highlight variation 1.0

__roughness and __specularhardness

These parameters are used to offset the roughness and specular gains in the FLphong surface shader.

Why this is kind of interesting is because it allows you to have varying size highlights that are controllable from a light, not the surface itself.

__roughness and __specularhardness are setup in your custom light similarly to Pixar's __nonspecular and __nondiffuse variables.