Energy preserving ggx?

[thebeals]

Is the ggx brdf implemented in Vray for Maya energy preserving (not to be mistaken with conserving) in a similar sense as in the below Sony and Dassault papers, specifically as it relates to the distribution of the glossy lobe?

https://fpsunflower.github.io/ckulla..._slides_v2.pdf
https://dassaultsystemes-technology....l/spec.md.html

When I do simple tests in vray with a white dome and changing the glossiness lower, it does feel that the appearance darkens and does not preserve energy. If it does not preserve energy, is there a way we could simulate the effect or have it implemented in the shader?

[thebeals]

It appears that Arnold may be adding this multiple scattering ability to restore missing energy as well:

https://arnold-rendering.com/2019/03...gh-metals-5-3/

Can we get this functionality in the vray material, if it's not already included?

[vlado]

It's on the "to do" list to look into this, but I don't know when this is coming yet.

Best regards,
Vlado

[thebeals]

Thank you!

[Paul Oblomov]

Vray5 maybe ? Or not... looks pretty.

[Morbid Angel]

This is what's been missing from my life for past 10 years...

[Karol.Osinski]

That is so interesting! Thanks for sharing, I can't wait to read it all this evening haha.

[damaggio]

The ever evolving Vray Mtl ., looking forward to it.