I've written a function that randomly generates a terrain map and calculates all the vertex normals so it can be rendered wiht Gouraud shading. However, when I pass the vertices to DirectX it doesn't seem to be able to calculate the lighting in any sensible way. All normals are in three-space and normalized to (0,1), relative to thier vertices. I suspect my problem comes from the fact that this is not the way DirectX wants its normals. I have also attempted setting the normals relative to world space, but that didn't help either (although it gave me some seriously interesting lighting ~_^). How exactly is a normal defined in DirectX? Coordinates? Angles? A quick explanation of what it's looking for would be great! Also, do I have to have a material to use the D3D lighting routines? I set the color of each of my vertices manually, so I'm not sure if I need to set a material as well. *edit* I'm building against DX8.1, btw */edit*

Hmmm, that's exactly what I'm doing. I'll keep hashing away at it and hopefully figure it out.

Heh, sorry about that SimmerD ^_^. By "normalized to (0,1)", I meant that the lenght of the vertices was normalized to (0,1). Actualy values did go from (-1,1).

Anyway, I discovered the problem last night. I had made a typo when I wrote the code to calulate the cross-product for the facet normals, and so all of the z components were just plain wrong. I works great now, I had a cute little demo of it running where you could watch the sun rise and set over the terrain. Thanks guys.