Strong emissive materials bleeding through grease pencil objects #94004

New Issue

Matthew Gafford · 2021-12-13T05:24:46+01:00

Matthew Gafford commented

2021-12-13 05:24:46 +01:00

Operating system: Win10 Home 64
Graphics card: rtx3070

Blender Version
Broken: 2.83, 2.90, 2.91, 2.92, 2.93, 3.0, 3.1
Worked: N/A

Exact steps to reproduce the error:

Give default cube an emissive material with strength ~50 or so and put any grease pencil object in front of it in Rendered view. This artifacting carries over into the actual renders.

(I think it's an opacity issue, because creating a duplicate of the grease pencil on top of itself (Array modifier with 0,0,0 offset) covers the emission glitch up.)

Steps to Reproduce

Open .blend file
Render in viewport

Test File:
#94004.blend

Operating system: Win10 Home 64 Graphics card: rtx3070 Blender Version Broken: 2.83, 2.90, 2.91, 2.92, 2.93, 3.0, 3.1 Worked: N/A Exact steps to reproduce the error: Give default cube an emissive material with strength ~50 or so and put any grease pencil object in front of it in Rendered view. This artifacting carries over into the actual renders. (I think it's an opacity issue, because creating a duplicate of the grease pencil on top of itself (Array modifier with 0,0,0 offset) covers the emission glitch up.) **Steps to Reproduce** - Open .blend file - Render in viewport Test File: [#94004.blend](https://archive.blender.org/developer/F12736788/T94004.blend) ![image.png](https://archive.blender.org/developer/F12736026/image.png) ![image.png](https://archive.blender.org/developer/F12736030/image.png)

Matthew Gafford commented

2021-12-13 05:24:46 +01:00

Added subscriber: @AFoxInSpace

Pratik Borhade commented

2021-12-13 12:14:10 +01:00

Added subscriber: @PratikPB2123

Pratik Borhade commented

2021-12-13 12:33:37 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Pratik Borhade commented

2021-12-13 12:33:37 +01:00

Hi, thanks for the report. Please provide simple .blend file.

I am unable to reproduce with this file (Tested on current master, 2.93LTS): #94004.blend

When actually it happens? when you render in viewport?

Hi, thanks for the report. Please provide simple .blend file. I am unable to reproduce with this file (Tested on current master, 2.93LTS): [#94004.blend](https://archive.blender.org/developer/F12736788/T94004.blend) When actually it happens? when you render in viewport?

Matthew Gafford commented

2021-12-13 13:41:13 +01:00

I opened your file, and it does indeed still have the artifacting in viewport as well as the render, in both 2.93.6 and the new 3.0 versions.

I sent this to two other Blender friends (they have rtx 3060 and rtx 3070 cards) and they both see the same artifacts as well, in eevee and cycles.

I opened your file, and it does indeed still have the artifacting in viewport as well as the render, in both 2.93.6 and the new 3.0 versions. I sent this to two other Blender friends (they have rtx 3060 and rtx 3070 cards) and they both see the same artifacts as well, in eevee and cycles. ![image.png](https://archive.blender.org/developer/F12736943/image.png) ![image.png](https://archive.blender.org/developer/F12736960/image.png)

Fen commented

2021-12-13 15:34:19 +01:00

Added subscriber: @chemicalcrux

Fen commented

2021-12-13 15:34:19 +01:00

I can also observe this on my Linux laptop, which is using Intel integrated graphics. I was using a 3.1.0 lite build. The artifacting looks the same.

Pratik Borhade commented

2021-12-14 06:49:12 +01:00

Thanks for testing. Can you folks reproduce this particular issue on pervious versions (2.92, 2.83LTS)?

So far I am not able to repro on my machine (perhaps an issue for specific GPUs only).

System Information

Graphics card : AMD Radeon(TM) 535 ATI Technologies .```

Thanks for testing. Can you folks reproduce this particular issue on pervious versions (2.92, 2.83LTS)? So far I am not able to repro on my machine (perhaps an issue for specific GPUs only). **System Information** ```Operating system : Windows-10-10.0.18362-SP0 64 Bits Graphics card : AMD Radeon(TM) 535 ATI Technologies .```

Philipp Oeser commented

2021-12-23 10:41:09 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-12-23 10:41:09 +01:00

Changed status from 'Needs User Info' to: 'Confirmed'

Philipp Oeser commented

2021-12-23 10:41:09 +01:00

I can repro.

