SH light information in the ForwardAdd pass?

[edit]

need to clarify this a bit... "with" lights disabled.

I can access SH in ForwardBase, but not in ForwardAdd it seems unless I turn on a light, then all hell breaks loose.

I'm thinking not after trying, looking at my compiled shaders and reading what I could find, but I just am going to ask this anyway.

Is it possible to setup access to SH lighting information in the Forward Add pass? I have a clip operation (or discard) on a pixel in that pass that I do not want calculated while being able to retain the pixel information calculated in the Forward Base pass.

This small discard could save me a lot of unnecessary processing that otherwise has to be done in the Forward Base pass and just leads to crappy frame rates (50% drop from one extra statement that looks like diffuse += specular; )

 

I seem to do this a lot... comment to myself lol.

I've scrapped this whole idea (especially the idea of using clips and/or discard)in a forwardadd pass, as from what I've read it is just bad mojo and doesn't help performance (?).

I'm going back to incorporating the techniques presented by madfingers a while ago along with a pseudo RNM but instead of using texture LUTs, i'm using lightprobe data as a LUT... same kind of concept, but might be able to make some interesting LUTs that can be swapped on the fly (pre-built 3D probe cloud), changed programmatically, and controlled by an anchor override.

I've learned a lot in the course of the past two weeks... before that I couldn't even tell you the difference between the vertex and fragment parts of a shader. The quirky optimizations though... wow what a f'd up mess that is to figure out. I really wish I had a single document with those, but instead I find tid-bits here and there...