Is anyone using Iray post denoiser (How to render sharp)
Galaxy
Posts: 562
in The Commons
How to render eyes sharp with post denoiser or everyone is avoiding it like headlamp.
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Personally, my preference is to render with the post denoiser off and do it with a standalone tool afterwards (of which Nvidia's AI Denoiser is an available option, although I generally prefer the results of Intel's OI denoiser).
This is partly because the denoiser uses a fair chunk of VRAM and can make it more likely to drop to CPU (at which point the denoiser won't work anyway), and partly because it's non-destructive - with separate noisy and denoised files, you can mask and adjust the strength of the denoising in an image editor.
If I use the denioser, I sometimes do a spot render of certain areas without the denoiser later and use Photoshop to combine them. For the spot render, set it to render to file in the Tool Settings pane.
Seriously? I had no idea this was the case. Is there documentation on this somewhere? I'm trying to understand why iRay can work with CPU, but not the denoiser.
Denoisers aren't there to sharpen your images. They're for speeding up renders. If fine details are what you're after, denoise backgrounds after rendering normally.
IT does fine with eyes imo. Now hair on the other hand...
Tried with Genesis 8 default eyes? If yes after how many iteration? Worth to mention here that I stopped rendering manually and therefore all iteration not completed.
Example attached first photo with default materials and second photo with increased mess resolution. Clarity increased with artifacts visibility.
I tried with other figures and it looks like Genesis 8 eyes are blurrier than other figures. May be my settings are not correct.
Now after posting the images here looks like sharpness of eyes are acceptable. With post denoiser images are blurry though the fact is my eyes are tuned to compare the eyes with other genesis figures. NOW it looks like artifacts are creating problems.
Edit note: Tried to correct grammatical errors.
I think there might be something wrong with the rest of the settings, because I see artifacts in the skintexture too. Did you compress and replace or reformat all the textures or something like it? The bumpmap/normal also seems to be either missing or wrong. Denoiser should be pretty stable sharp after about 250 rendercycles, I go into the thousands but that's not needed for most people. Don't forget to put sharpening from Gaussian 1.5 into Mitchell 1.0. Gaussian is blurry as heck.
Only for second image. First image is default Genesis 8 materials without any kind of compression.
Great info, thanks. Now I understand why the denoiser doesn't work all the time.
Then it does not matter denoiser on or off because if vram is not sufficient, denoiser is automatically off. Or those are disabling denoising due to "denoiser is occupying vram memory" is a myth only.
@Galaxy "Or those are disabling denoising due to "denoiser is occupying vram memory" is a myth only."
Wouldn't be the first time people acted on a forum post without checking for themselves. Not really a myth, the denoiser will occupy VRAM, it just won't be the cause of a drop to CPU.
@Galaxy The iray denoiser doesn't use the albedo and displacement buffers and it only relies on ai. So it is more an advanced blur than a denoiser. This is why you get blurred images with it. External denoisers can't help either for the same reason because iray can't export the albedo and displacement buffers for them to work properly.
Thus if you want a good and fast denoiser you're out of luck with iray. An option is to go to blender.
https://diffeomorphic.blogspot.com/p/daz-importer-version-14.html
Or use the Intel version, which some say is better than NVidia's. You can use this Windows DragNDrop GUI for both:
https://taosoft.dk/software/freeware/dnden/
I learned some new and useful info, thanks.
The main reason those look that way is because of lighting. The light is rather low here and you know that Iray does not like the dark. It takes more iterations for Iray to render dark scenes. The eyes are odd looking because there is very little information for the denoiser to work on. Another denoiser is not going to magically do better at that picture because albedo can only do so much. But it is very easy to test. Just render them with the denoiser turned off and stop at the same iteration count you did before. Then run through one of the external denoisers. You could try several denoisers, they can be different. Then you will have the answer.
Any denoiser is going to depend on how many pixels have been rendered. The more pixels, the better. The denoiser is also better with non human things, like backgrounds. People are hard.
For your scene, I would add a little light. You can always go back and darken the picture later. I believe if you do this, it will render faster with better detail.
BTW, the Iray denoiser has been updated for Iray 2020 in the new Daz beta, I am not sure if Daz has implemented all of its features yet. But the denoiser is a work in progress and will continue to get updates. So if you tried the Nvidia denoiser before and hated it, you might want to try it again for the beta to see if it has changed any for you. How well it works really depends on what you make, so there is no yes or no answer.