Cg has these ‘Texcoords’ they are float4 (4 element vectors) passed from the vertex shader to the fragment shader, and you only get 8 of them. You may use up texcoords for:/
-normal vector
-tangent vector
-binormal vector
-texture uvs
-shadow uvs
-world position
-other stuff I don’t remember
You always need a normal, you need uvs for a texture, don’t know what the third thing is, but you’re left with 5 texcoords for shadow uvs.
I don’t think that anything will be a part of p3d, when I was making my solution the goal was to have a drop in replacement for the auto shader, but in the end I made the light API different. I still think it’s easy to use, take a look, say what you don’t like and I may improve it