CAD file needs to be rotated I might use the rotate tool to get the drawing closer to its final position… then only if it makes it easier to pick the points. I sometimes use the interactive scaling tool for the same reason. Most times I just fit to display and pick the four control points and I’m done. I select the update georeferencing option and the tool creates a .WLD file for me that will be read from now on to put my CAD file in the right place.

Now the coordinates are always adjusted into this position. At this time I can choose a coordinate system for my CAD drawing so that if I ever need project its coordinates along with the map or during some geoprocessing operation it will work.

BIM: What’s Cooking?

2008-01-09T16:01:00.000-08:00

I took some time off over Christmas break, and at least from a food perspective the vacation was characterized by diverse types of bread making/eating. I made cream puffs, English muffins, bagels, pizza dough, and cinnamon rolls from scratch. These are different types of bread with sometimes very similar ingredients. Muffins, puffs, crust, rolls, all different words for essentially the same thing… bread. Arguably these required vastly different workflows for different food applications and sometime unique ingredients. I really want to make some more English muffins; I never thought they would be so easy to make, yum.

I attended a recent BIM Conference in DC. As an active listener at BIM conferences I am looking at how existing GIS applications that work with buildings are keeping pace with the emerging technologies and more importantly the emerging expectations of what may be called BIM.

For many BIM continues to hold the expectation of an over-arching technology where the building information models and their explicit definitions are the key to making better decisions for an ever-growing and seemingly unlimited list of applications.

I have a growing appreciation for the efforts of organizations promoting standards and starting conversations that can help put scope and context to efforts in the building industry to reduce waste and promote better practices. The standards themselves are not an information system, but they do serve as a powerful means to define the semantics of how to ask better questions and the context for new information systems applications. They challenge the building industry to consider new ways to improve how things are done.

I heard it said a number of times at this conference and at other conferences that workflows rooted in the trade guilds of antiquity, frustrate the modernization of the building industry. These hindrances are so strong that it was said productivity of designing and constructing buildings in the modern age has actually decreased rather than increased! Other industries such as manufacturing it is said have greatly increased their productivity through modernization, integration and automation. Messages directed to conference attendees suggest that if they do not heed the warnings, the building industry could be categorically replaced by what I will call “building manufactures”.

Consider a company that designs and builds airplanes or cruise ships… what software and workflows do they use to plan, design, construct, and build their structures? A cruise ship is essentially a city, with housing, shopping malls, security, restaurants, parks, sanitation systems, electrical production and distribution systems… take off the propellers and remove the requirement that it needs to float and what do you have…? Perhaps there are useful solutions that already exist in a number of places in slightly different forms.

GIS seems to be well positioned to benefit from the efforts of BIM data standards development as another well or poorly structured data source that can benefit from geospatial visualization, computing and management. If you consider a building can be a geographic feature then the GIS is a fine BIS (Building Information System) for many existing applications related to site selection, planning, operations and management of buildings. Assuming you have the tools to read/write and analyze the data for a given information system application there is nothing special about a building that disqualifies it as just another GIS system of data. As I see it right now GIS excels with geographic features to visualize, compute and manage all different types information system applications.

You can break-down the pieces of a building into individual features or ingredients. When you consider a BIM as a source of content, much like a CAD file is now only better structured; it becomes another useful source of data you can manage in an information system. GIS is not a BIM in any sense, any more than a cream puff is like an English muffin. I can cook up something worth while by using the ingredients in the BIM along with other spatial data in my geographic information system. How and what I mix together and what I leave behind on the shelf greatly depends on what I’m making be it a facilities management application or emergency response application, etc... In the case of the English muffin it was Eggs Benedict, and for the cream puffs it was sausage and cream cheese filled lunch pastries.

CAD Standards from GIS with Seed Files

2007-12-14T14:08:00.000-08:00

As the assistant coach for my daughter’s high school basketball team I have the ability to influence, but not always to decide. I can make suggestions to strategy and present ideas, but ultimately the decisions belong to our head coach. He and I have our areas of expertise and because we have a good working relationship we submit to one another in those areas. One way to describe my role on our team is as the rear driver on the ladder truck. The head coach is driving the truck with everyone on-board to our destination. I am at the back steering to keep us on the road.

When working in organizations where there are distinct GIS and CAD related activities there is often one group that takes the lead and another one that supports the overall objectives of an organization. Certainly when the goal is to WIN the team functions better when the coaches aren’t taking things in different directions.

Coordinated efforts to move data back and forth can come from mandatory decrees that come from on high, working together (preferred) , or as a result of good unilateral planning as in the case of one strategy implemented by Truckee-Donner as a unilateral program where the CAD group is not under one authority, but rather is attempting to support any number of contractors not directly under their control.

One practical way for me as a CAD manager to get better CAD files from my GIS group is to sit down with my GIS manager and provide him with a CAD seed file that already contains my coordinate system and CAD layer and symbology standards as a template. This by itself can greatly enhance the readability and use of CAD data generated by the ArcGIS EXPORT TO CAD tool, or the ArcGIS Data Interoperability Extension. Both ESRI software tools that create CAD files from GIS content have the ability to explicitly define to exacting standard entity level symbology with a multitude of configurable CAD property designations. However, with my layer-based symbology standards I can supply my seed file in anticipation of CAD entities placed on those layers to greatly simplify the process. The GIS task to generate good CAD data then only requires that I push data out to the correct CAD layers, and I get the symbology I want.

Fast Break Projection On-the-Fly

2007-11-16T11:37:00.000-08:00

Basketball practice has started for the Spirit Preparatory Academy Lady Warriors, and this year we coaches are focusing on our team’s fast break. In basketball if you can run a successful fast break offense all you have to do to score an easy basket is to have one-more of your players run down the floor faster than that of the opponent’s. Similar to the adage that when being chased by a bear, I don’t have to run faster than the bear; I just have to run faster than you!

Running the fast break in basketball greatly simplifies the game, but requires that my team be organized and focused on the goal of moving with purpose down the floor whenever our team has the ball. This style of basketball requires preparation in advance of both structure and conditioning. If our team has poor positioning, or spacing running down the floor, as to allow one defender to defend two players because of their proximity, or if our players don’t have the physical stamina to repeatedly run down the floor, the fast break doesn’t work.

When I create Microstation and AutoCAD drawings from GIS data many times I am supplying design reference and context for new design work that will be incorporated back into the GIS basemap latter in a project’s life cycle. There can be a practical need to work in different coordinate systems for local design work verses the storage of regional basemap data. Or, in some cases the need to work in different coordinate systems becomes a matter of an organization’s arbitrary preference for one or another coordinate system based on any, or no reason at all. I can change the coordinates of the CAD data I create from GIS data using the ArcInfo EXPORT TO CAD tool in ArcGIS 9.2 service pack 4. Starting with the ArcGIS 9.2 Service Pack 4 release, the EXPORT TO CAD tool will honor the coordinate system defined in the projection file (.PRJ) of the target output CAD file. This means GIS data stored in a UTM meter’s coordinate system can be output to a Microstation design file where the .PRJ file designates a State Plane coordinate system in feet, and the CAD elements being created from the GIS features in UTM will be generated in the correct State Plane location in feet within the Microstation design file.

When using the ArcInfo level licensed EXPORT TO CAD geoprocessing tool starting with ArcGIS 9.2 Service Pack 4, If no .PRJ file already exists for the target or seed CAD file the coordinate system of the input data will be used as for the coordinate system of the output CAD entities, and a companion .PRJ file will be generated for the CAD file automatically.

For Microstation design files it is necessary to set the design cube/plane coordinates definition to ensure proper behavior. I need to ensure my Microstation design plane/cube and its units are adequate set to store the GIS information in the .DGN file. To trigger the new functionality of the EXPORT TO CAD tool I need to identify which coordinate system the coordinates in the Microstation file will represent. I do this using a companion coordinate system definition file .PRJ.

The first of these two steps to define the units and design cube/plane is a purely a Microstation process usually set as part of the Microstation seed file creation. This process is a purely mathematical requirement of how Microstation will be used to record your map as a file of vector geometry. The other process, the creation of a .PRJ file, is specific to ArcGIS which identifies the coordinate system and how the information in a CAD file relates to our round Earth. Just like the execution of the fast break in basketball preparation early in the season makes the players work together more smoothly, and enables success in the game.

AutoCAD .DWG files don’t have the concept of a design cube/plane, but do use the same .PRJ companion file strategy in ArcGIS for identifying the Cartesian coordinates contained in an AutoCAD file and how they relate to the round Earth’s spheroid. The same information stored in the .PRJ companion file can also be included inside the .DWG file according to the techniques starting to be used in ArcGIS for AutoCAD.

Consult you Microstation documentation for the proper creation of coordinate definitions and units for your Microstation Design files and seed files, and use the ArcGIS desktop or online help in the creation of .PRJ files.

ArcGIS for AutoCAD 2008

2007-10-17T16:01:00.000-07:00

My youngest daughter just got a pet turtle. Actually it’s a tortoise. Growing up I don’t recall ever making the distinction. In fact I thought there were land-turtles and sea-turtles and those snapping turtles that lived in lakes and ponds. I have had a similar confusion with rabbits and hares, and frogs and toads; different animals with similar looking features. I was recently told a story (I have no idea if it is true) about a tortoise that was mistaken for a turtle and thrown into the family swimming pool by some visitors. The tortoise sank like a rock to the bottom. When the owner came home he attempted a rescue giving the tortoise “mouth to mouth resuscitation” to revive it. Apparently the tortoise went into hibernation at the bottom of the pool and was saved.

Like the terrestrial tortoise and the swimming turtle, mixing CAD and GIS environments can sometimes be troublesome. ArcGIS for AutoCAD lets me access the other world. ArcGIS for AutoCAD is like an under sea rover. I can use an underwater robot to serve me by sending me samples and providing me images of the water world below. I control the exploration safely from the deck of my boat. For many types of exploration this is much less difficult than a submarine or strapping on the scuba gear. Similarly accessing GIS maps with an internet connection from within AutoCAD is an easy and safe way for me to use the GIS basemap. The maps are generated by the GIS and I see the finished map and get to query its features no matter where or how the GIS data is stored and no matter what format it is stored in. Just being able to see the exact GIS map in the right place without having to convert, translate, symbolize or even find out how to access the data sets is a powerful thing.

Sometimes I use ArcGIS for AutoCAD solely as a way to see GIS published imagery inside AutoCAD. ArcGIS knows how to make maps with imagery and ArcGIS for AutoCAD can access map services created by ArcGIS, so it just works.

