Fast sss frustrations

[winberg]

I was very excited when vray got the fast sss, since I never seem to get the results I want with the "old" method..

However I am going slightly mad with the new fast sss too:



Can anyone shed som light on why I get so different results with only change of colors between the two renders?
Is this logical?

max7/RC2

-Tom

[Morbid Angel]

well your shallow color in the second image is brighter, so I think that might be something to do with it.

[winberg]

After reading the online manual, I found that I forgot to blend my sss with a regular vraymtl..

But I would be interested in an explanation on why a light shallow color blocks the sss

-Tom

[vlado]

You can think of the shallow color and deep color as layers on top of each other, similar to how the reflection and diffuse colors are layered in a regular VRayMtl. In VRayMtl, if the reflection color is white, the diffuse color is dimmed. The same is true for the fast sss - the more light is scattered by the shallow layer, the less light reaches the deep layer.

Best regards,
Vlado

[Morbid Angel]

vlado any plans on adopting the brickmap method, as in mr/rman?

[vlado]

vlado any plans on adopting the brickmap method, as in mr/rman?

mental ray does not use brick maps, but a simpler illumination caching scheme. We do not have plans on implementing brick maps either. As for other caching schemes, obviously for 1.5 it's too late, but it may happen in a future update.

Best regards,
Vlado