Viewport render better than final render #81261

New Issue

Julian · 2020-09-28T19:37:27+02:00

Julian commented

2020-09-28 19:37:27 +02:00

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: Radeon (TM) RX 480 Graphics ATI Technologies Inc. 4.5.13587 Core Profile Context 20.2.2 26.20.15019.19000

Blender Version
Broken: version: 2.90.0, branch: master, commit date: 2020-08-31 11:26, hash: 0330d1af29
Worked: (newest version of Blender that worked as expected)
tested in 2.90 and 2.91 Alpha

Short description of error
The viewport render handles shadows much better than the final render.

viewport, no denoise:

Render, no denoise (there are quite big black spots in shadows):

Exact steps for others to reproduce the error
#81261.blend

Open file
Go to rendered view
Render an image ( F12 )
Compare the results

Triaging notes:
This issue exists only when Adaptive sampling is enabled and Min Light Bounces is 0

**System Information** Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: Radeon (TM) RX 480 Graphics ATI Technologies Inc. 4.5.13587 Core Profile Context 20.2.2 26.20.15019.19000 **Blender Version** Broken: version: 2.90.0, branch: master, commit date: 2020-08-31 11:26, hash: `0330d1af29` Worked: (newest version of Blender that worked as expected) tested in 2.90 and 2.91 Alpha **Short description of error** The viewport render handles shadows much better than the final render. viewport, no denoise: ![image.png](https://archive.blender.org/developer/F8933834/image.png) Render, no denoise (there are quite big black spots in shadows): ![image.png](https://archive.blender.org/developer/F8933907/image.png) **Exact steps for others to reproduce the error** [#81261.blend](https://archive.blender.org/developer/F8961559/T81261.blend) - Open file - Go to rendered view - Render an image ( F12 ) - Compare the results Triaging notes: This issue exists only when Adaptive sampling is enabled and Min Light Bounces is 0

Julian commented

2020-09-28 19:37:27 +02:00

Added subscriber: @Julian-4

Diogo Valadares Reis dos Santos commented

2020-09-29 03:39:54 +02:00

Added subscriber: @Diogo_Valadares

Diogo Valadares Reis dos Santos commented

2020-09-29 03:39:54 +02:00

at first I thought this would be caused by the resolution that you where using in render but even after increasing the resolution it still gets a really bad denoising.

the next renders were made with the same sample count and close enough resolutions, the floor had a solidify modifier that is only activated on render, so I deactivated totally it to have the exact same situation for both(If I did not miss anything else)

viewport, denoise

Render. denoise

So I decided to render them without the denoiser, and to my surprise the render one is not only different, its worse, notice how it has some Big black spots intead of a more even noise.

viewport, no denoise:

Render, no denoise:

So the problem is not the denoiser, its something else, so I tried to deactivate adaptative sampling and here is the render result with denoising

If the documentation is right this was not supposed to have such noticeable difference with denoising

and particularly after denoising the result will be almost indistinguishable.

https://docs.blender.org/manual/en/dev/render/cycles/render_settings/sampling.html

it looks like it just glitched in that specific area.

by the way, may be related to the bug, your portal light is pointing to the outside, I guess it should point inside the room, even with adaptative sampling ON the bug does not happen when its turned to the right side

at first I thought this would be caused by the resolution that you where using in render but even after increasing the resolution it still gets a really bad denoising. the next renders were made with the same sample count and close enough resolutions, the floor had a solidify modifier that is only activated on render, so I deactivated totally it to have the exact same situation for both(If I did not miss anything else) viewport, denoise ![image.png](https://archive.blender.org/developer/F8933839/image.png) Render. denoise ![image.png](https://archive.blender.org/developer/F8933914/image.png) So I decided to render them without the denoiser, and to my surprise the render one is not only different, its worse, notice how it has some Big black spots intead of a more even noise. viewport, no denoise: ![image.png](https://archive.blender.org/developer/F8933834/image.png) Render, no denoise: ![image.png](https://archive.blender.org/developer/F8933907/image.png) So the problem is not the denoiser, its something else, so I tried to deactivate adaptative sampling and here is the render result with denoising ![image.png](https://archive.blender.org/developer/F8933932/image.png) If the documentation is right this was not supposed to have such noticeable difference with denoising > and particularly after denoising the result will be almost indistinguishable. https://docs.blender.org/manual/en/dev/render/cycles/render_settings/sampling.html it looks like it just glitched in that specific area. by the way, may be related to the bug, your portal light is pointing to the outside, I guess it should point inside the room, even with adaptative sampling ON the bug does not happen when its turned to the right side

Julian commented

2020-09-29 10:50:54 +02:00

Oh yes I forgot the solidify modifier in this file but I tried it without and it didnt change anything.

