Regression: black seams in my Cycles bakes (caused by denoising) due to margin pixel extension darkening #94573

New Issue

L. N. · 2022-01-02T13:44:08+01:00

L. N. commented

2022-01-02 13:44:08 +01:00

System Information
Operating system: Windows-10-10.0.19042-SP0 64 Bits
Graphics card: GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 461.92

Blender Version
Broken: version: 3.0.0, branch: master, commit date: 2021-12-02 18:35, hash: f1cca30557
Worked: 2.93.7

Short description of error
I get black seams when I bake textures that I never used to have before upgrading to 3.0. They occur on any corner that I UV as shown here:

Exact steps for others to reproduce the error
Black Seams.rar
UV a mesh with only 1 split on the corners leaving the other sides still attached. Bake a combined texture to 2048x2048 resolution with Cycles. Apply to mesh. Observe the black seams on the corners.
Now open that same file and bake that same mesh in 2.93.7. No black seams. Re-save file in 2.93, and re-open that file in Blender 3.0, and it now bakes without a black seam too.

**System Information** Operating system: Windows-10-10.0.19042-SP0 64 Bits Graphics card: GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 461.92 **Blender Version** Broken: version: 3.0.0, branch: master, commit date: 2021-12-02 18:35, hash: `f1cca30557` Worked: 2.93.7 **Short description of error** I get black seams when I bake textures that I never used to have before upgrading to 3.0. They occur on any corner that I UV as shown here: ![cycles_bake_dark_seam.png](attachments/a6c6b83c-17e1-4605-9d5d-dc46977c44c9) **Exact steps for others to reproduce the error** [Black Seams.rar](https://archive.blender.org/developer/F12785204/Black_Seams.rar) UV a mesh with only 1 split on the corners leaving the other sides still attached. Bake a combined texture to 2048x2048 resolution with Cycles. Apply to mesh. Observe the black seams on the corners. Now open that same file and bake that same mesh in 2.93.7. No black seams. Re-save file in 2.93, and re-open that file in Blender 3.0, and it now bakes without a black seam too.

cycles_bake_dark_seam.png

552 KiB

L. N. commented

2022-01-02 13:44:08 +01:00

Added subscriber: @aintnobody

blender-admin commented

2022-01-02 13:44:08 +01:00

#97808 was marked as duplicate of this issue

Philipp Oeser commented

2022-01-03 10:45:28 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2022-01-03 10:45:28 +01:00

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

Philipp Oeser commented

2022-01-03 10:45:28 +01:00

Can confirm the regressed baked pixel extension on borders.
I think this has been reported before (but cannot find the duplicate atm.)

Can confirm the regressed baked pixel extension on borders. I think this has been reported before (but cannot find the duplicate atm.)

Philipp Oeser commented

2022-01-03 10:53:07 +01:00

It is caused by denoising btw (without it, pixel extension seems to behave better)

Philipp Oeser changed title from ~~Black seams in my Cycles bakes since I upgraded to 3.0~~ to Regression: black seams in my Cycles bakes (caused by denoising) due to margin pixel extension darkening

2022-01-03 10:56:33 +01:00

Brecht Van Lommel commented

2022-01-20 21:36:56 +01:00

Added subscriber: @brecht

Brecht Van Lommel commented

2022-01-20 21:36:56 +01:00

The denoiser is softening the sharp edges, assuming it's noise. Not clear how best to solve this, probably need to extend the baked pass as well with denoising albedo/normal passes in Cycles.

L. N. commented

2022-01-20 23:17:49 +01:00

I hadn't even noticed until Philipp mentioned it that denoising had become available with baking, which is amazing! But yeah, the black seams need to be fixed please, otherwise it's useless. I have to bake with denoising disabled for now. I will be so happy when I can bake denoised textures.

Brecht Van Lommel commented

2022-01-24 17:17:16 +01:00

For reference, relevant OpenImageDenoise discussion:
https://github.com/OpenImageDenoise/oidn/issues/112

For reference, relevant OpenImageDenoise discussion: https://github.com/OpenImageDenoise/oidn/issues/112

L. N. commented

2022-04-13 11:21:46 +02:00

This wasn't fixed in 3.0 - will it ever be addressed ?

Philipp Oeser commented

2022-05-06 12:55:47 +02:00

Added subscribers: @yPodo, @PratikPB2123

Evandro Costa commented

2022-09-05 22:11:20 +02:00

Added subscriber: @EvandroFerreiradaCosta

Evandro Costa commented

2022-09-05 22:11:20 +02:00

In #94573#1292126, @brecht wrote:
Not clear how best to solve this.

