Correlation Visible on Simple Scenes when using the new PMJ sampler #91632

New Issue

William Leeson · 2021-09-23T11:17:29+02:00

William Leeson commented

2021-09-23 11:17:29 +02:00

System Information
Operating system: Linux-5.13.16-200.fc34.x86_64-x86_64-with-glibc2.33 64 Bits
Graphics card: NVIDIA RTX A4000/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 470.57.02

Blender Version
Broken: version: 3.0.0 Alpha, branch: master, commit date: 2021-09-22 23:29, hash: a78d3c5261
Worked: (newest version of Blender that worked as expected)

Short description of error
There appears to be sample correlation in the image when rendering simple scenes. The mushroom scene below exhibits these artefacts

Adaptive sampling off	Adaptive sampling on

Uses Sobol sampler	Uses PMJ sampler

Exact steps for others to reproduce the error
Open the mushroom.blend file and hit F12 to render. Notice the correlation between pixels which make the diffuse mushroom look shiny.
Mushroom.blend

**System Information** Operating system: Linux-5.13.16-200.fc34.x86_64-x86_64-with-glibc2.33 64 Bits Graphics card: NVIDIA RTX A4000/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 470.57.02 **Blender Version** Broken: version: 3.0.0 Alpha, branch: master, commit date: 2021-09-22 23:29, hash: `a78d3c5261` Worked: (newest version of Blender that worked as expected) **Short description of error** There appears to be sample correlation in the image when rendering simple scenes. The mushroom scene below exhibits these artefacts | Adaptive sampling off | Adaptive sampling on | | -- | -- | | ![Adaptive Sampling off.jpg](https://archive.blender.org/developer/F10557566/Adaptive_Sampling_off.jpg) |![Adaptive Sampling on.jpg](https://archive.blender.org/developer/F10557570/Adaptive_Sampling_on.jpg)| | Uses Sobol sampler | Uses PMJ sampler | **Exact steps for others to reproduce the error** Open the mushroom.blend file and hit F12 to render. Notice the correlation between pixels which make the diffuse mushroom look shiny. [Mushroom.blend](https://archive.blender.org/developer/F10558582/Mushroom.blend)

William Leeson self-assigned this 2021-09-23 11:17:29 +02:00

William Leeson commented

2021-09-23 11:17:29 +02:00

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

William Leeson commented

2021-09-23 11:17:29 +02:00

Added subscribers: @leesonw, @brecht, @Sergey, @SteffenD

Philipp Oeser commented

2021-09-23 11:25:47 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-09-23 11:25:47 +02:00

@leesonw : if you are reporting bugs, it might also make sense to use Help > Report a Bug from within blender (or fill out the template https://developer.blender.org/maniphest/task/edit/form/1/).
This makes sure information such as build hash is available here [which might make a difference in future reference].

Could you update your report?

@leesonw : if you are reporting bugs, it might also make sense to use `Help` > `Report a Bug` from within blender (or fill out the template https://developer.blender.org/maniphest/task/edit/form/1/). This makes sure information such as build hash is available here [which might make a difference in future reference]. Could you update your report?

William Leeson commented

2021-09-23 13:11:43 +02:00

Thanks for the suggestion. I have updated the description and used the bug format now.