Hi all,

I am having urgent trouble with a project involving 3d modeling of terrain. This is a graduate-level project requiring ArcMap and Star-CCM+ software as well, which I am capable in, so I overlooked taking on the responsibility of modeling in Civil 3D (which I am a beginner at) and converting file formats. I was hoping one of you had some suggestions (and if this is in the wrong place, I apologize / please let me know)

I am attempting to turn an elevation model of the island of Jerba into a 3D CAD model for use in computational aeroacoustic modeling (any of the typical file formats - .igs, .stl, etc. work for importing the model). I brought the data into Civil 3D 2014 as TIN Triangles, used convtosurface, and attempted to export as an igs. The export functioned but the file won't import into the other program because it requires a watertight solid geometry. I have tried surfsculpt and convtosolid as well as to create a mesh but I am sure I am giving it invalid commands because it keeps crashing the system.

Please help! This project needs to be done asap and I am utterly lost. I have uploaded the files to an open google drive folder if anybody would like to take a look (too large to attach):

I have attached the .dwg file I have been working in (FromIGS_WithSource.dwg) as well as the original exported TIN triangle file (ZJKCAD4_4_2.dwg), the non-functioning igs model (ZJKCAD4_4_2.igs) and the raster grid file of elevation (whole elevgrid folder) in case any file is more helpful. I have access to Civil 3D 2014 and AutoCAD 2014. Please don't hesitate to let me know if there's any additional information I can give you.

Thanks in advance!

Zach