For the rocks? I think it's one of the standard Bryce textures. I'm not sure which one, but it's nothing special. The building textures are the defaults that came with one of the Dystopia free sets. The only thing I made were the billboards and the signs in them. They're left over from an old project. The only thing I wish I did differently is added lights to the bottom of the billboards and maybe have done the whole shot at night. But, it would have been a nightmare to light and I couldn't bring myself to do it.