Ya'll: I've been experimenting with Bas Relief by making images of terrains from directly overhead, looking straight down. The terrain and the sides of the viewing frustum are parallel. What happens is I get a white cross in the rendering. The height of the terrain doesn't matter, with a procedural texture, I still get a white cross in the image. Interestingly, the ray tracer refines the white striping as it progressively moves to finer and finer resolution. Any one know anything about this? Thanks