Converting FDO Geometry to Drawings Coordinate System

[Anonymous]

I have written a plugin that displays shapes from an ArcSDE Geodatabase on top of an AutoCAD drawing.  The Geodatabase is in Web Mercator projection. This works fine with blank drawings, but if a user opens a drawing that has been assigned a different coordinate system (say, UTM27), AutoCAD is not projecting the geodatabase shapes to the drawings native coordinate system.

Does anyone know if or how I can make it do this transformation?

Thanks,

-andy h.

[Anonymous]

Andy,

Would you elaborate on the plugin you speak of?

It will be difficult to help without some insight into its architecture.

r,

dennis

[Anonymous]

Hi Dennis,

My plugin is basically a more user friendly wrapper for the Map 3D task pane... we have pre-defined .layer files, and I've added a Palette so users just push a button and the .layer files will be loaded, using the OSGeo API.  Then, when editing is happening, I listen for the Check In command to start and set a few properties before (LastModifiedBy, DateLastModified) on their way out.  I also have buttons that call the command for 'New Feature', and other buttons that just fire commands to the command line.

Thanks,

-andy

[Anonymous]

andy,

Your version of Map3d?

Certainly V2012 of Map3d/FDO _automagically_ does the projection to the coordinate system that was assigned to the dwg (if need be).

r,

dennis

[Anonymous]

OK, that makes sense. I think the problem now is that AutoCAD doesn't recognize the coordinate system of my Geodatabase (Web Mercator (EPSG: 3785)), sense in the Connection Window it says <unknown> under Coordinate system for the layer. Do you know how I might add it?

[Anonymous · Accepted solution]

I was able to fix the problem.  The problem was, in the Override Coordinate Systems window, there were three rows listed, one said LL84, the other two were <unknown>. I had set to override the first row with Pseudo Mercator, but just left the other two alone.  Once I added overrides for each of the three rows in that table, everything re-projected to my drawings coordinate system.  I didn't even need to add a new coordinate system, the Pseudo Mercator worked fine.

Thanks for your help!