Blender 3.2/Blender 3.1 - Incorrect render of barcelone scene with BVH2 #96165

New Issue

Nikita Sirgienko · 2022-03-04T14:30:29+01:00

Nikita Sirgienko commented

2022-03-04 14:30:29 +01:00

System Information
Operating system: Windows 10/Windows 11
Graphics card: AMD RX 6600 XT, NVIDIA RTX 3070

Blender Version
Broken: reproduced stably for few weeks on latest commits on Blender 3.1 Beta (769ae5c866, blender-v3.1-release, 2022-03-03) and Blender 3.2 Alpha (5eaeb9bd0d, master, 2022-03-04)
Worked: unknown, possible Blender 2.93.8 LTS

Short description of error
GPU rendering backends that make use of BVH2 don't render the pabellon/barcelone scene properly - there are artifacts in GPU render for CUDA and HIP, which are not presented with CPU/Embree or Optix rendering.

Rendered image for visual confirmation:
CPU/Embree - correct:

Optix (NVIDIA 3070) - correct (with the exception of the water):

CUDA (NVIDIA 3070) - incorrect:

HIP (RX 6600 XT) - incorrect:

Exact steps for others to reproduce the error

Get Blender 3.1 Beta or Blender 3.2 Alpha from official blender site (https://builder.blender.org/download/daily/)
Get pabellon demo scenes from official blender site (https://download.blender.org/demo/test/pabellon_barcelona_v1.scene_.zip)
Unzip the archive with scene and textures and open .blend file using Blender 3.1 Beta or Blender 3.2 Alpha binary
Run CPU (or Optix) render and remember how correct result should look like
Run GPU render (CUDA or HIP) and confirm differences from CPU render

**System Information** Operating system: Windows 10/Windows 11 Graphics card: AMD RX 6600 XT, NVIDIA RTX 3070 **Blender Version** Broken: reproduced stably for few weeks on latest commits on Blender 3.1 Beta (769ae5c866f32d7a224c141ed4e3e899a54ec150, blender-v3.1-release, 2022-03-03) and Blender 3.2 Alpha (5eaeb9bd0d4d21ab89f5519bba716c5aedc715fc, master, 2022-03-04) Worked: unknown, possible Blender 2.93.8 LTS **Short description of error** GPU rendering backends that make use of BVH2 don't render the pabellon/barcelone scene properly - there are artifacts in GPU render for CUDA and HIP, which are not presented with CPU/Embree or Optix rendering. Rendered image for visual confirmation: CPU/Embree - correct: ![pabellon_quality_problem_cpu.png](https://archive.blender.org/developer/F12897100/pabellon_quality_problem_cpu.png) Optix (NVIDIA 3070) - correct (with the exception of the water): ![pabellon_quality_problem_optix.png](https://archive.blender.org/developer/F12897120/pabellon_quality_problem_optix.png) CUDA (NVIDIA 3070) - incorrect: ![pabellon_quality_problem_cuda.png](https://archive.blender.org/developer/F12897102/pabellon_quality_problem_cuda.png) HIP (RX 6600 XT) - incorrect: ![pabellon_quality_problem_hip.png](https://archive.blender.org/developer/F12897105/pabellon_quality_problem_hip.png) **Exact steps for others to reproduce the error** 1. Get Blender 3.1 Beta or Blender 3.2 Alpha from official blender site (https://builder.blender.org/download/daily/) 2. Get pabellon demo scenes from official blender site (https://download.blender.org/demo/test/pabellon_barcelona_v1.scene_.zip) 3. Unzip the archive with scene and textures and open .blend file using Blender 3.1 Beta or Blender 3.2 Alpha binary 4. Run CPU (or Optix) render and remember how correct result should look like 5. Run GPU render (CUDA or HIP) and confirm differences from CPU render

Nikita Sirgienko commented

2022-03-04 14:30:29 +01:00

Added subscriber: @Sirgienko

Stefan Werner commented

2022-03-04 14:35:17 +01:00

Added subscriber: @Stefan_Werner

Stefan Werner commented

2022-03-04 14:35:17 +01:00

Increasing the number of transparent render bounces makes CPU and GPU renders match again.

