Smallworld, What version of Rhino do you use? Have you done any searches on using the detailed export options out of Rhino? I use Rhino 2 and there is some good info out there on export. Using the simple slider controls is not a good idea with a Rhino file that is complex. Everything gets meshed to the same level. There is also an option to force Rhino to export mostly quads so de-trangulating might not be needed as much. If you can't find what you need, let me know I have it archived someplace on my hard drive. I've kind of moved from nurbs to poly modeling with Hexagon. wayne k guam usa