I see the new version of the free ArcGIS for AutoCAD is available for download on ESRI.com that now supports AutoCAD 2008. The new version supports the accessing of map services with different coordinate systems. The new version also ships with a host of predefined coordinate system files (.PRJ’s) that can be loaded into the drawing. ArcGIS 9.2 sp3 will recognize these internally stored coordinate system definitions.

ArcGIS Server Services and CAD

2007-09-11T11:27:00.000-07:00

I had an interesting assortment of experiences with services last week, and I thought I’d share some of them. First there was the happiest most energetic technical support person that I have ever talked with. The support person from T-Mobile used the words excellent, super and totally in response to every question I asked, and cheerfully answered every one of my technical questions effortlessly and with unadulterated effervescence! This person must have been a cheerleader, president of the honor society and someone who loves cell phones and everything about them! I hung up the phone, looked at my wife and spontaneously gave her a cheer with accompanying hand motions exclaiming Excellent!

Another day, I came home to a stopped-up drain where the bathroom sink was now draining into the bathtub. My efforts to unstop the drain with a handy $3 hose attachment, which almost always worked…didn’t. I went to the hardware store for liquid drain cleaner, which in my experience, never works. Faced with 4 different products I chose the one with the bright guaranteed to work star on the packaging. I listen to a radio station where most of the products advertised for whatever reason are scams. Weight loss, memory improvement, useless information etc… all free with a small shipping and handling charge, which somehow is not counted as a cost? I was listening to that radio station while hopefully administering the drain product according to the directions, which then always seems to digress into pouring the entire contents of the gallon jug down the drain. I was inspired by the incessant radio commercials to get back at the world; I would be sure to follow up on this product’s claims. The drain service I then called was prompt, clean and got the job done. The liquid drain product didn’t work… the refund form is in the mail.

Speaking of refunds, I bought a refrigerator online this last week and the Labor Day sale included free delivery. The delivery charge was listed on the shopping cart pre-total screen, but the amount was then omitted from the final total ordering screen and I confidently made the purchase with free delivery after adding all the numbers.

Ahh, but the plot thickens… I got my receipt via email some time later. The delivery charge was added back to the total!!! (I think this is illegal). This was a MAJOR retailer. I called customer service and asked them to explain. This person seemed to be filling-in for someone else and was clearly sorry she had answered the phone. She was able to tell me that the free delivery offer was by rebate, but didn’t know what a URL was and when I baulked at her suggestion to go to //Rebates.com she told me she would just email me the form and hung up. Going back to the retailer’s ordering website I did find a 6pt font link to more details under the 50pt font claiming free delivery. The link explained the detail of the offer, but no link helped me locate the actual rebate form. So, I Googled it.

The refrigerator was delivered, but still no rebate form.

Another call to support… this service person was all business.

Yes, …rebate form, …no problem. …I just emailed it to you, anything else… Okay bye.

I open the ensuing email attachment and the form was for a rebate of postage for purchases made before August 2005!!! Another call to the service number… this person claimed she couldn’t help me and that rebates were a different department with a different 800 number. I, like a fool, dialed it… I kid you not, a fax machine answered…. I am a little less happy now. Another call to the service number; I was quiet, calm and deliberate when the customer service guy answered the call. I warned him I was grumpy and that I was challenging him to provide useful service, before giving him a brief review of the service I had had so far. He pointed me confidently to the rebate forms section of their website (someplace I’ve already been thanks to Google) and begins to ask me if there is anything else he can help me with. I ask him to tell me which form of the 18 different forms I am supposed to use. His confidence waned… none of the descriptions of the forms fits the description of my purchase…

Can I put you on hold? is his response. Long pause….
Uhh, how about number 3?
No, I quickly reply that form is for dishwashers, I bought a refrigerator.
Oh, can I put you on hold again?, is his retort. Longer pause…
Ok, (confidently) it is number 1. Try number one, he suggests as he attempts to close the call again.
...Wait, I suggest politely. I want to read it.

The description for the form’s link says it is for a different brand than I purchased, but he convinces me the link was mislabeled and that the actual form is for any appliance not just the brand listed in the link description. I reluctantly end the call. I guess you'll have to wait 6-8 weeks to hear the conclusion.

I took my wife to a restaurant this weekend. We were given a gift certificate for that restaurant and we had a fine meal. My wife ordered the special and when processing the check the server returned to our table informing us that the owner said we could not use the gift certificate with the special. After thinking very carefully what I might say next, to avoid ruining an otherwise pleasant evening with my wife, I suggested to the server that a gift certificate is not a coupon, but rather just like cash. She sheepishly returned to the owner who then processed the check herself. The owner walked to our table to return our finished check and wanted to express in person how gracious SHE WAS for accepting the gift certificate under these circumstances! The exchange with her was so surprising… so NOT RIGHT, I was actually amused to receive such bad service from the owner herself. If you ever get a chance to visit Balboa Island in Southern California, might I suggest you try Ciao’s italian restaurant two doors down, instead.

Last week I also took an ESRI class on ArcGIS Server where I learned more about ArcGIS Server. From what I understood, ArcGIS Server creates different types of services that various software clients can use. There are Map Services (which display maps and allows me to query the underlying data), 3D Globe Services (3D Maps like Google Earth), Geodata Services (special access to the data over the web), Geoprocessing Services(predefined GIS tools), Metadata Services (access to catalogs of content), WMS Services(OGC standard published maps), WFS Services (OGC standard published map features) and Locator Services (Geocoding and Routing for GIS networks). Most of these services interoperate with CAD by the simple fact that ArcGIS Server uses CAD files as a valid GIS data source content for the services. The geoprocessing (GP) services work both with CAD data as input to many GP tools as well as potential output. I can include the GP tool EXPORT TO CAD to generate CAD files as a part of a GP Service task.

ArcGIS Server interacts with tools that communicate with the internet to provide sophisticated GIS services through simple protocols for software applications to use over the intra/internet. I use ArcGIS desktop tools to author content, like 3D globes, or map documents or geoprocessing tools and then publish them to ArcGIS server that pushes them out efficiently and securely to the network for client applications to connect to and use.

The ArcGIS Server map service is special in terms of CAD. In addition to the capability of including CAD data in an ArcGIS Server map service (along with all different kinds of other GIS data) I can also view map services in plain AutoCAD with the no-cost ArcGIS for AutoCAD application. This type of service gives me a window into the GIS world in CAD and I see what the GIS people see.

The no-cost ArcGIS Explorer mapping client software gives me access to even more services. Publishing CAD content as part of my ArcGIS Server Map service allows me to easily distribute GIS and CAD content together in a published map. Geoprocessing services that provide sophisticated query and analysis capabilities can also be utilized from the no cost ArcExplorer application. GP services can also be accessed by custom web applications.

I use the ArcGIS Server Manger to build custom web applications (in seconds). I click through a wizard and include the services I want from simple checkboxes that then creates the HTML application on server that is accessible to the intra/internet. These wizard-generated applications support most of the different kinds of GIS Services that ArcGIS Server can serve out (with the exception of geodata services, which are designed for desktop applications to access the underlying data of a service.)

GIS Services are created for all different reasons by content publishers and are accessed by many more users interested in that content, generally with no-cost applications. If I am an engineering contractor with plain AutoCAD and the City has published ArcGIS map services for public access then I can connect to those services and see and query those map services via a simple web application, or perhaps more usefully in AutoCAD with ArcGIS for AutoCAD.

ArcSDE CAD Client for ArcGIS 9.2

2007-08-13T15:36:00.000-07:00

Last week I took our family to the circus. Everyone should get a chance to take a three year old to the circus. My younger daughter sat on my lap a little apprehensive about the whole scene. She was a little overwhelmed with the three rings of activity. However when the tigers started hoping around and rolling over she thrust her hands up into the air and burst into spontaneous applause! …Searching for the eyes of her mother to share her excitement.

With similar excitement those of you who were looking for ArcSDE CAD Client for ArcGIS 9.2 you can find it on the ESRI Support Download pages.

ArcGIS for AutoCAD User Forum

2007-07-30T15:22:00.000-07:00

My printer at home was on the blink. It continuously had been reporting paper jams and then systematically jamming more paper during printing. Each time I cleared the paper jam another would re-occur. I surmised that one of the rollers was broken or malfunctioning. I suspected it was some broken $0.30 plastic part that would render the entire printer useless. Facing the high probability of adding this printer/scanner/copier to the growing enormity of e-waste, I was dedicated to giving the printer one more vigorous going over. Figuring that some poking and prodding in places where fingers should not normally go couldn’t do any more harm to the printer than its final drop into the recycle bin. I picked up the printer firmly to eye-level to see what I could see, which was nothing. However, the act of picking up the printer opened the clamshell like access to its internal parts changing its center of gravity and then the entire printer spun out of my hands and onto the floor! As it hit the ground a small wad of paper lodged somewhere in the printer’s innards was forcibly ejected. ...It was actually a little surreal.

The printer successfully passed the 1 meter drop test and is now functioning normally, postponing its trip to the recycler thanks to this computer peripheral version of the Heimlich maneuver. I suggest that you should consult your printer’s service manual before attempting to duplicate this procedure.

By the way, you may have noticed ESRI has added a user support forum for ArcGIS for AutoCAD users.

The View from ArcGIS for AutoCAD

2007-07-13T16:11:00.001-07:00

I just got back from camping on a lake that you can’t swim in. In some ways it is a form of torture… on a hot summer day being so close to the water and not being able to jump in. The water in the reservoir can touch you, but you can’t touch the reservoir. We enjoyed canoeing on the reservoir, and with a little extra paddle splashing we managed to keep sufficiently cool in the summer sun. Still, I am wondering what problems are added to the domestic water supply with the advent of swimming in a lake that a rotting dear carcass, an active coyote population, and motor boat oil don’t already present? As a former Civil Engineering student I guess I should have paid more attention during the chapter on water treatment.

The no-cost downloadable ArcGIS for AutoCAD software currently provides me with an image drawn by ArcGIS Server, positioned accurately in my AutoCAD drawing. I can’t actually touch the GIS data from within AutoCAD, but I can see and plot the resulting image drawn by ArcGIS Server in AutoCAD. ArcGIS Server can touch me in AutoCAD with a world-class cartographic view of the reservoir of data along with access to the data’s tabular attributes (wherever they might be stored, I don't care since ArcGIS Server knows). The biggest benefit is the content of the map that gets drawn and the functionality of the application used to generate the image; namely ArcGIS Sever. All GIS data types supported by ArcGIS Server are now available to me in AutoCAD. All worries of mapping symbology and data access evaporate. I get the benefit and keep my cool doing it.

