Cheers, that was just what I was afraid of might happen. Guess I’ll add the extra polygons, and just make sure it doesn’t take too much of the UV. So what about the two sides things, the outdoor and indoor side of the wall, should I keep them the same or set each side to have different material IDs, so they can be different? because in my example up there, I would end up with 5 material IDs then, and I’m afraid of the performance hit I might get.