I am using MtoA 3.1.2 Arnold Core 5.2.2.0 with Maya 2019.
I found out that SSS is not affected by Arnold Denoice even though other elements like specular, diffuse, transmission are. Here's what I'm working with:
Here are my render settings:
Is it possible to get SSS included in the denoiser with a setting I am missing? I want to save time. I am having to use high samples on SSS to compensate, increasing render time.
A workaround I thought of was to separate out an SSS AOV and denoise that AOV, then recompose the AOV back into the image with After Effects. But that still requires the beauty pass to have SSS in it as far as I know.
Thanks in advance!
Hi Justin,
just preparing the terrain for the Devs, but if you can provide a Log, I think that may be useful for them. I think Info on verbosity level should be enough
Here's the log: SSS_Test_Log.txt
Note that Random Walk v1 is being used for all shaders with SSS.
I tested with Diffusion for SSS and it had a similar result.
That's an old version of arnold. Can you download and install a newer version and see if it's an issue that has since been fixed? https://www.arnoldrenderer.com/arnold/download/
I do not plan to update on my personal computer to avoid risk because I have 4 more weeks left to work on my student film.
However, I do have access to school computers remotely. They run MtoA 4.0.4 Arnold Core 0.6.0.4 Maya 2020 (not the latest version but higher than my personal computer's version). I ran the same render and denoise test on those, but they also output noisy SSS after denoise.
As I search for an answer, I played with the variance setting on the denoiser and 1.5 handled the SSS better, but with artifacts. This isn't optimal because it affects diffuse, specular, etc too strongly. I would prefer SSS to be properly denoised.
The only suggestion I can come up with is that you could try adding the sss_albedo as an AOV and then in the command line noice denoiser you could specify that as a feature buffer instead of diffuse_albedo.
See the "noice custom features" section in https://docs.arnoldrenderer.com/display/A5ARP/5.1.1.0 for the details.
I should add: If you do manage to upgrade to Arnold 5.3 or newer, then you could also try the denoise_albedo as a feature buffer. This might help in both the SSS and non-SSS places.
(I mistyped. The school computers run Arnold version 6.0.4.0)
I gave feature buffers a shot using this script: this python script. I tried using SSS and SSS_Albedo as features to guide denoising. I output their respective AOV's with Guassian and Variance drivers.
In Photoshop, I compared regular denoise vs. feature guided with a difference layer blend, and the results were similar to regular denoise_albedo included the bad SSS noise.
That didn't work, but I did learn how to use Noice through command line!
One thing you can try is increasing the strength of the denoising. It looks like the filter is assuming the sss noise is detail that needs to be kept. In general sss noise should denoise pretty well.