Our next camping trip is planned for the beach… right on the sand. We’ll have the entire Ocean right in front of us, and we plan to jump in!

ESRI 2007 International Users Conference

2007-07-03T10:38:00.000-07:00

The planning for this summer’s event began months ago. In the limited time allotted there are many training and skill building opportunities that are shared. We all have to make tough choices about what we put into the schedule and after it is all over what we hope to accomplish from attending. Of course I’m talking about our high school girls summer basketball camp. Coming off an undefeated season, and capturing the 9th grade homeschool state basketball championship we’ve tasked ourselves this summer with taking our game to the next level in pursuit of a national championship. A lofty goal, especially considering many of our girls have very limited experience despite their unparalleled efforts and teach-ability. Unlike the season's basketball practices, the weekly one night a week format of basketball summer camp is hard work, but it is also fun. We started with a core group of girls, but word soon spread and we’ve almost doubled that number because the girls are having so much fun. They don’t realize how much work they are actually doing.

Also occurring last week was the 2007 ESRI International Users’ conference. I’m am not sure if it is true, but I heard that the event in San Diego is one of the largest single software meetings in the world with almost 14,000 people gathering in an atmosphere of fun and learning. As always I had a chance to meet with many of you and discuss your work, and you had the opportunity to experience a little of what I do when I’m not blogging. Thanks for sharing your work with me as well as your encouraging comments in person.

One GIS and CAD interoperability technology development that was unveiled during the conference was the description and demonstration of enhancements to the ArcGIS for AutoCAD application. Demonstrations included a new method of defining the coordinate system for a CAD file that is stored inside the AutoCAD drawings, and using that coordinate system information (projection information) to project ArcGIS Map Services on-the-fly for maps that may be maintained in a different coordinate system.

Also shown was a subtle but important new piece of GIS and CAD interoperability technology; a new AutoCAD-based feature class data encoding technique and specification. The new specification doesn’t require any add-on Autodesk or ESRI software inside AutoCAD. It is based on the entity filter syntax of existing AutoCAD named selection sets and includes some simple text strings stored in AutoCAD ‘X’-records to denote the type and contents of a user defined CAD feature class. The resulting feature class definition functions like a definition query in ArcMap, but instead of being set by the GIS professional after she receives an AutoCAD drawing, I as the CAD user define the correct feature class definitions based on my knowledge of the CAD file and how it can best be understood in the GIS.

Future versions of ArcGIS will recognize and honor the CAD feature classes along with the standard POINT, POLYLINE, POLYGON, MULTIPATCH and ANNOTATION feature classes of a CAD file. ArcGIS for AutoCAD will include tools to create and manage these feature class definitions, but CAD users can easily create and edit them using the simple AutoCAD application programming interfaces (API’s), as long as they adhere to the simple specification. These CAD feature classes will in turn be recognized by ArcGIS. More to come on this …

Significantly Insignificant Digits

2007-06-07T13:59:00.001-07:00

I design sailboats as a hobby. One of my friends designs flying disks, ornithopters, boats, gliding toys and UAV’s for a living. He shared with me recently regarding some proposed changes I was contemplating in my boat design with advice:

There are certain designs changes that you can implement that make a big difference in how something will move through the air or water. Often times there are orders of magnitude difference between the primary and secondary
factors.

It has been my experience agonizing over small changes in the design phase of my boat can become the proverbial case of straining a gnat and swallowing a camel… or, being pennywise and pound foolish.

How much precision is needed to store accurate engineering data? Older versions of CAD and GIS software used a long integer with an offset value to store very large coordinates with very small difference between those coordinates. ESRI 3D Shapefiles, 3D File-based Geodatabases and AutoCAD drawings store coordinates using what equates to essentially double precision numbers. Double precision numbers allow you to store very big numbers with very small differences between the numbers. The new ArcGIS 9.2 ArcSDE technology can store larger numbers than ever before with smaller differences between those numbers. A worth while question is how big or small do these numbers need to be to accurately store objects on our globe…should they support infinitely big and infinitesimally small numbers?

The pessimist says; The cup is half empty. The optimist says; The cup is half full. The engineer says; The cup is TWICE AS BIG as it NEEDS to be!

I was a bridge inspector for a summer, and got to crawl over all different kinds of bridges in Washington State overlooking some pretty scenic places. I reported on the safety conditions and maintenance issues of the structures. One could ask, what would be the safest design for a bridge? The answer I got from one engineer was to fill the valley with concrete; that would be the safest bridge. However, I doubt the bridge engineer would win a design award for such a bridge. Using the high precision geodatabase available in ArcGIS 9.2 and given 40 million meters are the equatorial circumference, you can map to the nearest 4 nanometers. A micron or micrometer is one millionth of a meter. A nanometer is one billionth of a meter.

Relating these sizes to the real world; a human hair is said to be about 50 micrometers wide. Viruses range in size from 20 to 250 nanometers., clay dust particles have diameters less than 2 microns, silt particles range from 2 to 50 microns, and sand-size particles are greater than 75 microns. So as I understand it, you could map viruses on the dust, from the sand, over the entire surface of the globe!?

If you are concerned about the accuracy of your data, likely the precision of the number stored in AutoCAD, Microstation, ESRI Shapefiles or ArcGIS isn’t where you should focus your attention. For more information regarding the intimacies of coordinate data storage for Geographic Information a new white paper on the subject from ESRI.

I'm thirsty I think I'll get a half cup of water...

There are some who call me…BIM

2007-05-22T14:10:00.001-07:00

Arthur: What manner of man are you that you can summon up fire without flint or tinder?
Tim: I... am an enchanter.
Arthur: By what name are you known?

Tim: There are some who call me... 'Tim'
Arthur: ... greeting, Tim the Enchanter.

-Monty Python and the Holy Grail

I attended the National BIM conference in Anaheim last week. The conference was attended primarily by Architects and Builders looking for ways to both earn continuing education credits and for a means to gain advantage in the marketplace. Or, perhaps attendees, like me, wanted to make sure they were not missing the BIM boat. Every session started with a definition of BIM, and for good reason. I am as sure as ever that there are competing movements all riding the buzz-word status of the BIM label. In the current state of BIM all definitions are valid since no one definition has gained “ownership” of the term. There does seem to be some consensus that Autodesk marketing coined the term, but it has long since outgrown the bounds of any one software vendor’s brochure.

It is my perception that there are three major movements still vying for the mindshare of BIM. First are the architectural CAD software vendors who are attempting to differentiate their tools one from another. The message is, “… our software is more than just a drafting package, but rather an information system for the planning, design, performance and operation of a building.” To this end BIM exists today and depending on the various vendor claims has existed for as many as 15 years. To these software vendors and cutting edge design firms the key is the adoption of the smart 3D building models in their design and construction business practices, and workflows.

The second angle comes from the big owner-operators (government) who see BIM as the answer to a long standing facilities management problem. This is a problem that is accentuated by the perceived need to improve emergency response capabilities, and to improve environmental and fiscal responsibility. They see BIM as a repository for all the useful information assembled at the time of planning, design and construction that is lost to the owner of the building once they take possession of it. The idea is that such design and construction information can reduce operating costs and prolong the life of a building through intellegent management and a better understanding of its history. They would then like to add information collected during occupancy that both leverages and adds to the information model. The fact that a BIM is 3D makes the inferred uses and value potential that much the more compelling. For them the key is the magic model that when defined properly will codify digitally the useful reality of a building and facilitate the answers to useful questions.

The third movement involves a combination of the two (based on one and enabeling the second), and has as its foundation the notion of interoperability and information access. In this camp are government agencies, trade assocciations, standards committees and research groups. Their aim is to make the information of a digital representation of a building usable for query, display and analysis independent of any specific application, business process, discipline, or software vendor. Their goal is the qualification and access of information pertaining to and about buildings. In the interoperability and standards view of BIM the information transfer means is the key. Neutral access to information is more important than the tools to construct, store or manage the data. For them a neutral file format and a list of minimum content requirements is the key to meaningful BIM. Their hope is that when successfully implemented their work will be used as the gateway to other information systems like GIS.

Live GIS/CAD Training Class

2007-04-25T15:48:00.000-07:00

I took my girls camping this weekend near Ojai. On the way up we ran into a Ferrari club touring by. The freshly paved winding road was an idyllic setting for these rolling art pieces. We saw about 20 different vehicles all with the same rearing stallion logo. Some of them I recognized some new one’s I hadn’t seen, and a there were a couple of vintage classics. In the middle of the parade of Ferraris was a splash of realism, a circa 1975 brown GMC full-sized van… I must say a van never looked so, well… brown.

ESRI is putting on a Live Training Session for CAD use in ArcGIS tomorrow. Come see some things you might recognize, something new and some classics. Like all ESRI Live Training Sessions this one will be recorded and made free for viewing in a couple of weeks in case you miss it, or want to view it again later.

PS. The recorded session is now availble.

ArcGIS for AutoCAD a Sea of Possibilities

2007-04-16T11:59:00.000-07:00

View of our Earth centered roughly on the South Pacific

I am haunted by a few nautical images that I have seen in movies; seascapes in Master and Commander, and the old version Moby Dick, (with Gregory Peck as Captain Ahab, chasing the great white whale around the globe) are two that rush to mind. Also there is a line from Disney’s Pirates of the Caribbean where Captn’ Jack Sparrow is waxing poetic about what a ship is.

“That's what a ship is, you know. It's not just a keel and a hull and a deck and sails, that's what a ship needs, but what a ship is... what the Black Pearl really is... is freedom.”

My reaction to these tells me that in another time, I may have been lured to a life on the sea (when the occupation of GIS/CAD professional was not so viable). To me there is something compelling about the geography of the globe that can be traveled by the Oceans and although it is a unpredictable and ominous path, it connects the whole world.

Here is a link to a recent interview for GIS Weekly I gave regarding the newly released ArcGIS for AutoCAD: “What Do CAD Users Want to Do With GIS?"

Working with Text: Part 3

2007-03-28T14:58:00.000-07:00

The ArcGIS Import CAD Annotation Tool

Spirit Academy’s Lady Warriors enter the California State tournament with an undefeated record of 17-0 in the regular season. A team invited from neighboring Arizona will be their first contest in a seeding game. The seeding game will determine how the teams stack up in the grid going into the tournament. The visiting Arizona team has no game history with the California teams in the tournament, and so there is no frame of reference for how they match up. After they play us the tournament committee will size them up and output the final brackets.

