when i render out a frame, there's some kind of interference in certain parts of the frame, where light hits it. it looks kind of like zebra lines in video - multiple paralell lines that appear on my polys at a certain angle. i've gone through my settings, but i don't know how to fix it. i'm assuming it's light related, possibly a depth map/raytracing problem.

anyone see this problem before?

thanks for any help.