Physically-Based Rendering / Physically-Based Shaders
My very basic understanding of physically-based shaders is that they have an accurate Fresnel curve (becoming more reflective at grazing angles), and they obey energy conservation (light will not get brighter or dimmer upon hitting the material - it either passes through the surface or reflects off, but is always accounted for).
What I would like to know is: To what degree can these concepts be applied in Blender Internal in order to create more convincing (but still quick to render) materials? This would be useful for the BGE and Blend4Web as well, but the first step is to figure it out for Blender Internal.
It is my understanding that creating the physically accurate Fresnel curve in BI is easy, but that the energy conservation and accounting for "roughness" is not something BI can do because light is not handled in a physically correct way (although maybe baking from Cycles could be a workaround?).
Please correct me wherever I may have misunderstood. And thanks in advance.