It's not clear to me from the docs that POV-Ray cannot handle multiple texture blocks for a givin solid. Empirically, it doesn't have the desired result. I think it's using the last-appearing block; but I didn't try hard to verify that. With this commit, the output should be similar to what I'd write by hand - only one block of a given type per enclosing block, with no duplicate attributes. add Show instances to aid debugging Do not output empty finish or texture blocks This is just a cosmetic preference.