Just like the visiting Arizona team, there is no frame of reference for how CAD text should be displayed in the map-centric scale-dependent environment for which ArcGIS annotation was developed. CAD text traditionally has one size defined in drawing units. Annotation on the other hand has a scale dependent size defined usually in POINTS.

In order to size up the CAD text for display in ArcGIS as geodatabase annotation you need to supply reference scale and a size for that scale. The Import CAD annotation tools prompts for these two values. I have created a sample tool available on ESRI's ArcScripts.ESRI.com that helps you understand and calculate the appropriate values to enter into the Import CAD Annotation tool. You might also benefit from a more technical description found in the online help.

Go Warriors!

Working with Text: Part 2

2007-03-14T15:45:00.000-07:00

ArcGIS Labels and Annotation

I really enjoy the way a small sailboat has gives me a feeling of being directly connected to the water, the air and the craft itself. More than just floating or paddling through the water, a sailboat allows me to use natural forces against one another for my gain. I can float if I want to, but generally I want to be going places.

In ArcGIS text can just float on its own, or it can be driven by features. In the most general terms GIS annotation could include any map text, marginalia, and displayed attributes. More explicitly there are different forms of text in ArcGIS using different data constructs. Any ArcGIS feature can have feature labels that are generated from attributes. Unlike ArcGIS feature labels ArcGIS annotation features are features in their own right. One higher level of annotation is that geometric features can have annotation features that belong to them, this is called feature-linked annotation. Or, text can be displayed as simple graphic text, that is not a feature, and not linked to other features, this form is the most similar to CAD text.

In ArcMap any GIS feature can have a displayed feature label. This feature labels can be toggled on an off as a property of the ArcMap label. The label can have justification and font properties and its text value is derived from the attributes of the feature layer. Labels are regenerated from the feature's attributes and generally are placed by a labeling engine. The default labeling engine has some simple options to avoid overlapping labels and the alike. An example of a high-end professional labeling engine would be something like ArcGIS’s Maplex labeling extension that uses sophisticated rules-based label placement algorithms. ArcGIS feature labels can be converted into ArcGIS annotation feature classes.

Another form of text, ArcGIS geodatabase annotation feature classes, have their own geometry, attributes and set of justification methods. Unlike feature labels that are placed on-the-fly using an engine from other feature layers’ attributes. Annotation features are persisted and stored in a feature class, along with their position and other display properties. Annotation features can be independent or they can be linked to other feature layers. Feature-inked Annotation derives its text value from the attributes of the linked feature class (like the diameter of a pipe, or name of a street), but retains its own separate geometry and properties (for example: a specific rotation or position on a map.)

You can learn more about ArcGIS text from the ArcGIS online help.

Tip:
ArcGIS feature labels cannot be exported using for example the Export to CAD tool, but the tool does export geodatabase annotation features, which I can generate from feature labels in ArcMap.

The ArcGIS CAD feature class that is generated in memory when a CAD file is used by ArcGIS, is yet another form of text. The CAD annotation feature class is implemented as a file-based
annotation. This type of annotation is more akin to the legacy ArcInfo Coverage Annotation feature classes. Suffice to say it is old-school and lacks many of the nifty functionality available with the invent of geodatabase annotation feature classes.

There is a tool to convert file-based annotation and CAD annotation feature classes to geodatabase style annotation. This tool is called the Import CAD Annotation tool…

ArcGIS for AutoCAD

2007-03-05T09:26:00.000-08:00

I’ve been anxiously awaiting this debut, we’ve done a lot of work and we are well prepared. The Head Coach has a schedule conflict and has given me (the assistant coach) the nod to take the head coaching roll of our undefeated high school girl’s freshman basketball team for their next game. It is one thing to make suggestions as an assistant coach, it’s quite another to make the decisions at game time and be responsible for them. I am excited to get the opportunity, and give it a try.

Here is something else new to try… as seen at the ESRI Federal User Group Conference in Washington DC this past December, the ArcGIS for AutoCAD application from ESRI is now available for download just incase you missed the ArcNews Article.

ArcGIS for AutoCAD is a no-cost ESRI application that loads on top of AutoCAD 2007 and gives me the ability to add one or more ESRI Map Service view(s) to my AutoCAD drafting environment. The coordinates of the ArcGIS Map Service and the AutoCAD view are fused together. With this new ESRI technology I have direct access to every GIS data format without conversion and without translation inside AutoCAD through ArcGIS Server. I as an AutoCAD user see what the GIS professional sees; finished high quality cartographic representations of complex GIS data structures, stored in a wide variety of different, raster, grid, image and vector formats. I see the results of high-end cartography and sophisticated spatial analysis as represented by the finished map, served with ArcGIS server. Arguably I get the most benefit… the results, without ever having to concern myself with what data types I am working with, where the data is stored or how I should display the map content. I can work directly with ArcGIS Map Services to add full GIS context to my AutoCAD session.

ArcGIS for AutoCAD introduces a new form of CAD Interoperability, by passing GIS right through CAD rather than relying on special data connections, translation or conversion. I need not concern myself with what GIS data types I can or cannot read in AutoCAD. I need not worry about setting up ways to recreate the symbology of GIS Maps. I see the GIS map as created by the GIS professional. I have direct access to the attribute records stored in the spatial databases where ever they may be stored. The GIS functionality is simply passed back and forth between the GIS server from requests I make in CAD. You can download the software from ESRI here. It requires access to ArcGIS Server 9.2 map services and AutoCAD 2007.

Working with Text: Part 1

2007-03-02T14:26:00.000-08:00

CAD Text

You may have heard it said that a boat is a hole in the ocean that you pour all your money into. I am of a small minority of people that can be pitied even by the average boat owner. I have a hobby of boat designing/building. At least with the normal boat owner, the boat does, or did at one time function as a boat, and with a little effort and maintenance will continue to function as such. However, I on-the-other-hand pour my money, and efforts into a boat that I spend 6 months constructing, sail for 40 minutes and then hack into pieces and rebuild for another 6 months. Sad if I think about it… I will think of something happier... like ArcGIS annotation! On second thought the hole in the ocean may be less dreary; too late I’m committed now.

Arguably one of the more confusing aspects of CAD interoperability in ArcGIS is the way text is handled. I get lots of questions related to the different ways text can be created, displayed, oriented and converted between CAD and GIS. This is compounded by the fact that CAD text is quite different than the various forms of ArcGIS annotation.

I guess its worthwhile defining some terms/concepts used by these two different technologies before I tackle some of the confusions caused primarily by these differences. Looks like another BLOG series…

CAD text is stored as an entity that has an insertion point, a text string and a number of text properties. These text properties are slightly different between AutoCAD and Microstation, but in contrast to GIS they are not really worth mentioning. One of the distinguishing properties of CAD TEXT is a text height. TEXT in CAD has a size in drawing units (unlike ArcGIS annotation). When you zoom in or out it is like any other object you see more or less of the same objects; closer or farther away; bigger or smaller. CAD text is an autonomous object that lives on its own… it is a TEXT object.

Another type of object printed on a CAD drawing could be AutoCAD block attribute or a Microstation tag. These objects unlike CAD Text entities are normally associated with something else. In the case of the AutoCAD block attributes they belong to an instance of an AutoCAD block, as a sub-entity of the block insert. To confuse the issue AutoCAD blocks instances (inserts) can contain actual text objects as sub-entities too. However, the block attribute is like a variable whose text string you can modify. The block attribute has a logical name. Because of this ArcGIS treats the block attribute like a feature attribute in ArcGIS CAD feature classes (But, that’s another topic.). In ArcGIS 9.2 block attributes are also considered an ArcGIS CAD Annotation feature and have their own insertion point and text properties, just like CAD text.

Microstation has a similar, but more powerful object called an element tag. A tag is an object that similar to a piece of text has size, font and justification properties. Similar to the AutoCAD block attributes it can be associated with another gemetric object. It also has a logical name and its text string can be modified as a variable or attribute in CAD. Different than the AutoCAD block attribute Microstation tags can belong to any other Microstation element geometry, including polygons and linear features (AutoCAD block attributes are really only associated with what could be interpreted as point features). In ArcGIS 9.2 Microstation tag elements are represented both as attributes of the CAD features they are associated with and as independent ArcGIS CAD annotation features.

Next, I’ll discuss a little more about the ArcGIS flipside…

Create Features From CAD Layers or Color...etc

2007-02-14T15:33:00.000-08:00

I am just now getting back into the swing of things after the big super sports weekend. I lost my voice cheering for my team, and then caught a nasty cold. I am happy to say my team was victorious; Yes in all three games. Of course I am talking about high school girl’s basketball. We had three games in 18 hours. Our record is now 10-0. Our girls have a feisty full court and half court trapping press.

The head coach and I both have daughters on the team and we still sometimes struggle to figure out what ultimately motivates our girls, different from boys who seem to have a more natural fighting instinct. From time to time we inadvertently use jargon that doesn’t translate into a girl’s world. One time during a game the coach was hoping to get some more inspiring effort from the team. He looked down the bench at the girls and exclaimed, “WHO’S HUNGRY!?”, and then quickly focused his attention back to the game in progress. I was left to field the puzzled responses from the players sitting next to me. One said quietly, “ No, I’ve got my chocolate milk (holding up the container for me to see).” Another said, “no, I already ate.” And, a third asked, “What does he got?”

The term LAYER has a different meaning in the CAD and GIS worlds. I’ve written before how CAD layers are similar but very different from GIS layers, both in how they are used and how the data is stored. In CAD a layer is a graphic property, like entity COLOR, or entity line type. CAD does treat the layer property in a special way in that visibility can be controlled by the LAYER property. But, in every other way the LAYER property is like any other CAD graphic property. The choice to organize a CAD drawing by the LAYER property is arbitrary, and often CAD drawings are organized by combinations of other properties such as entity TYPE or COLOR in addition to the layer property.

In ArcGIS a GIS layer is used as a logical name for a group of features in a map or geoprocessing operation. A layer can denote a selection set of similar features; it may include joined tables, and may also include information on how the features are to be displayed. It is often convenient to talk about a GIS layer as synonymous to a GIS feature class, but generally a layer is build from a feature class.

When CAD data is organized more or less by CAD layers a sample geoprocessing script tool like SplitByColumn can make use of the CAD Layer property of a CAD file to automate the task of converting a CAD file with data on various layers to ArcGIS feature classes based on those CAD layer properties. This general use tool will take as input any feature class and split it into multiple feature classes based on unique values that appear in a given column.

