VRay Sun Clouds Flickering

[Wigstrand_Digital]

Hi.

I'm rendering a animation with clouds in the sky, and the clouds in the horizon is flickering and acting strange. They are not animated. They also look a bit dark compared to other clouds.

https://replay.dropbox.com/share/pflGTdksTXV0PAmx

Any idea?

[hermit.crab]

Could you simplify the scene (basically leaving the sky) and send it to us so we can take a look?

[Wigstrand_Digital]

Hello Alexander.

I figured out that the "dark clouds" in the horizon is actually created by the Nvidia Denoiser Upscale algorithm.... I used it to speed up my draft renders. So its not a problem when I render the final version. However, it could be nice to solve it anyway.
Can you try it on any scene and confirm that it happens for you to?
I can send my scene if needed.

[hermit.crab]

It is a limitation of the AI Upscaler. The artifacts occur when using a VRaySky or any monotone texture as an environment color and there's clumping of geometry or clouds in your case. Try plugging the VRaySky into a VRayDome light and see if that makes any difference.