I'd assume one simple solution would be to Denoise the bake before extending the margin, this way the margin will be generated from the denoised version, instead of the noisy image that was stretched to generate a margin.

It appears to me that the denoise algorithm doesn't know how to denoise a black streak instead of a black dot (the optix/OID AI was trained only on dot-pattern noise?)... so the solution is to denoise before stretching.

The caveat is when we are baking multiple objects to the same map, which in the current state, the denoise pass happens only after the entirety of it is baked?
It would have to be changed to happen after every bake is completed but before the margin is applied... only then it starts baking the next object.
Or Blender could store the entire noisy bake from multiple objects without generating a margin, and only applies the margin after the final denoise pass... which would also be beneficial because nowadays if you want to bake multiple objects to the same map, the margins are not SMART like in substance painter, a.k.a, later objects being baked start generating margin on top of previous margins/bakes. By generating the margin at the last step, and taking into consideration the other objects islands, blender would avoid generating margins that overlap others. And the problem with margins not being denoised would also be solved... two rabbits for one.

> In #94573#1292126, @brecht wrote: >Not clear how best to solve this. I'd assume one simple solution would be to Denoise the bake before extending the margin, this way the margin will be generated from the denoised version, instead of the noisy image that was stretched to generate a margin. It appears to me that the denoise algorithm doesn't know how to denoise a black streak instead of a black dot (the optix/OID AI was trained only on dot-pattern noise?)... so the solution is to denoise before stretching. The caveat is when we are baking multiple objects to the same map, which in the current state, the denoise pass happens only after the entirety of it is baked? It would have to be changed to happen after every bake is completed but before the margin is applied... only then it starts baking the next object. Or Blender could store the entire noisy bake from multiple objects without generating a margin, and only applies the margin after the final denoise pass... which would also be beneficial because nowadays if you want to bake multiple objects to the same map, the margins are not SMART like in substance painter, a.k.a, later objects being baked start generating margin on top of previous margins/bakes. By generating the margin at the last step, and taking into consideration the other objects islands, blender would avoid generating margins that overlap others. And the problem with margins not being denoised would also be solved... two rabbits for one.

Brecht Van Lommel commented

2022-09-06 15:44:58 +02:00

It's the other way around, we are denoising before extending the margin, which gives discontinuities. Swapping that order may help, but is not trivial in the current code.

L. N. commented

2022-09-06 15:51:13 +02:00

If that helps, I have never had these seam issues when I denoise a baked texture manually in the Compositing tab this way: https://i.gyazo.com/32d625c25caee2e38eb06e65f6377296.png

It only happens if I check the Denoise checkbox to have my bakes be automatically denoised. So whatever the first method does right, would it be possible to apply it to the automatic Denoising ?

If that helps, I have never had these seam issues when I denoise a baked texture manually in the Compositing tab this way: https://i.gyazo.com/32d625c25caee2e38eb06e65f6377296.png It only happens if I check the Denoise checkbox to have my bakes be automatically denoised. So whatever the first method does right, would it be possible to apply it to the automatic Denoising ?

Evandro Costa commented

2022-09-06 22:56:36 +02:00

@aintnobody Maybe it doesn't generate black seams there in the compositor because then it's denoising the image already with a margin present... so this workflow has the margin step happening before the denoise (working in reverse of what I previously though, as corrected by @Brecht... thanks!)
This seems to indicate that denoising after the margin step would indeed be a valid solution... but if it's non trivial as Brecht mentioned, then we are left waiting for newer versions of OIDN to fix this for us.
According to that github discussion linked earlier:
"The "bleeding" artifact is more like ringing, which has been significantly alleviated (but not completely fixed) in recent versions of OIDN."

So maybe someday it will be completely fixed, outside of blender.

@aintnobody Maybe it doesn't generate black seams there in the compositor because then it's denoising the image already with a margin present... so this workflow has the margin step happening before the denoise (working in reverse of what I previously though, as corrected by @Brecht... thanks!) This seems to indicate that denoising after the margin step would indeed be a valid solution... but if it's non trivial as Brecht mentioned, then we are left waiting for newer versions of OIDN to fix this for us. According to that github discussion linked earlier: *"The "bleeding" artifact is more like ringing, which has been significantly alleviated (but not completely fixed) in recent versions of OIDN."* So maybe someday it will be completely fixed, outside of blender.

Jonathan Lampel commented

2022-11-08 22:24:28 +01:00

Added subscriber: @JonathanLampel-4

Philipp Oeser removed the

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Regression: black seams in my Cycles bakes (caused by denoising) due to margin pixel extension darkening #94573