why does denoiser stop working sometimes?

donniekeidic

I have recently been using the denoiser for iray renders. And sometimes it works great, then other times it will just stop working for no apparent reason. The renders aren't dropping to CPU, they just stop denoising sometimes. One time when it stopped working, as a test I removed everything from the scene but the Gen8F character, no clothes, no hair, no environment, nothing but the character and it still woudn't denoise. I had to restart Daz to make it work again. So is it a know bug? Has anyone else faced this issue and figured out the cause?

felis

Does the log have any information?

Help > Troubleshooting > View Log

garrett_3d

What version of DS are you using? I've not experienced this in 4.24.

I can only think it may be that your render is timing out? How long is the render taking and what are your max time settings?

Leana

donniekeidic said:

The renders aren't dropping to CPU, they just stop denoising sometimes. 

Maybe there is enough VRAM for the render but not render + denoising? 

donniekeidic

I'm using DS 4.24.0.3

Renders aren't timing out or going to CPU, I'm purposely using low iterations and just one figure in testing, because I'm basically trying to find efficient ways to handle animations, So max iterations set at 150 iterations, I've also tried lower iterations, and also let it run higher. Makes no difference. Typically I'll know if denoise is working because it will kick in at about 8 iterations (thats the default setting for when it kicks in)

nothing in the log that i can see.

But I was able to make it happen again by simply altering the metalicity of the skin texture (it was at 0, I changed it to .10) then it would no longer denoise after that! I then turned metalicity back to 0. Still wouldn't denoise. Unchecked the GPU under hardware tab and rechecked it to force clear the memory (saw that tip in a different thread). Still wouldn't denoise. Had to restart Daz again. And denoise worked again. I then set metalicity to .10 and denoise still worked, it didn't break this time. So I'm kind of stumped. But it does seems like gloss and metalicity triggers it sometimes but not all the time, for some reason. Because the other time it happened was with a different skin but it had a lot of gloss.

garrett_3d

I'll admit I don't tend to use denoise that much, I prefer to resolve issues using lighting. I have had to use it recently though because of noise on headlamp reflections in a night scene. I didn't experience any issues. I'm on the same DS version as you and I'm using a 12Gb 3080Ti with 64Gb DDR5.

donniekeidic

Leana said:

donniekeidic said:

The renders aren't dropping to CPU, they just stop denoising sometimes. 

Maybe there is enough VRAM for the render but not render + denoising? 

ok, i think Leana is right, I just found this "The denoiser requires 500MB to 2GB of additional VRAM; if the scene exceeds the card's capacity, the denoiser silently disables itself."

so that combined with memory leaks from switching back and forth the skin settings is probably the culprit.