Our latest OpendTect v6.6.8 supports STL format. This is a format used in the Computer Aided Design industry to design 3D objects. It is used in the Mining industry to show subsurface constructions such as mines. A nice feature (not shown) in OpendTect is that you can display attributes on the surface of the 3D body. For example displaying fault attributes would show where faults are intersecting the structure

The image shows a 3D model (STL) of a part of a mine together with several GPR profiles.

The image is courtesy of BGE Federal Company for Radioactive Waste Disposal