After successfully instructing Global Mapper to download the high-res color aerial photo I had struggled with downloading and importing via USAPhotoMaps and the USGS site, I’ve now been able to match it up with the DXF contours I exported from AutoCAD, and get an initial 3D rendering of the terrain.

I’m not real happy with the results, however. The image and contours don’t align exactly, and moving things in GM is more difficult than it would be in AutoCAD. I think Global Mapper may turn out to be invaluable for data conversion and some visualization, but for now, it’s time to begin looking at more sophisticated tools. This is a case where having a command line would really make things a lot easier.

And while I can view the terrain in 3D, the user interface and export options are cumbersome. There is no support for the SpaceBall, the zoom/orbit controls are a bit awkward, and the 3D view defaults to a high vertical exaggeration factor, with no indication of what the factor is. I also can’t export to a movie or VRML file, and both the resolution of the texture map applied to the terrain and the extents rendered in 3D vary according to your zoom level, making it difficult to get high-quality images in the separate 3D window.