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.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: https://drive.google.com/folderview?...UE&usp=sharing

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