Here is an updated version of the SplitByColumn tool for ArcGIS 9.2. There is a similar tool in the CAD Sample Toolbox for ArcGIS 9.1. Changes were made to the script so that it doesn’t require Python Win and a change was made in the ways string values are recognized in columns. You can download this new version of the sample tool on ArcScripts.

The Universal CAD Projection File

2007-01-22T15:48:00.000-08:00

My daughter’s basketball team that I help coach is off to a great start. In two freshman contests we are 2-0. These same players with Elise forming our Junior Varsity team, won their first game against a Varsity opponent.

With our small school team we use the same coaches, essentially the same players and the same offense and defense playbook for two teams. We position the players and their rolls on the floor using just the one set of instructions.

In ArcGIS 9.2 you can use a single ArcGIS projection file to describe the spatial reference for an entire workspace of CAD drawings. By naming an ArcGIS projection file with the name esri_cad.prj all of the CAD files in that workspace that do not have their own projection file will use that file’s instructions to identify the coordinate system of the included CAD drawings. Therefore if you have a directory full of tiled CAD drawings you need only define the coordinate system once for the whole set. Be sure however that if you move a file out of that directory that you also make a copy of the projection file specifically for that drawing.

Coming up on the basketball schedule will be a weekend with 3 games in 18 hours…, Go Lady Warriors!

From the ArcGIS 9.2 Help System:

Tip

The universal projection file is for defining a coordinate system for all CAD drawings in a workspace. esri_cad.prj will apply to all CAD drawings in that folder, which do not already have a projection file designated. If one exists for a specific file it will override the esri_cad.prj file.

Walls or Checkpoints of Interoperability?

2007-01-19T14:58:00.000-08:00

This week we celebrated Martin Luther King day. In retrospect I think what I did over the weekend may have been very appropriate. I tore out a wall in my house. The wall between the kitchen and the dinning room is now a stack of rubble in a rental dumpster at the curb. We don’t really use our formal dining room for formal dining. It makes more sense for our lifestyle to have an open floor plan. We want to see into the other room while we’re cooking and freely move between the rooms. Instead of walking back and forth round the wall or passing things through the wall. Our solution was to just get rid of the wall all together. In our case the wall was a “non-bearing” wall. A structural engineer gave me the assurance that its absence would not affect the stability of the structure. One of our neighbors with the same floor plan had removed the same wall several years ago, which gave me even more confidence to take sledge hammer in hand.

The walls between GIS and CAD can be workflow, data structures, job descriptions and sometimes tradition. Removing walls can generally be considered a good thing. However, Sometimes walls are there for good reasons. Security, data ownership and quality are some good reasons for maintaining business practices that establish formal segmented workflows as safeguards. Rather than walls they may be considered checkpoints... (basemap extraction for context, data standards for design and attribution, translation for interpretation, and spatial analysis for QA/QC.) It is still important that data flow smoothly through the checkpoints without delays of ambiguity, inconsistency or incompatibility. However it is not always necessary or even desirable for everyone to have access to edit all the data in an enterprise, whether it is CAD or GIS-centric data.

Often in my work I strive to break down walls and give people more control and access of their data that is in both GIS and CAD formats. I think it is good from time to time to consider that many interoperability workflows function just fine with read/only access or one-way conversion. Breaking down walls can be the right thing, but sometimes I can accomplish the desired task by putting in a window, or a door that I can lock from the inside or the outside.

Holiday Sound Bites and Blog Comments

2007-01-03T12:54:00.000-08:00

Happy New Year. Before Christmas I was practicing for an important technical presentation the night before I was going to present, and my wife volunteered to be the practice audience. My wife is a gifted piano teacher, but has only just recently been introduced to the internet. She listened to my highly technical presentation and upon its conclusion with a smile commented softly that it was better than a bed time story. I was encouraged, thinking I had done a good job communicating the complex topic in a clear way… Then I thought strange choice of words. I asked. “ Why was it better than a bedtime story?” Her response, “Because now I’m really sleepy… goodnight.”

I wear glasses to read my computer screen, but don’t generally wear them for daily living. I left them on one day and drove home. My daughter greeted me at the door and said, “Hi dad. You look smart (long pause)…well smarter.” I guess I will have to believe that during the pause she was considering that she may have inadvertently implied I didn’t always look smart, or perhaps I wasn’t really smart at all, and was compelled to add to her initial comment.

With my wife being a piano teacher with lots of thankful students, and being surrounded by many friendly baking neighbors we amassed quite and impressive quantity of Christmas treats as gifts these last few weeks. We have a young single neighbor who I thought might like to benefit from some of our excess. I asked him, how do you feel about apple pie? His completely straight faced soul searching response, “Well… I feel pretty good about it.”

Thanks for all of your encouraging comments you’ve shared with me regarding this blog over the last year. I hope to keep supplying useful content that you can feel good about. I hope to continue to add to its value. Don't forget to visit this blog's archives and share it with coworkers as a growing reference resource. I will continue to update and improve the indexing.

The Mysteries of AutoCAD Object Data: Part 3

2006-12-18T12:41:00.000-08:00

Custom Objects

My talented neighbors have recently finished another amazing automotive restoration. This one is a 70’s era pickup truck. Before the restoration the pickup wasn’t much to look at, and it left me thinking, why invest any time or money on this hunk of junk. The artistic eye of this teenage boy saw something more… a dream machine in the rough! And, possibly his choice may have had something to do with the fact that he had to buy the car himself. I think the original plan was that the son would work at his restaurant job and save the money to buy the necessary parts and materials… That lasted about a week and then dad couldn’t help himself. Now with a better bank roll… off came the paint, upholstery, the doors, bumpers, the truck bed, some of the side panels, the engine, the wheels… Many of these items would never return. It got to the point that so many parts we’re completely replaced and meticulously reworked that it would seem to me that it would have been certainly easier, and even cost effective to just open up the catalog and order an entire truck from parts and have UPS ship it to the garage for assembly! At one point the son and his sister’s boyfriend were just hanging-out on the front step scrubbing a bucket full of rusty bolts all day long.

Autodesk Map 3D is a collection add-on customization code to extend the data structures of the basic CAD data model of AutoCAD to support the attribution of its geometric primitives for use in mapping. Autodesk 3D Civil is the same type of application to extend AutoCAD for Civil Engineering. Their primary method of attribute storage is object data. Autodesk Map/Civil 3D cannot function solely with standard CAD graphic entities. They introduces more sophisticated GIS data structures in the form of AutoCAD custom objects.

The definitions of the AutoCAD custom objects are stored in the AutoCAD data dictionary like object data, in some ways these custom objects are like a block definition that is stored in the AutoCAD symbol tables. However like the x-records used to store object data the custom objects and their complex geometries are not discernable without the controlling application that created them. To manipulate these custom objects AutoCAD must be re-educated on how draw and manipulate these foreign data structures. It is the responsibility of the controlling application to instruct AutoCAD what the various methods and properties are that will be supported by the custom object.

Neither AutoCAD nor LT can understand these objects. Read/Only versions of certain applications called object enablers can be obtained by AutoCAD users to understand these complex objects and sometimes their attribute data. The other method of making a custom object more readable to applications like AutoCAD and AutoCAD LT is for the custom application to create a proxy geometry definition along with the custom object. ArcGIS 9.2 now reads proxy geometries of AutoCAD custom objects as GIS features. A proxy geometry may be a pretty good representation of the original geometry, without its clever behaviors and attribution or it may be something less than that, all depending on the application that defines it.

The Mysteries of AutoCAD Object Data: Part 2

2006-12-08T11:00:00.000-08:00

Für Elise

My wife’s piano students had their Christmas recital this past weekend, and they were all splendid. Briana played Beethoven’s Fur Elise, but that is not my story at all. My daughter’s basketball team at her tiny school is gearing up for the basketball season and after the initial recruiting effort here is how it stacks up. Remembering this is a ninth grade team, we have three ninth graders, four eight graders, five seventh graders and one eleventh grader?!

…The problem is the eleventh grader, Elise. She is six foot tall and played point guard last year on the varsity team. The rest of last year’s varsity team were all 12th graders and they are gone. Remembering this school is tiny, Elise is the lone basketball player older than ninth grade. The solution… form two teams; a ninth grade team where most of the girls are already too young to play, and another team with the same girls and Elise to play varsity! I am just the assistant coach and I guess I must share in the blame for not saying no, but I guess it’s Für Elise!

Sometimes you work with what you’ve got, and object data is the right thing to use when attributing objects in the Autodesk infrastructure ad-on products to AutoCAD, I don’t have a choice. Problems only arises when I need to move the data into GIS. The first and most logical path for moving data with its attributes is to simply use the Map 3D function to convert the data to an ESRI Shapefile. You’re done... happy day.

…Ahhh, then there is the unfortunate fact that the double precision 3D ESRI Shapefile doesn’t support curves. The 3D double precision ESRI personal geodatabase does support curves and splines. For Autodesk Map users there is a new FDO plug-in for ESRI personal geodatabases. I am a strong proponent of the benefits of editing GIS data with a GIS application, with this Autodesk Map FDO provider, you can directly view features from an ESRI personal geodatabase using your existing seat of Autodesk Map, I have no idea if it works and not everything in the personal geodatabase is supported, but it sounds pretty cool.

Another method to retain both the attributes and curvilinear data not supported by a 3D ESRI Shapefile is to export the object data attributes and link them back up in the to the CAD entities in ArcGIS. I need to export the object data into some industry standard data format such as .dbf file or a text file or some other standard database-like format. I will want to ensure that included with a dump of the proprietary object data attributes that there is some key field upon which I can re-link the data once I am in a GIS. I will be able to perform a table join directly on the CAD data without converting the data or after I convert it if needed.

Another trick to get object data with curvilinear geometry is to create a Shapefile and only use the attribute table part. With ArcGIS, read the AutoCAD file directly, the AutoCAD entity handles will still be in the original drawing. Make sure the entity handle property is included in the output Shapefile’s attribute table. I can then ignore the geometry part of the Shapefile and link the AutoCAD file with the curvilinear data directly within ArcGIS to the .dbf part of the matching Shapefile’s attribute table. (This only works when I am working with Object Data on real AutoCAD entities rather than custom entities. …More about custom AutoCAD geometry later)

I can create my own AutoCAD applications that utilize Object Data. It may be necessary to utilize the AutoCAD API tools of AutoLISP, Visual LISP, VBA/VB, or VB .net to output a database file according to my controlling application’s logic using a customized script. I would then re-join to the CAD features from within ArcGIS to my output table of attributes using the AutoCAD entity handle as a key field.

