The Universal CAD Projection File

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?

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

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.