Cycles produces glowing artifacts around the alpha clipped area of the texture #101810

New Issue

Chingiz Jumagulov · 2022-10-13T21:59:49+02:00

Chingiz Jumagulov commented

2022-10-13 21:59:49 +02:00

System Information
Operating system: Windows 10
Graphics card: Nvidia Geforce 1080, Nvidia Geforce 1070

Blender Version
Broken: 3.3.1
Worked:

Short description of error
Hi! I have stumbled across a weird rendering artifact in Cycles while exporting assets for a project I'm working in. I think it might be a bug, so I thought it might be beneficial to report it. Whenever I assign a .TGA texture that has both RGB and Alpha channels to a Principled Shader and render it with Cycles I have this weird glowing edges effect upon rendering and in the viewport, it works fine with Eevee though.

Here's a screenshot to demonstrate what I'm talking about:

As you can see there's these white glowing edges appearing whenever Cycles is used.

Exact steps for others to reproduce the error
To replicate the issue do the following:
1 - Have a tga Texture with Color and Alpha mask data
2 - Plug the texture to Color and Alpha inputs of the Principled Shader
3 - Turn on Cycles rendering
4 - Observe the weird glowing artefact

P.S. It might be the case with other file formats, or it might be just TGA related, or it might be another reason, I'd appreciate the help on how to get rid of it.

**System Information** Operating system: Windows 10 Graphics card: Nvidia Geforce 1080, Nvidia Geforce 1070 **Blender Version** Broken: 3.3.1 Worked: **Short description of error** Hi! I have stumbled across a weird rendering artifact in Cycles while exporting assets for a project I'm working in. I think it might be a bug, so I thought it might be beneficial to report it. Whenever I assign a .TGA texture that has both RGB and Alpha channels to a Principled Shader and render it with Cycles I have this weird glowing edges effect upon rendering and in the viewport, it works fine with Eevee though. Here's a screenshot to demonstrate what I'm talking about: ![glow around edges_alpha mask.jpg](https://archive.blender.org/developer/F13674608/glow_around_edges_alpha_mask.jpg) As you can see there's these white glowing edges appearing whenever Cycles is used. **Exact steps for others to reproduce the error** To replicate the issue do the following: 1 - Have a tga Texture with Color and Alpha mask data 2 - Plug the texture to Color and Alpha inputs of the Principled Shader 3 - Turn on Cycles rendering 4 - Observe the weird glowing artefact P.S. It might be the case with other file formats, or it might be just TGA related, or it might be another reason, I'd appreciate the help on how to get rid of it.

Chingiz Jumagulov commented

2022-10-13 21:59:49 +02:00

Added subscriber: @MeshVoid

Winona Sharp commented

2022-10-13 22:39:32 +02:00

Added subscriber: @einhander

Winona Sharp commented

2022-10-13 22:39:35 +02:00

Removed subscriber: @einhander

Germano Cavalcante commented

2022-10-13 23:48:52 +02:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2022-10-13 23:48:52 +02:00

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

Germano Cavalcante commented

2022-10-13 23:48:52 +02:00

I cannot reproduce the problem.
I used this image:

If there is anything you can provide to help others to reproduce the problem, be sure to include it.

I cannot reproduce the problem. I used this image: ![xoct20c_shiney.tga](https://archive.blender.org/developer/F13674968/xoct20c_shiney.tga) If there is anything you can provide to help others to reproduce the problem, be sure to include it.

Chingiz Jumagulov commented

2022-10-14 08:22:15 +02:00

For some reason I can produce this reliably all the time.

I made a simple test file with a plane mesh and one tga file with color and alpha data, here's how the same material looks in evee:

Here's how it looks in Cycles on my machine:

Here's the file, maybe inspecting it can help replicate the bug?

bugreport.blend

For some reason I can produce this reliably all the time. I made a simple test file with a plane mesh and one tga file with color and alpha data, here's how the same material looks in evee: ![EEVEE.jpg](https://archive.blender.org/developer/F13676407/EEVEE.jpg) Here's how it looks in Cycles on my machine: ![CYCLES.jpg](https://archive.blender.org/developer/F13676410/CYCLES.jpg) Here's the file, maybe inspecting it can help replicate the bug? [bugreport.blend](https://archive.blender.org/developer/F13676417/bugreport.blend)

Chingiz Jumagulov commented

2022-10-14 08:49:34 +02:00

Interestingly, if I switch to CPU only rendering and tick Open Shading Language option ON, then the white glow effect is gone forever!

CPU render option, OSL ON:

GPU compute:

Interestingly, if I switch to CPU only rendering and tick Open Shading Language option ON, then the white glow effect is gone forever! CPU render option, OSL ON: ![image.png](https://archive.blender.org/developer/F13676498/image.png) GPU compute: ![image.png](https://archive.blender.org/developer/F13676507/image.png)

Chingiz Jumagulov commented

2022-10-14 09:00:15 +02:00

Okay, it has to be related to TGA file format that the inital textures of the asset were stored in. I have converted it to png and there's no glowing effect now.

So I guess it's TGA 24 bit? related bug, that is present in Blender.

Okay, it has to be related to TGA file format that the inital textures of the asset were stored in. I have converted it to png and there's no glowing effect now. ![image.png](https://archive.blender.org/developer/F13676563/image.png) So I guess it's TGA 24 bit? related bug, that is present in Blender.

Germano Cavalcante commented

2022-10-14 20:43:19 +02:00

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

Germano Cavalcante commented

2022-10-14 20:43:19 +02:00

I can't replicate the problem in:
Operating system: Windows-10-10.0.22000-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3060 Laptop GPU/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 516.94

I tried CUDA and OptiX.
Please double-check if the drivers are up to date.
To upgrade to the latest driver, see here for more information: https://docs.blender.org/manual/en/dev/troubleshooting/gpu/index.html

I can't replicate the problem in: Operating system: Windows-10-10.0.22000-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 3060 Laptop GPU/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 516.94 I tried CUDA and OptiX. Please double-check if the drivers are up to date. To upgrade to the latest driver, see here for more information: https://docs.blender.org/manual/en/dev/troubleshooting/gpu/index.html

Evan Wilson commented

2022-10-15 15:15:36 +02:00

Added subscriber: @EAW

Evan Wilson commented

2022-10-15 15:15:36 +02:00

I can reproduce this. This is a duplicate of #99565, I'll merge this report.

Evan Wilson commented

2022-10-15 15:15:56 +02:00

Closed as duplicate of #99565

Evan Wilson closed this issue

2022-10-15 15:15:56 +02:00

Sign in to join this conversation.

No Label

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Cycles produces glowing artifacts around the alpha clipped area of the texture #101810