Author Topic: Weak denoising on bump maps  (Read 696 times)

2018-09-13, 15:21:23

Engraff Studio

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Hi everybody,

I don't know if I'm missing something but there seems to be a denoise problem in corona 2.
Image on the left is rendered in Corona 2 and it has a lot more noise than the one on the right which is rendered in Corona 1.74 (same denoise settings, same machine, same time).

Thank you!
Stefan
« Last Edit: 2019-01-15, 10:03:41 by maru »

2018-09-13, 21:58:22
Reply #1

Njen

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I was experiencing the same issue during the beta phase for v2:
https://corona-renderer.com/forum/index.php?topic=17973.msg126877#msg126877

The results I was getting when I posted this are still the same today for the official 2.0 release, in that 1.74 renders with less noise in the same amount of time.
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2018-09-14, 09:55:00
Reply #2

Fluss

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I'm experiencing the same issue with corona 2.0. The denoiser seems to be less effective. I guess it's because they changed the behavior of the denoiser in 2.0 as stated in the changelog :

"Improved denoising of bump maps"

So it should preserve more details now that bump maps are taken into account. But it feels odd as it seems way less consistent and gives this blocky artifact feeling. I'm working on an animation ATM and despite I have not compared it with the previous version, I have the feeling that the noise is way much more visible in 2.0, especially in animations.

It is particularly visible in dark areas as it tends to produce bright dots (see engraff's example image). Definitely something to investigate
« Last Edit: 2018-09-14, 10:01:39 by Fluss »

2018-09-14, 16:54:02
Reply #3

maru

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Hi everybody,

I don't know if I'm missing something but there seems to be a denoise problem in corona 2.
Image on the left is rendered in Corona 2 and it has a lot more noise than the one on the right which is rendered in Corona 1.74 (same denoise settings, same machine, same time).

Thank you!
Stefan

Does your image compare two renders made with the same time limit, pass limit, noise limit, or....?

The noise probably stayed there because of the way denoiser works with bump maps. Do the walls have some bump?

2018-09-14, 18:04:55
Reply #4

Fluss

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Does your image compare two renders made with the same time limit, pass limit, noise limit, or....?


(same denoise settings, same machine, same time).

So I guess it is the new denoiser behavior which is causing the issue.

2018-09-16, 16:35:12
Reply #5

Engraff Studio

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Thank you guys for the info,
I've already switched back to 1.74, at the moment it works fine for me, until the denoiser and the render speed improves in the 2.0 or Corona 3.

Thanks
Stefan

2018-09-17, 15:17:35
Reply #6

maru

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So the two images from the original post were rendered within the same time, right?

2018-09-19, 20:01:05
Reply #7

Engraff Studio

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So the two images from the original post were rendered within the same time, right?

Yes, both images were rendered on a 44 core machine in 1 hour on a 2k rez, noise limit set to 3%. The scene has 15m polys or so.

2018-09-20, 13:48:17
Reply #8

maru

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And is there a bump map used in the wall material?

2018-09-20, 15:30:43
Reply #9

Frood

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noise limit set to 3%.

Why this? It should be zero for testing by time. But of course does not matter if those 3% were not reached during that one hour rendering.

But more important: Do you have a CInfo_SamplingFocus Element by chance for those renders of your initial post? And how high was the denoise amount?


Good Luck


Never underestimate the power of a well placed level one spell.

2018-09-20, 16:06:12
Reply #10

Engraff Studio

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And is there a bump map used in the wall material?

Yes, there is a CoronaNormal map in the bump slot, the wall material is from Corona Material Presets Pro.

Quote
Why this? It should be zero for testing by time. But of course does not matter if those 3% were not reached during that one hour rendering.

But more important: Do you have a CInfo_SamplingFocus Element by chance for those renders of your initial post? And how high was the denoise amount?

The noise limit is set to 3% because I have to render 12-15 images over the night, and the denoise amount was 0.65

2018-09-24, 14:13:55
Reply #11

maru

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And is there a bump map used in the wall material?
Yes, there is a CoronaNormal map in the bump slot, the wall material is from Corona Material Presets Pro.
It's a feature then. The denoiser in v2 is less aggressive on bump maps than in 1.7. You can see a similar example here:
https://corona-renderer.com/comparer/uBPZf0

I don't think we've had any complains about it so far, but if others are experiencing some issues, we will of course consider changing it (e.g. adding a "soft" vs" aggressive" toggle to the ui).
Meanwhile the solution would be probably to allow more passes to render, and only then denoise.

2019-01-14, 21:58:33
Reply #12

mahmoudkeshta

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I have the same problem after using corona 2 and still have this in corona 3. It is very annoying issue because I have noise in almost all renders even I set noise limit to 2.5 or 2.0 which already take long time in rendering. For now I use Ai denoiser which is more soft but it still has some problems in small details. we need a smart solution for this issue like maru said "(e.g. adding a "soft" vs" aggressive" toggle to the ui)".