Michael, I was using the .obj but with the n-gons rather than the quads and triangles. Shall try that.

Tim

I, too, use SimLab very much as a novice, and mostly for Simulation.
I posted a question on the forum asking the best file type to use.
Here's a link: http://www.simlabforum.com/viewtopic.php?f=12&t=9872&sid=a1512b857f5cefd6a60d7814e9202650

Mike.