multi_compile a shader with and without GrabPass

Hi!

I am writing a custom shader for our water surfaces, which uses a texture from a GrabPass call to create distorted refractions. Right now I'm trying to implement differend detail levels for the shader. In one of the low detail versions I intend to disable the distorted refractions using simple alpha blending instead of sampling the grab texture. When disabling other expensive features, using multi_compile and #if directives did just fine, but it cannot be used to exclude pragmas, or anything outside the cgprogram.

Is there a way to disable the GrabPass call in certain versions of the shader without writing a different shader or subshader?

Thanks in advance!

Szali

 

Not that I know of. I believe the common technique is, which you don't seem to like, to provide different shaders and use the LOD tag and Fallback system instead.