Quote - I couldn't agree more. And if you look around you here at Renderosity, after who can do that, you will find that they who succeed best are the ones who knows how to paint. No amount of mathematics is going to help you.

painters need to always start from beginning in poser to achive photorealism.  

BB's mathematics allows us to use shaders  with all lights . and this is hes point. to make something that can be used in all situations.