Thanks Peter, that does help quite a lot, I'll try some files in OFF format and let you know how I get on.

Hi everyone, I'm really enjoying using great stella and have made many interesting models, however I've come up against a problem, I'm making and importing new models into great stella and I get lots of errors, the main one is a 'model has no faces create convex core instead' type error but then ...

Thanks for the reply, I think I found out where I was going wrong. I do use the 50% truncation method but was struggling with some models. By mid-sphere do you mean mid points of faces are the same distance from the centre.

I have great stella and would like to make rectified polyhedra from a parent polyhedron, twisting the pentagon faces of a dodecahedron for example, so that they are point to point instead of back to back and adding an additional triangle face to make an icosidodecahedron. Do I have to do this with ...