Sergey Sharybin commented

2022-03-04 15:06:47 +01:00

Added subscriber: @Sergey

Sergey Sharybin commented

2022-03-04 15:06:47 +01:00

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

Sergey Sharybin commented

2022-03-04 15:06:47 +01:00

Can confirm the issue.
Also reproducible on 3.0 so it is not really a stopper for 3.1, but still rather annoying issue.

Can confirm the issue. Also reproducible on 3.0 so it is not really a stopper for 3.1, but still rather annoying issue.

Nikita Sirgienko commented

2022-03-04 15:18:50 +01:00

I have rechecked 3.0.1 and indeed it haven't' work there: I have got a misclick when I have tested it first time, so I have run CPU test instead of CUDA.
I have updated description accordingly.

I have rechecked 3.0.1 and indeed it haven't' work there: I have got a misclick when I have tested it first time, so I have run CPU test instead of CUDA. I have updated description accordingly.

Sergey Sharybin commented

2022-03-04 15:27:57 +01:00

@Sirgienko, One thing I forgot to mention in the previous reply. Shouldn't CUDA and Hip labels in the report say "Incorrect"?

Nikita Sirgienko commented

2022-03-04 15:30:27 +01:00

In #96165#1317127, @Sergey wrote:
@Sirgienko, One thing I forgot to mention in the previous reply. Shouldn't CUDA and Hip labels in the report say "Incorrect"?

Yes, they should actually be "incorrect", yes. I have fixed it.

> In #96165#1317127, @Sergey wrote: > @Sirgienko, One thing I forgot to mention in the previous reply. Shouldn't CUDA and Hip labels in the report say "Incorrect"? Yes, they should actually be "incorrect", yes. I have fixed it.

Ray molenkamp commented

2022-03-04 15:47:41 +01:00

Added subscriber: @LazyDodo

Ray molenkamp commented

2022-03-04 15:47:41 +01:00

The water in the optix render seems problematic as well, cuda and hip are pretty close to CPU there but not optix.

Alaska changed title from ~~Blender 3.2/Blender 3.1 - Incorrect CUDA/HIP render of barcelone scene~~ to Blender 3.2/Blender 3.1 - Incorrect render of barcelone scene with BVH2

2022-03-04 23:14:09 +01:00

Alaska commented

2022-03-04 23:14:12 +01:00

Added subscriber: @Alaska

Alaska commented

2022-03-04 23:14:12 +01:00

I just thought I would add an extra thing here. The issue isn't caused by the CUDA/HIP rendering backends, it's caused by BVH2 used by those backends. Hence it is also reproducible on the CPU if you change the backend to BVH2.

If you look at the scene from a different angle, you will notice that transparent objects, like the tree leaves, are much brighter when using BVH2 compared to other BVH's. This might be causing the issue you're experiencing. And if that's the case, then this report is quite similar to #95462 (Partly transparent objects appear to glow in the dark when HDRI environment lighting is present (BVH2/Some GPU rendering backends))

I just thought I would add an extra thing here. The issue isn't caused by the CUDA/HIP rendering backends, it's caused by BVH2 used by those backends. Hence it is also reproducible on the CPU if you change the backend to BVH2. If you look at the scene from a different angle, you will notice that transparent objects, like the tree leaves, are much brighter when using BVH2 compared to other BVH's. This might be causing the issue you're experiencing. And if that's the case, then this report is quite similar to #95462 (Partly transparent objects appear to glow in the dark when HDRI environment lighting is present (BVH2/Some GPU rendering backends))

Raimund Klink commented

2022-03-05 01:06:08 +01:00

Added subscriber: @Raimund58

blender-admin commented

2022-03-08 14:43:48 +01:00

This issue was referenced by 04e89c5b06

This issue was referenced by 04e89c5b06739a9a507942e2a9c67fb59b975600

Sergey Sharybin commented

2022-03-09 10:39:08 +01:00

Changed status from 'Confirmed' to: 'Resolved'

Sergey Sharybin closed this issue

2022-03-09 10:39:08 +01:00

Sergey Sharybin self-assigned this 2022-03-09 10:39:08 +01:00

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Blender 3.2/Blender 3.1 - Incorrect render of barcelone scene with BVH2 #96165