CPU vs CUDA anti-aliasing

[seandunderdale]

I've been doing some quick render comparisons and I've found that I cant get as smooth AA with anything other than CPU rendering. Im on Maya 2018 and Vray 3.6. Ive tweaked the max subdivs and also played with the AA size and filter type. But I always seem to end up with jaggy AA in anything other than CPU. Is there something I should be doing when using anything other than CPU to get smooth edges?

[shaio]

Hi,
what AA filter type do you use? If you're using Gaussian AA filter type you might need to increase the size multiplier to a value bigger than the default which is 2.

[seandunderdale]

I always use Gaussian and often go down to 1.3/1.5 for CPU, but tested this at the default 2.0 for CUDA. Ill test higher numbers and get back to you.

[shaio]

Great, please let me know if you need more information.

[seandunderdale]

Bumping gaussian filter up to 5.0 worked for the AA. I left the CPU render max sub divs at 40 and the noise threshold at 0.01 when I rendered with CUDA, but it came out with noise (it rendered in less than half the time). Do the noise sub divs and noise threshold need to be changed as well as the filter amount to get a similar render smoothness?

[shaio]

No, AFAIK the subdivs and the noise threshold should not be changed and the final image should not be more nosie. I'll make some tests and check with the devs if there is something wrong.
Thank you.

[shaio]

Can you share a screenshot(side by side) or a scene where we can check the noise levels, since testing it on my end look normal?

[seandunderdale]

Yeh no problem. I'll test my settings again and if it's still there I'll sling over a scene or some screens.