Yes, shaders are the best thing since sliced bread.
Yes, they are still quite limited.
Here is my problem:
I want to do Oran-Nayer diffuse shading with pure phong specular as well as per-pixel bump mapping. No problem.
I also want to do a sky-scattering shader. No problem.
Doing both = big problem.
I'm out of pixel shader inputs. The sky scatter shader plus the other shader require far too many inputs.
So my question is:
How do you chain shaders w/o performing multiple passes? Multiple passes on terrain that stretches to the far clip plane is totally 100% out of the question.