In a normal custom glass I would use: Reflection Bias [0, 1] + 0.5 to power a regular fresnel output [math power(fresnel, result)], and let that drive mix shader of refraction and glossy. So basically I’m reshaping the normal fresnel output with a power function. Basic stuff, and doesn’t touch the extremes. And would probably work for a custom fresnel which accounts for a single roughness.
What would be the proper way to setup a custom glass where two different roughnesses are used (i.e. smooth reflections and rougher frosted looking refractions)? Should I use the custom fresnel governing refraction or the one governing reflections, or something completely different? Am I even attacking this correctly?
I need bias control and separate colors, which is kind of the point Like, 0 = More transparent, 0.5 = Regular behavior, 1 = More reflective. And I don’t want more than two shader calls (1 refraction and 1 glossy) for efficiency reasons.
Basically something like this, but using roughness based fresnel instead for each roughness and blend, instead of the single default one I’m using here, but how to set it up? The image shows glass with anti reflective coating (green tint) on some pink’ish slightly frosted glass: