I'm researching the idea of trying to use a bump/normal map. I didn't believe it was possible originally, but it appears that it could work.
What I understand so far, is that a normal array is no longer needed, but that a light direction vector is used to help determine at a vertex point how much illumination is there. With that computed, the glColor (I'll have to add a glColorArray where I wasn't using one before) use updated to fake the light effect.
What I'm not quite clear on is if this is really per-pixel lighting or not. If it's only figured at each vertex, how is the rest of the bump map used? Each pixel is blended due to the multi-texture settings in glTexEnv() but there's something I'm just not putting together.
Is there anyplace that has a more complete example for how this is put together in OpenGL ES?