Smoke sim glitch in Cycles #72811

New Issue

caleb morr · 2019-12-30T23:58:33+01:00

caleb morr commented

2019-12-30 23:58:33 +01:00

System Information
Operating system: Windows-10-10.0.17763 64 Bits
Graphics card: GeForce RTX 2080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 441.12

Blender Version
Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-12-04 11:32, hash: f1aa4d18d4
Worked: (optional)

Short description of error
While rendering in cycles my smoke is missing pieces and is very blocky.

Exact steps for others to reproduce the error
Make a quick smoke sim above 60 res or up with adaptive domain (not sure if has to be with a smoke collision object) then add a principled volume to world output and change density to .03 or up. Once a light source is added like a sun and you give it a second to render you can see the weird distortions.

From the file attached just click render and you can see the weird issue

If you want to know what this looks like in a rendered video here is one https://www.youtube.com/watch?v=pOM5uJ_plng&feature=youtu.be

smokeglitch.blend

Ok so I did some more testing and it looks a principled volume smoke sim cant be in the same space as an existing principled volume area (world or just a cube)

**System Information** Operating system: Windows-10-10.0.17763 64 Bits Graphics card: GeForce RTX 2080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 441.12 **Blender Version** Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-12-04 11:32, hash: `f1aa4d18d4` Worked: (optional) **Short description of error** While rendering in cycles my smoke is missing pieces and is very blocky. **Exact steps for others to reproduce the error** Make a quick smoke sim above 60 res or up with adaptive domain (not sure if has to be with a smoke collision object) then add a principled volume to world output and change density to .03 or up. Once a light source is added like a sun and you give it a second to render you can see the weird distortions. From the file attached just click render and you can see the weird issue If you want to know what this looks like in a rendered video here is one https://www.youtube.com/watch?v=pOM5uJ_plng&feature=youtu.be ![mustangdrive100030.png](https://archive.blender.org/developer/F8252498/mustangdrive100030.png) [smokeglitch.blend](https://archive.blender.org/developer/F8252500/smokeglitch.blend) Ok so I did some more testing and it looks a principled volume smoke sim cant be in the same space as an existing principled volume area (world or just a cube)

caleb morr commented

2019-12-30 23:58:33 +01:00

Added subscriber: @CalebMorrison

Jacques Lucke commented

2020-01-14 13:17:38 +01:00

Added subscriber: @JacquesLucke

Jacques Lucke commented

2020-01-14 13:17:38 +01:00

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

Jacques Lucke commented

2020-01-14 13:17:38 +01:00

This file has been created using the old smoke modifier. Are you able to reproduce the issue with the new one in the latest builds?

caleb morr commented

2020-01-14 18:48:21 +01:00

I upgraded to 2.81a and did a quick smoke on the default cube and it was the same

I upgraded to 2.81a and did a quick smoke on the default cube and it was the same ![Capture13.PNG](https://archive.blender.org/developer/F8278140/Capture13.PNG)

Eitan Traurig commented

2020-01-14 18:55:41 +01:00

Added subscriber: @EitanSomething

Eitan Traurig commented

2020-01-14 18:55:41 +01:00

Can you reproduce with the 2.82 experimental build. https://builder.blender.org/download/

caleb morr commented

2020-01-14 22:37:56 +01:00

Heres what I got in 2.82, might be a bit better but still off

![Capture2.PNG](https://archive.blender.org/developer/F8278421/Capture2.PNG) Heres what I got in 2.82, might be a bit better but still off

Jacques Lucke commented

2020-01-15 10:44:45 +01:00

Please provide the updated file, so that we can reproduce it. It should be as simple as possible.

caleb morr commented

2020-01-15 15:45:25 +01:00

smokeerror.blend Just bake the sim and look threw the camera in cycles

[smokeerror.blend](https://archive.blender.org/developer/F8279785/smokeerror.blend) Just bake the sim and look threw the camera in cycles

Jacques Lucke commented

2020-01-15 15:56:13 +01:00

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

Jacques Lucke commented

2020-01-15 15:56:13 +01:00

Added subscriber: @Stefan_Werner

Jacques Lucke commented

2020-01-15 15:56:13 +01:00

Thanks. I can see the issue now. Seems to be related to the fact that you have a volumetric world material. I'm not sure if this is a bug, limitation or just a wrong combination of settings for this kind of scene in Blender.

@Stefan_Werner, do you know the category of the issue in the above file?

Thanks. I can see the issue now. Seems to be related to the fact that you have a volumetric world material. I'm not sure if this is a bug, limitation or just a wrong combination of settings for this kind of scene in Blender. @Stefan_Werner, do you know the category of the issue in the above file?

Jacques Lucke commented

2020-05-27 14:46:12 +02:00

I noticed that the same issue exists when using the new volume object type in master branch with a vdb file.

I noticed that the same issue exists when using the new volume object type in master branch with a vdb file. ![Screen Capture_select-area_20200527144545.png](https://archive.blender.org/developer/F8557782/Screen_Capture_select-area_20200527144545.png)

Stefan Werner commented

2020-05-28 09:36:01 +02:00

Sorry for the late reply.

Two observations:

It does not happen with branched path tracing.
It may look like noise at low sample counts, but does not disappear with higher sample counts.

Sorry for the late reply. Two observations: 1. It does not happen with branched path tracing. 2. It may look like noise at low sample counts, but does not disappear with higher sample counts.

Justin commented

2020-12-19 02:21:17 +01:00

Added subscriber: @jwu420

Philipp Oeser removed the

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Smoke sim glitch in Cycles #72811