My question has to do with what Stella is looking for when you import a 4D off file. In your standard polychoron only two cells meet at each face. Is it possible to have more than two cells meet at a face interpreted correctly by Stella?

I am specifically thinking of projecting 5D polytopes into 4 ...

I would like to request an augment function for 4D polytopes.

Thanks.

If the OP wanted to know how to remove a vertex from a polyhedron, then the ideas presented are good. However, if he just wanted a truncated icosahedron, then it already exists in Stella as the gyroelongated pentagonal pyramid, J11, a Johnson solid.