GPU Cycles (OpenCL) casting shadow where it should be transparent -- if hair is also rendered in the scene #79116

New Issue

Massimo · 2020-07-20T16:31:42+02:00

Massimo commented

2020-07-20 16:31:42 +02:00

System Information
Operating system: Linux-5.4.0-40-generic-x86_64-with-debian-bullseye-sid 64 Bits
Graphics card: AMD Radeon RX 5700 XT (NAVI10, DRM 3.37.0, 5.4.0-40-generic, LLVM 10.0.0) X.Org 4.6 (Core Profile) Mesa 20.0.8

Blender Version
Broken: version: 2.90.0 Alpha, branch: master, commit date: 2020-07-19 21:23, hash: 78e40ad21f
Tried also on 2.83.2 LTS.

Short description of error
Texture casts shadows where it should be transparent.
Works fine if cycles is using the CPU. The error only appears with GPU.

Exact steps for others to reproduce the error

From the attached file, the error already appears as in the image. The checker texture on the left should not cast shadow where it's transparent
if you change the particles from "hair" to "emitter", it works fine.
move back to "hair", the error appears again
select CPU. It works fine

select GPU. The error appears again

transparency_texture.blend

... from a later comment ...

Trying to investigate more, I noticed that the issue is triggered when some hair is being rendered with GPU.
If I do one of these, the issue doesn't appear:

If I exclude rendering of the hair particle system itself on the cube using the "Camera icon" toggle

if I entirely exclude the cube from the rendering, it works too.
I think this is consistent with the behaviour of my first post, as switching particle type from "Hair" to "Emitter" doesn't render any hair.

I add renders of this behaviour too:
↓ Hair particle system toggled as invisible in rendering, works, GPU

↓ Cube with the hair entirely excluded from rendering, works, GPU

**System Information** Operating system: Linux-5.4.0-40-generic-x86_64-with-debian-bullseye-sid 64 Bits Graphics card: AMD Radeon RX 5700 XT (NAVI10, DRM 3.37.0, 5.4.0-40-generic, LLVM 10.0.0) X.Org 4.6 (Core Profile) Mesa 20.0.8 **Blender Version** Broken: version: 2.90.0 Alpha, branch: master, commit date: 2020-07-19 21:23, hash: `78e40ad21f` Tried also on 2.83.2 LTS. **Short description of error** Texture casts shadows where it should be transparent. Works fine if cycles is using the CPU. The error only appears with GPU. **Exact steps for others to reproduce the error** - From the attached file, the error already appears as in the image. The checker texture on the left should not cast shadow where it's transparent - if you change the particles from "hair" to "emitter", it works fine. - move back to "hair", the error appears again - select CPU. It works fine # select GPU. The error appears again [transparency_texture.blend](https://archive.blender.org/developer/F8709097/transparency_texture.blend) ![immagine.png](https://archive.blender.org/developer/F8709098/immagine.png) ![immagine.png](https://archive.blender.org/developer/F8709101/immagine.png) ... from a later comment ... > Trying to investigate more, I noticed that the issue is triggered when some **hair** is being rendered with GPU. > If I do one of these, the issue doesn't appear: > - If I exclude rendering of the hair particle system itself on the cube using the "Camera icon" toggle > - if I entirely exclude the cube from the rendering, it works too. > I think this is consistent with the behaviour of my first post, as switching particle type from "Hair" to "Emitter" doesn't render any hair. > > I add renders of this behaviour too: > ↓ Hair particle system toggled as invisible in rendering, works, GPU > ![no_hair.png](https://archive.blender.org/developer/F8882112/no_hair.png) > ↓ Cube with the hair entirely excluded from rendering, works, GPU > ![no_cube.png](https://archive.blender.org/developer/F8882089/no_cube.png)

Massimo commented

2020-07-20 16:31:42 +02:00

Added subscriber: @rosto

Massimo changed title from ~~Gpu casting shadow where it should be transparent~~ to Gpu Cycles casting shadow where it should be transparent

