Nvidia Denoiser Color Issue

[yusufcankat_donmez]

Hi to all, there was a similar topic from a few years ago but it was closed without answers so wanted to ask. There is a strange behavior that i can't understand exactly why. I use in my normal workflow Lightmix, VFB color correction layers, and Nvidia denoiser as the preferred denoiser. Mostly I render with a CPU engine. After the render is finished or progressive at the reasonable level I stop the render if it is not the final work and apply denoiser. What I realized is, the denoiser changes the colors and the overall image significantly depending on the level of the denoiser. it looks like denoiser gets false information and blends it with the original image. If I add the denoiser like 0,250 it looks a little different but when I raise the level image gets too much different than I want to see. I can not say where this starts to happen but I believe it has a connection to saved VFB presets. This happens mostly after working with many scenes and applying different presets. But couldn't find a way to use still presets without having this though.

Not directly related but another thing is, I want to apply OCIO profiles but the directory section is locked, and couldn't find a way to enable it.

I use the latest version of Rhino 8 and V-Ray by now on Windows 10.

I would appreciate all suggestions.

Cheers!

[natalia.gruzdova]

Hello yusufcankat_donmez,

Could you please try changing the NVIDIA AI denoiser to default V-Ray Denoiser and let me know if you are still able to reproduce differences that you describe.

In general I would like to note that we advise to use NVIDIA AI Denoiser for Interactive rendering for fast previews. This solution has some advantages and drawbacks compared to the Default V-Ray Denoiser. For example, the NVIDIA AI denoiser performs the denoising faster but is not consistent when denoising render elements. This means that there are differences between the original RGB image and the one reconstructed from render elements that are denoised with the NVIDIA AI denoiser.

Most likely the differences you report is because of these reasons.
You are welcome to find more details in our documentation.