topic Re: arnold render CPU and GPU's quality is different? in Maya Forum

arnold render CPU and GPU's quality is different?

tom3401 — Mon, 19 Oct 2020 15:01:20 GMT

Hello. I recently find out that GPU rendering is way faster that using CPU.

However, when I compared both pictures rendered by CPU and GPU, this happened.

CPU rendered

GPU rendered

I thought both rendering works exactly the same, except using different calculation.

Should I try more denoising process? Or is my graphic broken?

I wish to know.

p.s. I'm using geforce RTX 2070 super

Re: arnold render CPU and GPU's quality is different?

Stephen.Blair — Mon, 19 Oct 2020 16:03:41 GMT

The sampling is different on GPU. There's no splitting, so you need higher AA

https://docs.arnoldrenderer.com/x/i4QsBQ

Matching Noise on CPU and GPU

Matching noise can take a little experimentation because Arnold GPU uses Camera (AA) sampling only. We recommend you also use Adaptive sampling. Here are some guidelines:

Set the Max. Camera (AA) in the range of 30 to 50 (depending on the scene, you might go closer to 100). In general, the max samples should be a large value. A large max samples means that the quality is controlled by the noise falling under the threshold, instead of by clamping to the max AA.
Set the Adaptive Threshold to something like 0.015 or 0.02. For a noise-free render, lower the threshold value, maybe even as far as 0.010.
Set the Camera (AA) samples to around 3 or 4. One of the few reasons to go higher with AA is for motion blur. The higher the number of Camera (AA) samples, the less of a speedup you'll get from adaptive sampling.

Re: arnold render CPU and GPU's quality is different?

tom3401 — Mon, 19 Oct 2020 18:27:47 GMT

I tried maximum scale of both camera AA and max.AA

.....and it still has so many grains.....

Should I try something on actual cameras?

Is there any arnold control setup to remove grains in camera attribute editor?

I really wonder.

*due to uncertain process, I'm rendering my image as JPEG sequence.

Re: arnold render CPU and GPU's quality is different?

kenne150 — Thu, 06 May 2021 17:08:55 GMT

I was wondering if you found a fix for this? I was hoping that GPU rendering was a good update, but from what I've encountered, it's trash. 😕 So much for quicker renders.

Re: arnold render CPU and GPU's quality is different?

carlos.come — Sun, 13 Jun 2021 21:13:55 GMT

Did you figure out a solution for this? I'm in the same pickle!

Re: arnold render CPU and GPU's quality is different?

Christoph_Schaedl — Mon, 14 Jun 2021 18:19:37 GMT

Use only 4 samples for AA.

Up the samples in your lights to 2.

Lower the noise treshold.

https://youtube.com/shorts/3_4CpoD9c0o

https://youtu.be/XZfsqJ0_9go