Hi,
I've taken an interest in shader programming to make effects to use in XNA. Shader programming, or more specifically, HLSL is not something with which I'm familiar. I'm an experienced coder and I'm familiar with the maths of 3D lighting/shading etc. so I don't need help in that area.
I've looked at a few .fx files and tutorials in an attempt to figure out how to create my own. However, I'm finding the tutorials a little vague and they generally seem to give how to's in specific shaders. They don't tell me how the return values of pixel shaders are used in the final rendering.
For example, I'd like to create a shader that could do some glow effects. I'd like to write one of my own instead of downloading it, if only as an educational exercise. Taking this example, what should the output of a pixel shader return? Since I don't know how the return value of a pixel shader i used, it's tricky to figure out exactly what should return.
I'd be grateful if somebody could point me in the direction of some docs that would help me with what i've discussed. I'm planning to use something like NVidias FX Composer to produce shaders, but I would still like to understand what I'm doing.
Thank you for your time.
Majikat.