April 22, 2009

Editing GIS Data in CAD: Attributes

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.


Blogger Dale said...

Don -- thought I'd mention here that the latest FME betas (www.safe.com/beta) now support reading and writing MSD-attributed AutoCAD files as well, so folks can create these from just about any format to end up using in both ArcGIS and AutoCAD. This functionality will get into the Data Interop in a future service pack or point release which will give even more flexibility in creating these MSD CAD files within the ArcGIS environment. It'll be just like cookin' with gas!!!


6:26 PM  

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