Damn, Mark, like I said earlier... you rule! Yeah, I was working on the shader for a while an just can't get it to look right.... Problem is, I have a good brain model, so using the terrain would not work. However, maybe if I create a grayscale t-map like the terrain you have designed above, that may work better. Up until now I have been using wood, noise, waves, and the like to try to simulate the sulci and gyri, and it just doesn't look right... hmm....something to think about... Thanks, HG...