Please read the comments from Dale Lutz below (click the comments link).

Continue to Part 3

The Mysteries of AutoCAD Object Data: Part 1

2006-12-06T10:10:00.000-08:00

I just had a conversation with my mother in law regarding ideas for gifts for my 13 year old daughter. She called to get some suggestions from me. I asked her if she had seen the Christmas list my daughter had compiled that was posted on our refrigerator at home. Her comment was, "Yes … (then a pause)… I read it, but I didn’t know what any of the words meant. "

Sample entries: … a Bluetooth Earbud, Aurvana Headset, Zen Microphoto MP3 silicon Skin, Manheim Steamroller CD…

My daughter lives in an era once removed from her grandmother. The world has been rewired (or rather unwired) since the gift buying days for her once teenage daughter (my wife). Even though my mother-in-law could read the list it doesn’t make any sense to her without help from the "controlling application" in this case, my wife and I, her granddaughter’s parents.

Initially the mechanical drawing pencil of AutoCAD was developed without the concept of user defined attributes. With the later introduction of the AutoCAD block attribute, text tags could be added to a point symbol to hold user defined attributes. I use AutoCAD block attributes to store descriptive information about points in AutoCAD as if they were GIS point features. These block attributes have a tag name that can be utilized like a field name. Multiple block attributes can be associated with a single block/point symbol to mimic a database record. The block attributes is limited in field type to ASCII text. ArcGIS supports these block symbols and attributes as fields in the CAD virtual attribute table and attempts to apply a field type to numbers or integers if the values are consistent throughout the drawing. Block attributes although easy to create, edit and read are only valid for point symbols (block inserts). There is no way to create similar attributes for AutoCAD lines or polygons.

The modern method of attribute data storage for AutoCAD entities is to use AutoCAD Object Data or external database links. For example the AutoCAD ad-on customization code that extends AutoCAD for mapping, Autodesk Map 3D uses this technique. Standard AutoCAD entities can be tagged with x-records that are stored in a section of the AutoCAD drawing called the data dictionary. Also stored in the AutoCAD data dictionary are things like M-Line Styles, Line Types and Groups. Both the schema (the fields names and data types), as well as the attribute values themselves are stored in the AutoCAD dictionary data constructs.

Industry standard interoperability tools have the ability to access and read the AutoCAD data dictionary like all other parts of the AutoCAD DWG/DXF file. However, the x-record values for object data style attributes are stored as binary chunks of information simplified for storage according to the encodings used by the controlling application. This means that although I as an AutoCAD user could use AutoLisp to read the value of x-records from the dictionary, what I see is just a proprietary blob of binary data. The information in the binary chunk could be analyzed, but because the meaning of the binary data is held by the controlling application it is like removing all the vowels, punctuation and spaces from a paragraph and then converting all the letters to numbers. Without any context whatsoever, the data is unusable. All that to say ArcGIS 9.2 still does not support AutoCAD Object Data.

Here is one resource that discusses the creation of GIS friendly CAD data for mapping.

Continue to Part 2

Creating AutoCAD 3D Polylines from GIS Features

2006-11-08T15:05:00.000-08:00

My youngest daughter, Evie, turned 3 last week and to celebrate I can talk about 3D things.

How do you create a 3D Line in AutoCAD using the ArcInfo EXPORT TO CAD geoprocessing tool?

In Microstation the default linear element that gets created by the EXPORT TO CAD tool is a complex line string, which for 3D Microstation files is already a 3D element. In AutoCAD there are different types of complex lines; the Polyline, the Lightweight Polyline and the 3D Polyline. The EXPORT to CAD tool by default creates lightweight polylines.

Therefore if you have 3D linear features in ArcGIS and you’d like them to be 3D linear features in AutoCAD you have to override the default behavior of the EXPORT TO CAD tool by including a field in the exported feature classes’ attribute table called [CADType] and then populate that field with the string ‘3D POLYLINE’ for all the linear feature that you want to be created as 3D Polylines in AutoCAD.

For more information on creating CAD data in ArcGIS you can view several linked articles found in the ESRI Knowledge Base.

CAD Property Field Name Changes

2006-11-03T15:58:00.000-08:00

Hannah, Hannah, Hannah, Hannah, …oh my!

Oh no!... get ready for another season of GIS and CAD basketball metaphors and anecdotes. Its that time of year again when I breakout the basketball sneakers and my sweat suit and mix it up on the court with a bunch of Jr. High School girls as their assistant coach. In this school of around 50 students, the freshman girls basketball team hopefuls that assembled for the first team practice this week, 4 of the 14 girls are named Hannah. If you add to those to my daughter Holly and, Heidi we’ve got a lot of H’s.

We quickly needed to rename them all. Now Smitty, Scooby, Chip and Tweedles are getting used to their new names.

Here are a couple of ArcGIS CAD feature attribute property name changes you can look forward to in ArcGIS 9.2. These changes made in the ArcGIS CAD feature attribute table property field names were done to make them consistent with the geoprocessing tools, especially the field name driven features of the EXPORT TO CAD geoprocessing tool. Where meaningful both the old and new names can now be used with EXPORT TO CAD.

AutoCAD block names used to be stored in the field named TEXT. In ArcGIS 9.2 this field has been renamed to REFNAME, to more accurately reflect the scope of values that can be held in this field. Other entities values that might share this field share this field name are Microstation tag sets, attribute tags names, block attribute tags, and text values.

Both ROTATION and ANGLE can be used to denote the rotation angle of CAD entities and are recognized by the EXPORT TO CAD tool.

Another useful bit of renaming of fields comes by using the MAKE FEATURE LAYER field information parameter and also the MERGE tools field renaming capability. I can use existing field names and rename them as part of the operation of exporting data temporarily as in the case of the MAKE FEATURE LAYER tool, since it only make the change to the field name in memory. In the case of the MERGE tool I use the field renaming feature to make more meaning of the values in the CAD file, especilly if they correlate directly to a data field. This often occurs in a text value like REFNAME, TEXT, LAYER or even LINESTYLE.

What’s New In ArcGIS 9.2 for CAD: Part 11

2006-10-24T10:55:00.000-07:00

This Top Ten List Goes to Eleven!

In the rock-n-roll (rock-umentry) parody This is Spinal Tap there is a scene where visionary lead guitarist Nigel Tufnel is being interviewed regarding some of his creative innovations. One technical innovation was that his amplification equipment was specially made to go one higher than anyone else’s. His amp’s dials went to 11 instead of just 10. When pressed by the interviewer “Why don't you just make ten louder and make ten be the top number and make that a little louder?” ... the confused guitarist in frustration reiterated the significant difference with the refrain… “…These go to 11!”

In the spirit of Spinal Tap let it be known this list top-ten list goes to eleven! Since the publication of the official lists of improvements to CAD interoperability in ArcGIS 9.2 there have been a couple more improvements that have just made it into the software prior to its release.

11a.
AutoCAD Custom Object’s proxy geometry is now supported as ArcGIS CAD features. This means custom objects created with tools like Autodesk Civil 3D or Autodesk Map 3D will be read by ArcGIS as CAD features. The custom object data that may be associated with these CAD objects and the special geometric representations are still locked away from the standard industry interoperability tools in a proprietary Autodesk encoding format. However, for the first time you’ll now see the proxy geometry in ArcGIS.

11.b.
With the addition of the Export To CAD tool in ArcGIS 9.0 I have been able to append to CAD drawings using ArcGIS. However in ArcGIS versions prior to ArcGIS 9.2 a CAD drawing was opened once and cached in memory. Any changes to the CAD file on disk where ignored. In ArcGIS 9.2 the CAD file is refreshed automatically when the drawing is modified. This is especially important when CAD drawing data is published as part of an ArcGIS Server Map Service. These CAD files may be modified while the map is being served. Any changes to the CAD drawings are now reflected in the map service.

What’s New In ArcGIS 9.2 for CAD: Part 10

2006-10-16T09:25:00.000-07:00

Leveraging the Improvements to ArcGIS 9.2

I just returned home from Albuquerque after attending ESRI Electric Gas Users Group conference there. It was a very pleasant time to be in Albuquerque and it just happened to coincide with the international hot air balloon festival. It made me think that even a blog like this can be useful when you think that all those balloons take flight because of a lot of hot air! It was nice to meet with all of you who attended the EGUG conference. This group is heavily involved in both CAD and GIS technologies and their questions and feedback are representative of why I do what I do.

Getting back to the topic of this series... Perhaps the most powerful enhancements to CAD Interoperability are the changes made in all other parts of ArcGIS. There have been many enhancements to map navigation, the geoprocessing framework, and new geoprocessing tools. To get a good overview of all the changes in ArcGIS 9.2 you can visit the ESRI.com for what's New In ArcGIS 9.2.

Here are just a couple of my favorite ArcGIS enhancements:

I can now manipulate the wheel of my wheelie mouse to dynamically zoom in and out in ArcMap, and also re-center and pan during the use of any other tool. This allows me to navigate without specifically going back and forth to the toolbar to select different tools. These navigation tools work while other tools are active.

One of my favorite new geoprocessing tools in ArcGIS 9.2 is the ArcView SPATIAL JOIN tool. It allows you to perform a proximity based join between two feature classes, like CAD Annotation and CAD Polylines for example, all within geoprocessing. In ArcGIS 9.1 and previous versions I have to use the ArcInfo NEAR tool or perform the spatial join using the user interface options of ArcMap. The difference being, now I can include the SPATIAL JOIN as part of a geoprocessing model or script.

Geoprocessing iteration has been added in ArcGIS 9.2 for all tools in the form of a batch processing mode and using iteration properties available inside Model Builder. These iteration tools allow me to perform looping operations within models and/or execute any system or custom tool in a batch mode where the variable inputs for the tools are driven from values entered into a grid control.

Model builder now supports the use of model variables or properties used by reference. Any exposed geoprocessing property in model builder can be used as a variable by reference in any other property. Furthermore those values can be concatenate and used much like scripting variable. To use any property in the model as a variable I simply include the text name of the property’s bubble within percent symbols, like this %My Variable%. I can use that notation to concatenate the value of that bubble in other parameters in the model. Using the Model Builder variable in combination with iteration makes Model Builder an even more powerful applications development platform. More logic and workflow modeling can be done directly in model builder without having to move to a scripting environment like python

Remember all of the documentation for ArcGIS 9.2 is already availble online.

