Hey, thanks! I'll do that. Hmmm. Ya know, I get this - likely rotation matrix singularity, tan2(), etc. Good call. Sitting Blue; aren't you the one who made that very nice terrain mapping tutorial, the one that I have studied in detail? (Thanks AGAIN!) You might want to check out my last two posts which are somewhat successful attempts finally at getting terrain mapping working. In the first (W'fall VUE) I describe my scaling attempts a bit. The second, "Urban Aorta" has all scaling set at one and accomplishes the same thing via a different route: 1: Create terrain, set resolution, flatten (z height = 0) and fit aspect ratio. 2: Create texture for the terrain, Object-Standard, flat. Make sure texture is positioned exactly on terrain as you want it. Bump Gain = 0; optional. 3: Position camera directly overhead and adjust until terrain/texture fits camera precisely. (Should like a photograph) 3: Render, and save image. 4: Open saved image in terrain. Now as you change the terrain height to non-zero, the texture sits exactly registered on the terrain (subject of course to how well you did #2 above (use a pocket calculator to do the trig.) - Clark