Jumping Smoke #113997

New Issue

Botlog · 2023-10-21T11:34:30+02:00

Botlog commented

2023-10-21 11:34:30 +02:00

System Information
Operating system: Windows-11 22H2 64 Bit
Graphics card: NVIDIA GeForce RTX 3060 Ti/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 537.58

Blender Version
Broken: version: 4.1.0 Alpha, branch: main (modified), commit date: 2023-10-13 01:10, hash: 845f7f6d4411
Broken: All versions I've worked with >=3.64
Worked: None

Short description of error
Smoke simulation has twitches / Smoke 'jumps'.

Exact steps for others to reproduce the error

Create adaptive Domain type 'Gas' including noise (Cache type: Modular, Checked: Is Resumable, Format Volumes: OpenVDB)
Bake both data and noise
Render animation single or multiple times

I don't know exactly how, but suddenly the animation has jump(s) between frames. It happens with all files since I work at this project for a couple of weeks with different builds >=3.64. Sometimes it needs a day until it happens, sometimes it happens on a first render sequence. Then you have to delete the domain and start again plain, what is annoying.

I dont think, it's a problem with the cache. I've copied a cache after baking, when simulation still was fine. I overwrite the whole cache including noise after an issue happens, but with no effect. Still having jump(s) at the same frame(s) as before. Then I just rendered frames around issue events, and the jump was gone. So I would say, the cache is still okay.

I think, it is a math/calculation issue on updating smoke data during long time rendering animations, because static domains haven't that issue. It is a large amount of data. Maybe this is the problem? I would say, it happens later on animations, after hundred or more frames. I've seen up to three jumps on 300 frames.

Seems like quite similar to this four year old reported bug: #69870

To upload a 45GB animation cache makes no sense, so I skip that. You easyly can reproduce it by using the enhanced blend file.

Hereis a video clip that shows an animation with one jump: https://www.youtube.com/watch?v=17DZLFRi_ZI

**System Information** Operating system: Windows-11 22H2 64 Bit Graphics card: NVIDIA GeForce RTX 3060 Ti/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 537.58 **Blender Version** Broken: version: 4.1.0 Alpha, branch: main (modified), commit date: 2023-10-13 01:10, hash: `845f7f6d4411` Broken: All versions I've worked with >=3.64 Worked: None **Short description of error** Smoke simulation has twitches / Smoke 'jumps'. **Exact steps for others to reproduce the error** 1. Create adaptive Domain type 'Gas' including noise (Cache type: Modular, Checked: Is Resumable, Format Volumes: OpenVDB) 2. Bake both data and noise 3. Render animation single or multiple times I don't know exactly how, but suddenly the animation has jump(s) between frames. It happens with all files since I work at this project for a couple of weeks with different builds >=3.64. Sometimes it needs a day until it happens, sometimes it happens on a first render sequence. Then you have to delete the domain and start again plain, what is annoying. I dont think, it's a problem with the cache. I've copied a cache after baking, when simulation still was fine. I overwrite the whole cache including noise after an issue happens, but with no effect. Still having jump(s) at the same frame(s) as before. Then I just rendered frames around issue events, and the jump was gone. So I would say, the cache is still okay. I think, it is a math/calculation issue on updating smoke data during long time rendering animations, because static domains haven't that issue. It is a large amount of data. Maybe this is the problem? I would say, it happens later on animations, after hundred or more frames. I've seen up to three jumps on 300 frames. Seems like quite similar to this four year old reported bug: https://projects.blender.org/blender/blender/issues/69870 To upload a 45GB animation cache makes no sense, so I skip that. You easyly can reproduce it by using the enhanced blend file. Hereis a video clip that shows an animation with one jump: https://www.youtube.com/watch?v=17DZLFRi_ZI

smoke_issue.blend

851 KiB

Botlog added the

labels 2023-10-21 11:34:31 +02:00

Botlog commented

2023-10-22 09:08:13 +02:00

I just rendered that sequence without noise and had no jumps. Seems like Mark Spink was right about the noise four years ago. And it is the same error.

EDIT: I reenabled noise and the jump is there again. Noise (data) definately triggers this error.

I just rendered that sequence without noise and had no jumps. Seems like Mark Spink was right about the noise four years ago. And it is the same error. EDIT: I reenabled noise and the jump is there again. Noise (data) definately triggers this error.

Germano Cavalcante commented

2023-10-23 16:18:49 +02:00

Thanks for the report, but this issue has already been reported before, see:
#69870: Adaptive Domain causing 'twitches' in gas position when noise applied

It also seems related to:
#107876: Blender Mantaflow gas fire and smoke simulation - Adaptive Domain moves problem!
#110455: Smoke Domain Showing Erratically and Incorrectly
#78738: Mantaflow - Enabling "Noise" breaks fast-moving smoke
#79711: Mantaflow: OpenVDB glitches due to Adaptive Domain
#107679: Blender Mantaflow gas fire and smoke simulation - Adaptive Domain problem!
#81017: Mantaflow: Noise doesn't follow smoke

Note that development of the fluid/smoke simulator is no longer active. So there is not much expectation that this will be resolved soon :\

Will merge reports. Please subscribe in #69870 if you want to see further updates

Thanks for the report, but this issue has already been reported before, see: #69870: Adaptive Domain causing 'twitches' in gas position when noise applied It also seems related to: #107876: Blender Mantaflow gas fire and smoke simulation - Adaptive Domain moves problem! #110455: Smoke Domain Showing Erratically and Incorrectly #78738: Mantaflow - Enabling "Noise" breaks fast-moving smoke #79711: Mantaflow: OpenVDB glitches due to Adaptive Domain #107679: Blender Mantaflow gas fire and smoke simulation - Adaptive Domain problem! #81017: Mantaflow: Noise doesn't follow smoke Note that development of the fluid/smoke simulator is no longer active. So there is not much expectation that this will be resolved soon :\ Will merge reports. Please subscribe in #69870 if you want to see further updates

Germano Cavalcante closed this issue

2023-10-23 16:18:51 +02:00

Blender Bot added

and removed

labels 2023-10-23 16:18:53 +02:00

Germano Cavalcante added

Status

Duplicate