shadow render element issue and envFog mixed with contribution passes

[hombrezoo]

Hello dear Vray Next dev team, thanks for the amazing work you guys are putting to make Vray Next the best GPU rendering solution!!!!.
Been doing a lot of testing lately as we are considering Vray Next for the next project.
But ....

LightSelect Render element is mixing envFog shader with the pass, different from CPU where the envFog element it's independent and lightSelect RE are clean and easy to tweak without affecting the overal luminance in comp. So then decided to put the envFog shader in a separate render Setup layer to have clean lightSelect Render Elements and the atmosphere Render Element as a separate pass but.... not only the rendering times increase on the jobs with no envFog but also....

Shadow Render Element is creating terrible noise and jagged shadows.

Not sure if this has been flagged before, I searched on the forum but haven't found anything yet.

[tanya_to]

Hello! Thank you for the kind words. It would be best if you could send to scene for investigation to tanya.todorova@chaosgroup.com.

[hombrezoo]

Thank you very much for the amazing support.
Sent you the scene already.

P

[tanya_to]

Hello! Thank you for the scene. VRayShadows Render Element is incompatible with Adaptive Lights when rendering in V-Ray GPU and that's the reason for the artifacts. This is a known limitation. Regarding the difference in V-RayLightSelect between CPU and GPU rendering, I haven't managed to replicate it. Can you elaborate on this?

[hombrezoo]

Hello Tanya, thanks so much for the explanation. Didn't know how adaptive light was actually working until now. One more thing, the shadow noise is translating into the rbg and general light passes which I hadn't noticed until I disabled GI. Is there a way this can be minimized or should I just forget about using adaptive lighting entirely for now?
Using "uniform probabilistic" and "full evaluation" get rid of the artifacts but they create a lot of grain noise plus they make the render slower.
Can we add Adaptive light to the VrayNext wish list, please .

Regarding the envFog, not sure how it's working now, I used to have some weird render outputs that didn't have fog in the lightSelect RE while using CPU, but now they do. By the way I upgraded to VrayNext V 1.1 a few days ago. But to be honest it may have been a mistake on my part, sorry about this.

Thanks again very much.

[tanya_to]

Hi, again. I'm afraid I have not expressed myself clearly in my previous comment. Adaptive lights are only incompatible with Shadow render element and may produce unwanted artefacts there when rendering with gpu. RGB pass and all the other passes should be fine and without artefacts. There is no need to switch to "uniform probabilistic" and "full evaluation". Regarding the noise you can use VRayDenoiser.

[hombrezoo]

Hello Tanya, thanks again for the quick response.
Yeah you are totally righ. I was having a terrible artifact problem with the RGB, light Select, and in general with most of the color related passes, but I found what the problem was.
Some of the models had multiple UV sets but I will be back if I find it was something else.

Thanks again, I'm back on track!!!!