2020-07-20 16:52:30 +02:00

Richard Antalik commented

2020-07-21 06:38:54 +02:00

Added subscriber: @iss

Richard Antalik commented

2020-07-21 06:38:54 +02:00

Can't reproduce on
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: Radeon RX550/550 Series ATI Technologies Inc. 4.5.13586 Core Profile Context 19.12.2 26.20.15002.61

Can't reproduce on Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: Radeon RX550/550 Series ATI Technologies Inc. 4.5.13586 Core Profile Context 19.12.2 26.20.15002.61

Massimo commented

2020-07-21 10:39:30 +02:00

I add a video of the issue, visible on the left checker plane shadow, hoping it could be helpful
sample_of_transparency_error.mp4

I add a video of the issue, visible on the left checker plane shadow, hoping it could be helpful [sample_of_transparency_error.mp4](https://archive.blender.org/developer/F8711189/sample_of_transparency_error.mp4)

Massimo commented

2020-09-08 11:36:06 +02:00

I tried to reproduce it on Windows on the same computer, to check if it is a OS problem or not.
I can reproduce it on Windows 10 too(I have a dual boot).

I attach a video showing the issue on the same pc, with the same .blend file but on a different operating system
2020-08-03 16-44-07.mkv

I tried to reproduce it on Windows on the same computer, to check if it is a OS problem or not. I can reproduce it on Windows 10 too(I have a dual boot). I attach a video showing the issue on the same pc, with the same .blend file but on a different operating system [2020-08-03 16-44-07.mkv](https://archive.blender.org/developer/F8853747/2020-08-03_16-44-07.mkv)

Germano Cavalcante commented

2020-09-11 15:44:35 +02:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2020-09-11 15:44:35 +02:00

I also cannot reproduce the problem either in the indicated version or in the last daily build.
Tested on a GPU AMD with OpenCL

Please try the latest daily build: https://builder.blender.org/download/

Go to File → Defaults → Load Factory Settings and then load your file to see if you still can reproduce this issue.

Operating system: Windows-10-10.0.18941 64 Bits
Graphics card: Radeon (TM) RX 480 Graphics ATI Technologies Inc. 4.5.13596 Core Profile Context 20.10.19.02 27.20.1019.2002

I also cannot reproduce the problem either in the indicated version or in the last daily build. Tested on a GPU AMD with OpenCL Please try the latest daily build: https://builder.blender.org/download/ Go to File → Defaults → Load Factory Settings and then load your file to see if you still can reproduce this issue. ____ **Operating system:** Windows-10-10.0.18941 64 Bits **Graphics card:** Radeon (TM) RX 480 Graphics ATI Technologies Inc. 4.5.13596 Core Profile Context 20.10.19.02 27.20.1019.2002

Germano Cavalcante commented

2020-09-14 17:15:33 +02:00

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

Massimo commented

2020-09-15 11:03:45 +02:00

Thank you, here are the results on the latest build 2.91.0 Alpha built on September 14th, hash 26a827f254.

Steps:

I loaded factory settings
as Factory settings resets to CPU only rendering, I selected again my graphics cards in the OpenCL options

Renders

Results:
↓Cpu+gpu rendering, you can see the difference between blocks rendered by CPU and the ones by GPU

↓CPU only, works

↓GPU only, issue still appears

Trying to investigate more, I noticed that the issue is triggered when some hair is being rendered with GPU.
If I do one of these, the issue doesn't appear:

If I exclude rendering of the hair particle system itself on the cube using the "Camera icon" toggle
if I entirely exclude the cube from the rendering, it works too.
I think this is consistent with the behaviour of my first post, as switching particle type from "Hair" to "Emitter" doesn't render any hair.

