specular + diffuse lightmapping in a single operation
Ok, simple question really: I'm doing global illumination using light maps... I'm doing three passes: first base material, then multiply by a diffuse light map, and a final add with a specular light map. Results are very good, but my question is: can this be achieved in just two passes? I mean, forget about multitexture for a second: is there any way to encode a diffuse lightmap so it can be in the range from 0 to say 4, so for values between 0 to 1 it acts like a diffuse map, and above that it produces specular highlights? As you might guess, i'm talking about static lightmaps... not dynamic.