How can I programmatically access the ArcGIS 3D Analyst Toolbar's "Features to 3D" command?

Question

I need to take a 2D shape file in the ".shp" format that ArcGIS accepts, and add 3D information supplied by a raster DEM. I'm looking for how to do this with the ArcObjects API. I'd like to do it in C#, but examples in any .NET language would be welcome. The only thing I've been able to find are descriptions of how to do this manually in one of the ArcGIS desktop apps. Like this helpful HowTo article, or the wonderful full color illustrations on page 22 of this tutorial. That's great and all, but I need to use this feature in the middle of an automated chain of operations. I don't want to have a manual step in the middle.

Answer 1

OK. I figured it out. I'm jotting down an outline of what I did here in case anyone else runs into the same problem.

The key method is ISurface.InterpolateShape. It will copy an existing 2D IGeometry and add 3D information to it from a surface (raster or TIN). I translated this example VB6 code from VB6 to C#, and modified it to call InterpolateShape for each copied IGeometry in the input shape FeatureClass before inserting it into the output FeatureClass.

I won't post any of the code here because I developed it on my company's dime, but this should be enough to figure it out reasonably quickly. Hopefully this will help some other struggling developer get through the problem more quickly.