Continue to Part 11

What’s New In ArcGIS 9.2 for CAD: Part 9

2006-10-03T14:16:00.000-07:00

Georeferencing CAD Drawings

My daughter Holly was on a television game show this weekend. We enjoyed cheering-on the kids. It was fun to be part of the studio audience. The audience was a “character” in the show. We had two handlers who told us when and how to cheer to make the show more fun for the contestants, and more exciting for the TV viewers. The producer and the crew film a show for entertainment, while my daughter competed for prizes; it was interesting to see it all come together. I am happy to report that Holly’s team was victorious, and I was very proud of her regardless.

When CAD files are drawn with a scale, or within a relative coordinates system (ie: lower left corner is (0,0), etc…) their coordinates need to be shifted, re-scaled and or rotated to be usable with in a GIS and its georeferenced view of the world. For all the characters in the map to come together in a useful way they have to share the same coordinate system. In ArcGIS the way to define the parameters for how a CAD’s relative coordinates system needs to be adjusted is using a world file.

ArcGIS 9.2 the georeferencing toolbar has been enhanced to create a world file for CAD drawings. The georeferencing toolbar provides interactive tools to move, rotate, scale, fit to display and snap control points to geometry in the process of relocating a CAD drawing and aligning it with properly georeference features in the GIS. The end result of these interactive repositioning tools is the creation of the ArcGIS world file that stores the parameters for the coordinate shift for the CAD drawing. Whenever ArcGIS reads the CAD drawing it then looks for the presence of the world file and uses the information to apply a coordinate transformation so that the CAD drawing appears in the correct coordinate space.

In previous versions I was left to my own devices for how to define the two sets of coordinates in the ASCII text file that defined the coordinate transformation of a world file. In ArcGIS 9.2 the interactive tools allow meto visually and interactively reposition the CAD file and then save the resulting transformation in the world file.

This is how I use the new tools: When I first load a CAD file with a relative coordinates system, it appears in ArcGIS way out in the boonies some where. So, at first I don’t worry about it and zoom into a position in the map frame of ArcMap where the CAD file should approximately fit . I use the FIT TO DISPLAY option of the georeferencing toolbar with one of the CAD feature classes selected as the target data on the georeferencing toolbar... and presto the CAD drawing pops into the current map frame. If the drawing needs to be significantly rotated, I might use the rotate button on the toolbar to rough it into position and then use the nudge tools and scale tools to get the file close to its final position. Next I use the control points tool to snap to two points in the CAD file and two points on existing Map to get an exact transformation.

To enable interactive snapping to verticies in ArcMap I must be in an edit session. Since CAD feature classes are read/only in ArcGIS I need to temporarily edit some GIS data in the drawing. I need to use the START EDITING option on the editing toolbar, where the target feature layer is an editable GIS layer. I can then snap to any of the data in the map frame using the ArcMap snapping tools. I don’t actually need to edit anything, but rather just turn on and off the snapping. Once I am done defining my two sets of control points, I select the UPDATE GEOREFERENCING option on the toolbar and I am prompted to save the world file. I then terminate the editing session without having to actually make or save any edits.

Continue to Part 10

What’s New In ArcGIS 9.2 for CAD: Part 8

2006-09-29T16:58:00.000-07:00

Block Attributes and Tags as Annotation

With the increase in home values and housing costs these days it is becoming less likely that any of us who have bought a home in the last couple of years will ever actually pay off our mortgage. My monthly property tax bill is more than the previous owner’s mortgage payments on the same property (Granted the previous owner was the original owner of the house and he had bought it over 40 years ago.)

I’m wondering, is my goal to make sacrifices over the next 30 years and pay off the mortgage, and reduce my costs in old age? Or, do I consider my home an investment that I will cash in to pay for my retirement some time in the future? If so, who cares if I pay it off or not? If I were a financial advisor I might warn myself against putting all of my eggs in one basket, or making my nest egg in my…a… roost…or… (I think my analogy has gone wrong)… anyway diversify, yes diversify… I guess.

Well… I come back to the question again; is my house a lifestyle and quality-of-life asset or is it a financial investment? Since a Blog is a conversation you have with yourself, I will answer myself. Both… the answer is both. Homeownership is both a quality of life choice (something you would pay money to have) and an investment (something that can increase in value and provide you an income over time).

In ArcGIS Microstation tags and AutoCAD block attributes are considered tabular attributes of a CAD entity and in most cases that is how they are used in CAD maps. For that reason when ArcGIS views a CAD drawing as a set of features it has always included the block attributes and tag values in the feature attribute table of the CAD features.

It is common in ArcMap to annotate features in a map with attributes values stored in a feature’s attribute table. The same thing is true in CAD. The fact that block attribute values are visible or invisible is enough to warrant similar treatment in ArcGIS. Tags and block attributes SHOULD be included in the ANNOTATION feature class of a CAD feature data set.

In ArcGIS 9.2 Microstation tag values and AutoCAD block attributes ARE included in both the feature attribute table of the entities they are linked to as well as being included as annotation in the CAD Annotation feature class. Previously I would have to use the labeling feature of ArcMap to make the block attributes visible, by selecting the tag or block attribute as the field to label. Or, I would have to convert the values in the attribute table to a geodatabase annotation feature class as a separate step in ArcMap.

Continue to Part 9

What’s New In ArcGIS 9.2 for CAD: Part 7

2006-09-21T14:25:00.000-07:00

CAD Feature Dataset as ArcMap Group Layer

Tonight my wife’s piano students are having a recital. Most of their recitals are held in a hall in a church, but from time to time we host them in our home. Tonight the recital is going to be in our living/dining rooms. To accommodate all of our guests we bring essentially every chair we own and rearrange the living room into concert seating. Luckily the piano is on wheels and can be easily moved.

Like collecting all the chairs spread out in all the different rooms in our house, it makes good sense to organize the feature classes belonging to a CAD file into an ArcMap Group Layer. organizing drawing layers in ArcMap into group layer collections makes for more harmonious viewing. ArcMap group layers allow you to associate multiple layers as a single entry in the table of contents and then control the collection of layer’s visibility display properties as a group.

In ArcGIS 9.2 grouping the POINT, POLYLINE, POLYGON, ANNOTATION and MULTIPART default CAD features classes of a CAD drawing into an ArcMap Group Layer is the default behavior when the entire blue folder dataset is added to ArcMap.

If you select a single CAD feature class from within the dataset folder it is added individually as a single map layer.

With a CAD feature datasets improved default rendering coupled with the automatic layer grouping in ArcMap there are two less reasons to consider the CAD Drawing Layer representation (white icon) in ArcMap.

Continue to Part 8

What’s New In ArcGIS 9.2 for CAD: Part 6

2006-09-19T11:44:00.000-07:00

Improved Rendering of CAD Features Classes

Hotrods and choppers used to be salvage vehicles built by people who couldn’t afford something new. Now, more new cars and motorcycles are being designed to look more like those customized versions. Ironically, I suspect this is a move by motorcycle and automakers to capture the lower-end market that can’t afford the modern choppers and hotrods we see built on the discovery channel!

Like having the styling of the hotrod and the reliability of power steering and power breaks, people want the benefits of both methods of working with CAD data in ArcMap. They want the feature class access provided by the CAD Feature Class (blue icon) and the default CAD symbology of the CAD Drawing Layer (white icon). Most often people choose the blue icon to add CAD features to the map, and the first thing they do is change the symbology of the CAD feature class to make it look more like the CAD file was drawn in CAD.

In previous versions of ArcGIS, CAD features are treated like other GIS data sources and are assigned a single random symbol for the entire feature class. In ArcGIS 9.2 the initial symbology is based on the CAD symbology. CAD color, line style, font, line weight and other information is used to draw the CAD features like they appear inside the CAD application that created them. With the release of ArcGIS 9.2 the need for the two different methods for working with CAD data is greatly diminished. With ArcGIS 9.2, I can’t think of a good reason to use the CAD Drawing Layer (white icon) anymore.

In ArcGIS 9.2 you can still use the CAD Drawing Layer (white icon) to draw all of the CAD entities with CAD properties as a single layer; however the new default symbology for the CAD feature class is actually better. For example, the white icon doesn’t support true type fonts, standard CAD line styles or line weights. Work has been done to create a CAD symbology set for standard CAD symbology values including line style, line weight and standard CAD color values. In ArcGIS 9.2 the “more useful” CAD feature class representation (blue icons) of the CAD data, also has superior default symbology, as compared with the single CAD Drawing Layer (white icon).

Improved default symbology for CAD text associates true type fonts used in CAD to true type fonts available in ArcMap. Default values for complex CAD text justification are also improved, which means CAD text in ArcMap looks more like it did in CAD.

Continue to Part 7

What’s New In ArcGIS 9.2 for CAD: Part 5

2006-09-07T15:17:00.000-07:00

UI Standardization and Expanded CAD Data Help

I'll be heading to IHEEP 2006 in Williamsburg, VA next week and I hope to see some familiar faces working in transportaion there. I attended an EGUG conference in historic Williamsburg a couple of years ago. While there I learned more about early US history and government than I had learned up till then. I look forward to resuming my conversations with Patrick Henry and the gunsmith!

I will also be attending this year's EGUG 2006 Conference at the Hyatt Regency Tamaya Resort in Albuquerque, New Mexico where I'll be presenting a technical session on GIS and CAD Translation and Interoperability.

Today I’ll cover two new features in ArcGIS 9.2 for CAD: ArcGIS User Interface standardization and ArcGIS includes a help section dedicated to working with CAD data.

For the UI changes you can view the differences and for the help it probably best that you just read it.

The UI changes only affect GIS users expecting to see something a certain way. In the past dialog boxes that were associated with CAD data were different, for no real reason. In the cases where the dialog boxes are specific to CAD data, like the Layer Properties dialog box there are enhancents that give you more information about the layer in a more intuitive format. Here are some examples of new dialog boxes for CAD Feature Classes in ArcGIS 9.2:

One nice thing about the new help system for ArcGIS 9.2 is that it is online now for you to read in advance of the release of ArcGIS 9.2. Included in the help system are the descriptions of the new dialog boxes.

Continue to Part 6

What’s New In ArcGIS 9.2 for CAD: Part 4

2006-09-05T10:32:00.003-07:00

Improved Text/Annotation Support

I have a handy man friend of mine who has a bumper sticker on his truck that reads:

"If It Ain’t Broke, Fix It Till It Is!"

