Ya i am confused about this whole thing. What exactly is meant by per pixel shading like used in doom 3 as well as other games. Also who originally developed this technique? Does this mean that the actual pixel can be two different colors? Also, how does per pixel shading differ from other ways of shading textures? Thanks.

Most shading is done based on the vertices and the normal of the poly in relation to the light source. This means that a light towards the vertex of a very big poly will seem to diffuse out, as it effects the other vertices less. That is vertex sahding. The problem with this, is that if you have a light in the middle of a poly the entire poly looks evenly affected by the poly, even if it isn''t; per pixel shading calculates each pixel''s shading based on light individually.

OOoohhh, stupid me!

I was thinking that each pixel could have more than one shade of a color. DOH!

Thanks for clearing that up.