SairesArt Yes I read that. That's why I'm asking this.
Basically, nearly everyone is using GGX BRDF nowadays for roughness. Corona uses it too but they put a curve on the roughness remapping the values to look more like the previous BRDF model (which i think goes against the whole point of switching to a new BRDF model).
So at the moment, you can't get 100% rough materials in Corona 3dsmax. Ondra said this will be rectified soon but I was wondering what you had done with the Corona surface implementation and how it worked.
Also, I've got a question about the Fresnel and the Fresnel map input. What is the use for the Fresnel map? I can't seem to understand how it works. I'd expect it to be a F0 input but it doesn't seem to be. And does the Fresnel input understand 1/IOR when values are under 1, like vray does?