I'm trying to bring in a .dwg topo map into SW.  It's successful to bring it in as contour lines ("imported curves" in the SW tree).  During import, there is an option (screenshot below) to import 3d face entities or skip them, so it appears there are surfaces in the native file.  The attached SW file is the result of skipping the 3d faces.  When it was imported without skipping the 3d faces, it crunched for 16 hours at which point I figured it was not going to get there, and if it did the result would probably not be usable.

The goal is to ultimately build a solid model and then build some structures to see where/how they fit into the terrain, and evaluate elevations of structures and how much earth movement would be needed for various options.

I've searched the forum and found that others have worked at this also, it appears there *may* be methods to make a surface out of the contour lines, but it appears pretty dicey given the quantity of lines and points in this file.  After a basic search for Autocad output options, it appears that Autocad (but not Autocad LT) will output to .igs and .sat.  The source of the Acad file has only Acad LT.

Does anyone have access to full Autocad to try to bring this file in and then output as .igs and .sat?  Or does anyone know of any technique to import the .dwg into SW with the surfaces somehow?

Thanks in advance!

Scott