3.3: Clay renders with GI render faster

[kosso_olli]

Interesting observation I just made. A clay render I was doing was rendering nearly twice as fast.
I don't want to complain, but what is the reason for this? Is it better to render all scenes with GI, because there is no speed hit anymore?

First is with GI, second without.



Regards

Oliver

[LudvikKoutny]

My guess would be brighter shadows = less contrast for adaptive sampler to resolve. It definitely won't be case for all the scenes, but generally in scenes where GI significantly reduces contrast of lighting and therefore overall contrast of the image, it can sometimes speed things up. I myself was very surprised to find that out.

There seems to be also something weird going in with the domelight sampling in recent V-Ray version, looking as if the ray cutoff threshold was very high, and it can sometimes create kind of small "islands of grain" in penumbra areas, that adaptive sampler has then do a lot of work to resolve. I think that may contribute to this behavior as well. It's strange that it affects only domelight though.

[Paul Oblomov]

If ur using lc - then it stores direct lighting by default. You can try to turn it off - then it would be slower