**System Information**
Operating system: Linux-5.13.0-0.rc6.45.fc35.x86_64-x86_64-with-glibc2.34.9000 64 Bits
Graphics card: NVIDIA GeForce GTX 970M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 495.44
version: 3.1.0 Alpha, branch: master, commit date: 2021-12-20 00:37, hash: `rBcc367908cd69`

Seesm broken in all versions down to 2.83.

I can repro. ``` **System Information** Operating system: Linux-5.13.0-0.rc6.45.fc35.x86_64-x86_64-with-glibc2.34.9000 64 Bits Graphics card: NVIDIA GeForce GTX 970M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 495.44 version: 3.1.0 Alpha, branch: master, commit date: 2021-12-20 00:37, hash: `rBcc367908cd69` ``` Seesm broken in all versions down to 2.83.

Evan Wilson commented

2021-12-27 03:22:06 +01:00

Added subscriber: @EAW

Evan Wilson commented

2021-12-27 03:22:06 +01:00

In #94004, @AFoxInSpace wrote:
I think it's an opacity issue, because creating a duplicate of the grease pencil on top of itself (Array modifier with 0,0,0 offset) covers the emission glitch up.

Just commenting to note that ANY stroke or fill on top of another seems to negate the issue, as seen in the screenshot of Suzanne in front of the cube.
The sclera (whites of the eyes) doesn't have the artifact due to it being in front of the skin fill.
The right side of the chin, the black outline stroke has the artifact only when it is the single Grease Pencil marking (stroke/fill), and is artifact free where the stroke overlaps the skin shadow stroke or the skin fill stroke.

OS: Windows-10-10.0.19043.1052-SP0 64 Bits
GPU: GeForce GTX 470/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 391.35
version: 3.1.0 Alpha, branch: master, commit date: 2021-12-26 20:08, hash: 20b438d523c9, type: Release
build date: 2021-12-27, 01:45:38

> In #94004, @AFoxInSpace wrote: > I think it's an opacity issue, because creating a duplicate of the grease pencil on top of itself (Array modifier with 0,0,0 offset) covers the emission glitch up. Just commenting to note that *ANY* stroke or fill on top of another seems to negate the issue, as seen in the screenshot of Suzanne in front of the cube. The sclera (whites of the eyes) doesn't have the artifact due to it being in front of the skin fill. The right side of the chin, the black outline stroke has the artifact only when it is the single Grease Pencil marking (stroke/fill), and is artifact free where the stroke overlaps the skin shadow stroke or the skin fill stroke. ![image.png](https://archive.blender.org/developer/F12736026/image.png) ``` OS: Windows-10-10.0.19043.1052-SP0 64 Bits GPU: GeForce GTX 470/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 391.35 version: 3.1.0 Alpha, branch: master, commit date: 2021-12-26 20:08, hash: 20b438d523c9, type: Release build date: 2021-12-27, 01:45:38 ```

Brecht Van Lommel commented

2022-01-20 18:53:30 +01:00

Added subscribers: @fclem, @antoniov, @brecht

Brecht Van Lommel commented

2022-01-20 18:53:30 +01:00

@fclem @antoniov I suppose there is some precision issue where alpha ends up e.g. 0.99 instead of 1.0. Maybe there needs to be some slight rounding up there, either in a shader or when reading back the pixels for the GPU.

Nothing to be fixed in Cycles or the general render pipeline as far as I can tell.

@fclem @antoniov I suppose there is some precision issue where alpha ends up e.g. 0.99 instead of 1.0. Maybe there needs to be some slight rounding up there, either in a shader or when reading back the pixels for the GPU. Nothing to be fixed in Cycles or the general render pipeline as far as I can tell.

Philipp Oeser removed the

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Strong emissive materials bleeding through grease pencil objects #94004