So, what's up with Guided Sampling?

johndoe_36eb90b0

I just did some testing and I found that [Guided Sampling] it completely changes scene lighting -- final render ends up ~2/3 EV brighter.

Isn't it supposed to produce the same result, just faster?

Are NVIDIA and Daz even aware of this?

Laurita

I can not confirm this problem. I just tried it and the renders turned out exactly the same.

johndoe_36eb90b0

Laurita said:

I can not confirm this problem. I just tried it and the renders turned out exactly the same.

A few questions:

 - Did you test with the latest beta?
 - Did you use Iray (not CPU rendering)?
 - Was your scene indoors (and by "indoors" I mean in enclosed space such as room with no hidden walls, windows are OK)?
 - Did you use any emissive lights or only built-in light sources?

The most important things seem to be not using sun/sky or HDRI light exclusively (HDRI can contribute, but must not be the main/only light source).

cgidesign

I also did various test with the latest beta and lighting is not significantely changing for me.

But in some cases guided can give the impression of changed light because it focuses the photons like the old portal lights did.

See this thread for an example regarding non guided, guided, caustics:

https://www.daz3d.com/forums/discussion/611416/speed-test-4-21-1-13-beta-vs-26-beta-test-scene-included

johndoe_36eb90b0

@cgidesign I will see if I can create a scene to demonstrate this because I can reliably reproduce it.

Believe me, "it's not an impression of changed light" it's +2/3 EV more light with guided sampling on for me.