I'm working on my first attempt of PTI editing into hammer (I know, shame on me !). It's early (early) wip and you can find some shots here : http://imgur.com/a/1HLII/
As you can see I got this lightining problem on some brushes textured with plastic walls. They just appeared to be black, not rendering the lightining of the room. I've been looking for some topics here and on the wiki but anything i've found was able to solve it. It's not vertex textures and there is just a framework prop_static on it (could it come from here ?). I also thought it could come from the overlay that i put on it, but when removing it's still black. Thanks in advance for helping.

