When Fresnel Blending is on, controls the minimum amount of reflection that will not be blended with the Fresnel factor. Diffuse components are blended with the transmissive Fresnel component.
Is the diffuse minimum parameter on the mantra shader a feature for more artistic control ? If left at zero is the Fresnel factor automatically controlling the blend with diffuse ?. Coupled with the diffuse minimum acting as a override ? .
sadly not for artistic control, due to nonphysical nature of Surface Model VOP it's necessary to use it when using fresnel and specular intensity is < 1
because diffuse is blended using transmissive fresnel component which results in values 0-1 so if your reflection is on but Specular intensity is low, like 0.1 then at areas where diffuse is faded to 0 reflection reaches only 0.1 and you'll end up with dark areas due to lost energy even if Conserve Energy is on physically diffuse would be complementing reflection intensity therefore the fresnel blend would result in 0.9-1 range for transmittance since reflection has 0.1-0 range this gets more complex with more components(e.g. refract) and Surface Model is not helping at all
anyway, If I ever have Fresnel on and Specular Intensity < 1 I make sure that Diffuse Minimum is 1-Specular Intensity to compensate the same goes for Refraction Minimum On the other hand when using Fresnel I almost always have Specular Intensity at 1 and therefore keep all …Minimum parameters at 0