...Agreed it doesn’t inspire much confidence in his work, but for anyone who ventures into the miry world of doing-it-yourself it has a ring of truth to it.

I have a little mechanical machine that cleans the bottom of my pool. I acquired it from the previous owner of the house as part of the pool equipment. It was the only inanimate object that he had ever named (Henry) in honor of the fact that it did such a good job at what it was supposed to do. That device retails new for around $500 and this weekend it stopped working after some 20 years of daily use. On the web I was able to find an exploded diagram of all the parts of the unit, so that I could take it apart with at least some confidence that one or another part could be disassembled. I broke 4 parts while doing so; Two plastic bolts, a wheel bearing set, and a quick release fitting! The parts that originally needed replacing were the axel bearing sets. After two days and 3 trips to the pool supply store I finally got what I need and Henry never worked better!

Like Henry, Annotation/Text support has been improved to function more like you would expect it to. Specifically the enhancement to CAD text rendering is that the CAD properties are used to render the file based annotation symbology in ArcGIS 9.2 rather than defaulting to black ARIAL font. When a CAD file uses a true-type font in the CAD text style definition ArcGIS will also use that same true-type font to render the characters. ArcGIS 9.2 still does not support CAD vector defined fonts. However, positioning and the general symbology for viewing in ArcGIS and generating CAD text using the Export to CAD tool are significantly improved.

Continue to Part 5

What's New In ArcGIS 9.2 for CAD: Part 3

2006-08-30T10:23:00.000-07:00

More Properties

When dealing with CAD data in ArcGIS you never know how a subtle varience in the CAD properties might be useful in distinguishing one potential GIS feature from another. Although there are currently more CAD properties supported in ArcGIS 9.1 than most people need the addition of several new CAD properties target some useful omitions.

Worthy of note are the CAD properties Elevation, DocPath, Angle and the collection of CAD Layer properties.

Although there is a specific definition of the Elevation property in AutoCAD, in ArcGIS 9.2 that definition has been loosened so that points, even 3D points that have a Z’ Coordinate will have the elevation value included in the table in addition to Z’ coordinate being a part of the 3D geometry. A related improvement is that the ArcInfo Export to CAD geoprocessing tool now supports more fully the Elevation field to control the elevation of CAD entities that are exported.

The new field DocPath is included in ArcGIS 9.2 for all CAD feature classes. In this way I can keep a record easily of which drawing file I am working with. I can retain this value during conversion to keep a record of where the information originated. A related benefit is the automatic hotlink feature of ArcGIS that recognizes path names in ArcGIS tables. If you use the identify tool in ArcMap for example on a complicated map that may contain several complicated and vertically tiled CAD drawings, you can identify a single feature and then in the grid control of the Identify command you can click the hotlink icon to Launch the CAD application on you desktop that is linked to that drawing file extension. So if you have AutoCAD on your desktop you can use ArcMap to launch the appropriate CAD file by simply browsing a key map of CAD files in ArcGIS.

The rotation value of Cells and Blocks and other point feature is now included in ArcGIS CAD Point feature classes. This was added so that I can now rotate symbols in ArcGIS based on the same rotation values used in the CAD file. The new rotation values are in decimal degrees rather than radians (so you don’t have to do the math).

Another addition are the Enity/Layer symbology properties for CAD entities. In ArcGIS 9.1 and previous versions there was a single value for CAD properties such as Color. I did not know if that value was the entity color or if the entity was BYLAYER or BYBLOCK, all I could discern was that that was its display color. In ArcGIS 9.2 you get the display properties, entity properties and layer properties to distinguish between; for example, a red entity and an entity on a layer colored red, with an entity color of BYLAYER.

There are several other CAD properties that have been added that are maybe a little more esoteric, but potentially useful.

Continue to Part 4

What's New in ArcGIS 9.2 for CAD: Part 2

2006-08-24T13:15:00.000-07:00

I could make a case for the fact that the pay at the pump credit card transaction technology is one of the most useful innovations of all times, ranking up there ketchup in a squeeze bottle and the internet. That is if it weren’t for the fact that there are so many different interfaces that have arisen for the different pumps. In the glory days of pay-at-the-pump you would swipe your credit card and select the gas you wanted to use and pump away.

Then the internet birthed the profitability of identity theft and the interface became more complex, often you must enter a zip code now… another disturbing variation was in invent of the option to not receive a receipt, car wash… etc. Other times the interface needs you to tell it if you’re going to pay cash or debit or credit (like it can’t tell when you swipe the card!) some want you to confirm with a [Yes] others with the [Enter] key. And, of course there are several variants as to where the [Yes] and or [Enter] keys are located. You can see for yourself that this is the essence of poor design. Think of all the gas stations you’ve been to where the gas station owner, tiered of answering everyone’s questions about the broken pump, has taped a big arrow or circled the magic key with a permanent marker!

A standardized interface would help me not have to be apologetic about my vote for pay-at-the-pump’s nomination to the technology hall of fame.

Change for the sake of change is just confusion unless the change was designed to eliminate an existing confusion. The original consensus that spawned the decision to create one file icon for the Feature Dataset of a CAD file (blue folder) and another file icon (white) to represent the Drawing Layer view of a CAD file has been lost. Scanning the user forums and viewing statistics from logged technical support calls regarding the subject, provided a compelling argument that something was wrong with the current arraignment. People didn’t know which representation of the data to access. However when the data is organized together in one folder there is a much clearer picture of how ArcGIS sees a CAD file.

Instead of seeing two files in the file system browse tree for every CAD file you will now see just the single CAD feature data set (blue icon). Inside the CAD Feature Dataset you will still see the standard CAD feature classes (POINT, POLYLINE, POLYGON, ANNOTATION and MULTIPATCH); these are the original GIS feature sources available from the CAD file. In ArcGIS 9.2 the CAD Drawing Layer (the white file icon) is included inside the CAD File Feature Dataset. As described in previous posts this icon represents the entire CAD file as a single source of geometry that can be used inside ArcMap as a single layer.

Additional improvements to ArcGIS that I will discuss in this series will help make the case that this CAD Drawing Layer may fade in importance and may in the future disappear all together…

Continue to Part 3

What's New in ArcGIS 9.2 for CAD: Part 1

2006-08-22T11:16:00.000-07:00

My daughter Evie has made tremendous strides in her swimming this year. She is only two and a half but can already swim the length of the pool, albeit closely monitored. Entirely self-taught (sister encouraged) she can float on her back, float face down, move backwards while kicking, climb out of the pool from any edge, grab the pool edge from anywhere inside the pool, can pull herself hand-over-hand round the entire edge of the pool, she can tread water for minutes at a time, and performs a modified crawl stroke with her face under the water, stopping to take a breaths while treading water. The secret of her success is immersion. She has been swimming every single day since the summer started.

Much to Grandma’s displeasure, she often ventures into the “deep-end” without hesitation. My 13yr old is quick to point out that for Evie (who cannot touch the bottom of the pool at any point accept the first and second step), the entire pool is the “deep-end”. In that way she has an advantage; she has no prejudice for one level or the other, everything is over her head!

In the spirit of something new, lets talk about the things I like most about what is coming in ArcGIS 9.2 as they relate to GIS and CAD Interoperability.

Top Ten New For CAD in ArcGIS 9.2 :

The ArcGIS CAD Drawing Layer has been moved into the CAD Feature Dataset. (The white icon is now found inside the blue folder).
The CAD Attribute table of a CAD Feature Class includes More CAD Properties. (Notable additions are an angle value, the CAD file name and an elevation value.)
Annotation/Text Support has been Improved. (Better CAD TEXT Rendering and Better TEXT creation.)
The CAD Property Sheets have been standardized to work the same as other ArcGIS feature classes.
ArcGIS includes a help section dedicated to working with CAD data.
CAD Feature Classes are rendered in ArcMap using information from the CAD drawing. (Where possible the CAD colors, line styles and fonts are used by default to drawn features in ArcMap.)
When an entire CAD file is added to ArcMap the five standard CAD feature classes are organized in the Table of Contents as a Group Layer.
AutoCAD Block Attributes and Microstation Tag elements are included in the CAD Annotation feature class. (Now tags and block attributes can be used as annotation without having to use the Label tool to see the information on the map.)
The ArcMap Georeferencing toolbar has been modified to support the interactive georeferencing of CAD files. (You can use the tools to fit, rotate, nudge and snap a CAD file into its proper coordinate space. And, then have it automatically generate a world file (.WLD) for you.)
The biggest improvement in my mind for CAD interoperability in ArcGIS 9.2 are the other non-CAD-Specific improvements to ArcGIS 9.2, which Include: Batch processing of any geoprocessing tool, Iteration capabilities in Model Builder, Model Builder Variables, Roller Mouse Pan/Zoom navigation in ArcMap, The AutoCAD and Microstation Image Server Clients, ArcGIS Server Map Services with embedded CAD data, … and more.

Continue to Part 2

Exporting Attributed Data to CAD: Part 5

2006-08-18T13:48:00.000-07:00

Microstation MSLinks

Like the North Pole in December, the weeks leading up the ESRI International Users Conference are filled with many GIS elves busily putting together presentations, writing sample code and making big pushes to finish software. This year was no exception. Now that the successful event has passed, I’d like to say hello to those I met in person in San Diego and thank you for your kind words regarding my presentations there, and your positive comments about this BLOG.

In my last post I talked about AutoCAD extended entity data (EED/XData). Microstation design files have a similar albeit more useable form of “xdata” that has been used to store extra information on entities that can be used to indicate a database record in a table to which a Microstation drawing element can be linked. Better yet Microstation has standard user interface tools to manage these links. This make the creation of MSLinks and a companion database table a valid and useful way to store GIS attribute data on Microstation drawings that are generated from ArcGIS feature classes.

Using MSLinks is a traditional means to link design file data with data stored in an external table. The ArcGIS Data Interoperability Extension can make use of this data structure when Creating CAD data from GIS data. Use the MGE/Geographics format as the output format when you export Microstation drawings from ArcGIS's Data Interoperability Extension. The MSLink will be populated with a value that corresponds to a record in a table that gets generate as part of the creation of the Microstation drawing.

The Microstation MSLink technology is pretty straight forward. An MSLink is an integer that coorespondes to the record number of a table. A companion value called and MSCatalog value can also be stored on the element, which is another integer that coorespondes to numbered list of tables (Catalog). In certain applications the two values together can point to a specific record in a specific set of numbered tables.

Note: Exporting Microstation files with MSLinks is not available in the ArcInfo EXPORT TO CAD tool.