I add renders of this behaviour too:
↓ Hair particle system toggled as invisible in rendering, works, GPU

↓ Cube with the hair entirely excluded from rendering, works, GPU

Let me know if I can do more troubleshooting

Thank you, here are the results on the latest build 2.91.0 Alpha built on September 14th, hash 26a827f25448. Steps: - I loaded factory settings - as Factory settings resets to CPU only rendering, I selected again my graphics cards in the OpenCL options # Renders Results: ↓Cpu+gpu rendering, you can see the difference between blocks rendered by CPU and the ones by GPU ![cpu_and_gpu.png](https://archive.blender.org/developer/F8882085/cpu_and_gpu.png) ↓CPU only, works ![cpu_only.png](https://archive.blender.org/developer/F8882105/cpu_only.png) ↓GPU only, issue still appears ![gpu_only.png](https://archive.blender.org/developer/F8882092/gpu_only.png) Trying to investigate more, I noticed that the issue is triggered when some **hair** is being rendered with GPU. If I do one of these, the issue doesn't appear: - If I exclude rendering of the hair particle system itself on the cube using the "Camera icon" toggle - if I entirely exclude the cube from the rendering, it works too. I think this is consistent with the behaviour of my first post, as switching particle type from "Hair" to "Emitter" doesn't render any hair. I add renders of this behaviour too: ↓ Hair particle system toggled as invisible in rendering, works, GPU ![no_hair.png](https://archive.blender.org/developer/F8882112/no_hair.png) ↓ Cube with the hair entirely excluded from rendering, works, GPU ![no_cube.png](https://archive.blender.org/developer/F8882089/no_cube.png) Let me know if I can do more troubleshooting

Philipp Oeser commented

2020-09-15 11:23:47 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2020-09-15 11:23:47 +02:00

Changed status from 'Needs User Info' to: 'Needs Developer To Reproduce'

Philipp Oeser commented

2020-09-15 11:23:47 +02:00

Also cannot reproduce

**System Information**
Operating system: Linux-5.8.4-200.fc32.x86_64-x86_64-with-fedora-32-Thirty_Two 64 Bits
Graphics card: GeForce GTX 970M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 450.66
2.91.0 Alpha, branch: master, commit date: 2020-09-13 23:10, hash: `rB0f61b27e93f1`

Also cannot reproduce ``` **System Information** Operating system: Linux-5.8.4-200.fc32.x86_64-x86_64-with-fedora-32-Thirty_Two 64 Bits Graphics card: GeForce GTX 970M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 450.66 2.91.0 Alpha, branch: master, commit date: 2020-09-13 23:10, hash: `rB0f61b27e93f1` ```

Philipp Oeser changed title from ~~Gpu Cycles casting shadow where it should be transparent~~ to GPU Cycles (OpenCL) casting shadow where it should be transparent -- if hair is also rendered in the scene

2020-09-15 11:26:22 +02:00

Aaron Carlisle commented

2021-09-22 01:13:04 +02:00

Added subscriber: @Blendify

Aaron Carlisle commented

2021-09-22 01:13:04 +02:00

Changed status from 'Needs Developer To Reproduce' to: 'Archived'

Aaron Carlisle closed this issue

2021-09-22 01:13:04 +02:00

Aaron Carlisle commented

2021-09-22 01:13:04 +02:00

As a result of the Cycles-x changes in Blender 3.0, OpenCL support for Cycles has been removed and older versions will not receive bug fixes in regard to OpenCL rendering.
This is due to the combination of the limited features, driver bugs, and the stalled OpenCL standard making maintenance too difficult.

Blender is working with hardware vendors to bring back GPU rendering support for AMD and Intel GPUs, using others APIs.
Support for all major GPU vendors is an important goal but this goal might not be met for the upcoming 3.0 release.

Support for AMD cards is already in the works, for updates see #91571.

As a result of the [Cycles-x ](https://code.blender.org/2021/04/cycles-x/) changes in Blender 3.0, OpenCL support for Cycles has been removed and older versions will not receive bug fixes in regard to OpenCL rendering. This is due to the combination of the limited features, driver bugs, and the stalled OpenCL standard making maintenance too difficult. Blender is working with hardware vendors to bring back GPU rendering support for AMD and Intel GPUs, using others APIs. Support for all major GPU vendors is an important goal but this goal might not be met for the upcoming 3.0 release. Support for AMD cards is already in the works, for updates see #91571.

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GPU Cycles (OpenCL) casting shadow where it should be transparent -- if hair is also rendered in the scene #79116

select GPU. The error appears again

Renders