Blinn lobe (blBlnn)
- color: specular coefficient
- color: reflectance
- color: roughness
An implementation of Blinn's modification of the Phong
model, for use as part of an aggregate (smAgg) material.
This modification uses the bisector vector H in a dot
product with the surface normal N, rather than the
light source vector and the specular direction as
Don't really know...