I tested with and without portal and I had no difference. So should it always point inside the room? I saw tutorials where the portal points inside and sometimes outside so I thought it doesnt matter.

So adaptive sampling fixed it?

I had a computer monitor in this scene too and the reflection on the screen were also a bit glitchy. I could show you later if it helps.

Oh yes I forgot the solidify modifier in this file but I tried it without and it didnt change anything. I tested with and without portal and I had no difference. So should it always point inside the room? I saw tutorials where the portal points inside and sometimes outside so I thought it doesnt matter. So adaptive sampling fixed it? I had a computer monitor in this scene too and the reflection on the screen were also a bit glitchy. I could show you later if it helps.

Bent Hillerkus commented

2020-09-30 02:23:37 +02:00

Added subscriber: @bent

Diogo Valadares Reis dos Santos commented

2020-09-30 04:09:41 +02:00

I think what caused it was probably the adaptative sampling only, and since that looks like an area where it should be using more samples and not the other way around, it may be an actual bug, tho I can't confirm it.

Alaska commented

2020-09-30 04:16:47 +02:00

Added subscriber: @Alaska

Alaska commented

2020-09-30 04:16:47 +02:00

Sounds like this report is a combination of #75618 (Cycles adaptive sampling gives noisy denoising shadow pass) and #79190 (Cycles PMJ adaptive sampling working poorly with many bounces)

Julian commented

2020-09-30 10:18:48 +02:00

Even with 20000 Samples I have these black spots. What worked for me was to delete the window. But I will test it with this portal thing and adaptive sampling.

Richard Antalik commented

2020-10-06 18:13:25 +02:00

Added subscriber: @iss

Richard Antalik commented

2020-10-06 18:13:25 +02:00

I can confirm this, To me this doesn't look like #75618, because those were spots where no rays were cast to. Here I can see suspiciously black spots, but only in diffuse indirect pass so it may have common cause perhaps.

Clearing render region did not help in my case.

What did help was to increase Min Light Bounces to 2. Perhaps this is somehow different in viewport render?

I can confirm this, To me this doesn't look like #75618, because those were spots where no rays were cast to. Here I can see suspiciously black spots, but only in diffuse indirect pass so it may have common cause perhaps. Clearing render region did not help in my case. What did help was to increase Min Light Bounces to 2. Perhaps this is somehow different in viewport render? ![Untitled.png](https://archive.blender.org/developer/F8961531/Untitled.png)

Richard Antalik changed title from ~~Viewport denoise better than final denoise~~ to Viewport render better than final render

2020-10-06 18:20:30 +02:00

Richard Antalik commented

2020-10-06 18:20:30 +02:00

Changed status from 'Needs Triage' to: 'Confirmed'

Brecht Van Lommel commented

2021-11-05 22:23:06 +01:00

Added subscriber: @brecht

Brecht Van Lommel commented

2021-11-05 22:23:06 +01:00

Changed status from 'Confirmed' to: 'Archived'

Brecht Van Lommel closed this issue

2021-11-05 22:23:06 +01:00

Brecht Van Lommel commented

2021-11-05 22:23:06 +01:00

When adaptive sampling is unable to detect the noise early enough, that leads to structured artifacts. The solution then is to increase the minimum number of samples.

While we will work on improving adaptive sampling to reduce the cases where this happens. This interaction between denoising and adaptive sampling is not a bug, but an indication we can improve our adaptive sampling algorithms further.

Adaptive sampling improvements are tracked in #74581 (Cycles: adaptive sampling improvements).

When adaptive sampling is unable to detect the noise early enough, that leads to structured artifacts. The solution then is to increase the minimum number of samples. While we will work on improving adaptive sampling to reduce the cases where this happens. This interaction between denoising and adaptive sampling is not a bug, but an indication we can improve our adaptive sampling algorithms further. Adaptive sampling improvements are tracked in #74581 (Cycles: adaptive sampling improvements).

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Viewport render better than final render #81261