I don't know man, i think people overcomplicate PBR for no reason. in the simplest possible terms, making something "physically accurate" just means making the shader energy conserving, right? So really, you could do that by just doing "diffuse * (1 - specular) = finaldiffuse". the bdrf just defines the shape of the…
just be aware with UDK, that anything you plug into their specular, defaults back to blinn-phong, and diffuse defaults to lambert. if you use custom lighting, you can't use their lightmapping tools or anything.
As an environment artist I think it would be more important to know how materials work. How the diffuse/specular/gloss textures interact to make the final image. For me, when I first started to learn shaders I found it helped me make better textures. Knowing how everything worked under the hood helped me understand how to…