ArcSDE CAD Client #6
The family is planning a camping trip in mid July with some friends. We have an active toddler and the wife isn’t too keen on the idea of tenting so much… I am not keen on the cost of renting an RV so we are sort of at an impasse. My calculations put RV rental at around $250 per night and that doesn’t count fuel costs which are rising! I figure I can build a small house for that much on the campsite and burn it before I leave! Perhaps this is yet another character flaw, but… secretly, or not so secretly now… I am really considering it! Another plan would be to drive to the destination, find the nearest U-Haul and a thrift store to buy beat up furniture, and use that for an RV. Somebody please stop me… (I’ll buy the furniture and then give it back, and get a tax write off…) It’s a client-server vacation I just access the stuff when and where I need it.
ArcSDE CAD Client is a client software application that links CAD to ArcSDE data. It has the ability to generate CAD representations from GIS features that are stored in ArcSDE layers. The process of reading the GIS feature and creating these CAD entities from data stored in ArcSDE is called “retrieving” in CAD Client. As mentioned in the previous post you can use existing CAD data to build ArcSDE databases. You can even stored binary copies (BLOBs) of entities as optional data in ArcSDE. However, you don’t need to store data using CAD client to retrieved data from ArcSDE using CAD Client. You can retrieve the simple features of any data stored in ArcSDE regardless of how it was stored originally. Only ArcSDE data stored using CAD Client will have CAD binary data associated with ArcSDE features so the only way to use this data is to RETRIEVE it back into the same version of CAD Client that stored the data originally.
There are two different options I can choose when adding ArcSDE data to my CAD session using ArcSDE CAD Client. The first choice is whether the data will be retrieved with links to the ArcSDE feature attribute tables. I'll talk about this more when I discuss the CAD Client Settings tool. The only reason you might want to disable this setting is if you are concerned about file size and you do not need to edit the features or view the attributes. Choosing not to RETRIEVE data with the ArcSDE database links will preclude that data from being edited, or the feature attributes viewed. The second option is… if and only if data was stored with the CAD Blobs retained; you can choose to RETRIEVE the CAD Blob version of the data instead of the default ArcSDE simple feature data. The other option involves adding ArcSDE simple feature data to the CAD session for the purpose of editing the geometry.
I select which features in the ArcSDE database I want to retrieve and how you will retrieve them by using a RETRIEVE template. The RETRIEVE template is created using a wizard that creates a simple file that is essentially a stored query. You can use a combination of SPATIAL and ATTRIBUTE parameters to define this “query”. For example you can query the basemap for all of the features of an ArcSDE layer that are within or crossing a given polygon, or just the parcels owned by the City. There are several different spatial operators and you have the ability to use any valid SQL WHERE clause to filter the features by tabular attributes.
I can store and reuse these templates to perform repeated or common extractions (“retrieves”) from the ArcSDE database. Unless I am retrieving the CAD binary copies of previously stored CAD data, the CAD entities that are generated will appear using the current default entity properties. If I want different queries to be symbolized differently in CAD, I change the default symbology between retrieves. If I want to use the ArcSDE attributes to drive symbology I create a custom application using the ArcSDE CAD Client API and host CAD API to read the ArcSDE attributes and re-symbolize the CAD drawing using CAD tools accordingly.
...Or, because I have ArcGIS on my machine I just use the Export To CAD tool instead, and append to a CAD drawing with data that comes from any ArcGIS data source including ArcSDE. I would run the Export to CAD tool in ArcCatalog and not from within CAD, but I could. (think ArcEngine CAD/ArcGIS VB-Automation, but thats another topic for another day, and it uses an ArcInfo license.)