6.1 Insane colours....

[Pixelcon]

I can't share any files today, but maybe tomorrow. In the case that anyone knows what the issue is off the top of their heads and I can set this off again tonight...
Issue not present with CPU version of vray.
6.1 Using recommended driver.

If I disable sharpening and lens effects, the issue is gone, but I can see some really overbright and colourful pixels that must be causing the issue...

[Pixelcon]

Looks like it was carpaintmtl (the original version) causing the overbright pixels.

[hermit.crab]

Very odd. Is Color Clamping active? Post (or send) the scene when you have the chance.

[Pixelcon]

Very odd. Is Color Clamping active? Post (or send) the scene when you have the chance.

It was but some of the pixels were over 100 float. None of my lights were unreasonably intense. I can't get it to reproduce the problem after restarting max, but if it arises again I'll upload the scene.

[nicolas_fuminier]

Hello,

I had a similar problem on one of my recent 4K renders (watch renders).
It also seemed to me that it came from the post effects.
Re-rendering the image a second time corrected the problem. Considering the size of the rendered images, I thought it might be a RAM / VRAM limit reached when applying the post effects.

I can't share this project either and I can't find any trace of this glitch (all the compromised images have been re-rendered and overwritten)

Vray GPU 61000
Max 2023.3
Nvidia drivers not recommended (528.49)

I will update this post if I encounter the problem again

Linked in file my post effect setup.
Denoiser was Nvidia
As far as I remember no clamp (basic GPU render setup)

[Pixelcon]

I have tried re-rendering againa and again but the problem won't reappear. Regarding vram usage, you might be correct as my rendering was crashing often after having rendered a certain amount of frames (I'm guessing this was due to low Vram).

[hermit.crab]

Just so you know, it's a known issue (internal bug-tracker id: VGPU-5884). It occurs when rendering GPU Light cache in RTX mode when with multiple cards. I'll bump its priority.

[Pixelcon]

I only have one card...

[tanya_to]

@Pixelcon Are you using RTX and GPU Light cache? Could you render the scene again several times (low resolution should be fine for replicating the problem)? The VGPU-5884 issue mentioned by hermit.crab happens quite randomly and the colorful pixels usually appear after rendering consecutively.

[nicolas_fuminier]

@Pixelcon Are you using RTX and GPU Light cache? Could you render the scene again several times (low resolution should be fine for replicating the problem)? The VGPU-5884 issue mentioned by hermit.crab happens quite randomly and the colorful pixels usually appear after rendering consecutively.

We are also running with RTX + Light Cache, the problem happened on different computer with different setup (mostly 2x3090 or 1x3090). We have 10 different computer on our local farm.
The intersting point is, this happened on a specific scene, the 4K watch, but not on the others scene we render daily.
I feel like it's mostly come from the complexity / resolution and not specially the number of frame rendered (I've just finish a 400 frames render this night and no issue at all)
I'll see I can provide you the watch scene to dig in.