Constantly battling with issues like these with Vray 5...

[Alex_M]

Please see the screenshot below (image is low-res on purpose). On the left is the original full frame render, on the right is what happened to my rendering when I did a region render. The objects that suddenly turned red after the region render finished are objects that have Object ID of 1 which I use in conjunction with MultiMatte element. The whole image became darker as well.

Anyone else getting issues like these with Vray 5? It's getting a bit frustrating. Almost every day I come across issues like these - darkening in renderings, mixed up channels with objects suddenly glowing in red etc. It always seems to happen when I use denoiser.

[vlado]

I haven’t come across this issue yet. Which denoiser are you using? I will try to reproduce the problem here, but do you think you can get me a scene to vlado@chaosgroup.com ?

Best regards,
Vlado

[Alex_M]

I've just sent you the scene. Thanks for looking into it. To reiterate, I'm almost certain at this point that these issues crop up only when doing region renderings with the Nvidia denoiser and possibly in conjunction with MultiMatte element. Having a light mix render element could play a role too, but I'm not sure about that.

[Alex_M]

Well, this just happened (see below). The multimatte channel spilled over to the RGB channel. It seems that the problem is not strictly related to Nvidia's denoiser and happens in almost any scene. In the screenshot below I used Vray denoiser instead of Nvidia's and multimatte render element.

[vlado]

Yes, I think we figured it out, I hope we will have a fix soon.

Best regards,
Vlado

[Alex_M]

Awesome! Thanks for the quick reaction.

[Pixelcon]

Possibly the same as this? https://forums.chaosgroup.com/forum/...ng-as-expected

[yavor.rubenov]

Possibly the same as this? https://forums.chaosgroup.com/forum/...ng-as-expected

I described how I managed to reproduce it here: https://forums.chaosgroup.com/forum/...69#post1083469
If that is something that might have happened in your workflow - then yes it is the same.