Mantaflow (GAS) The simulation does not work correctly when using an object for collisions. #77833

New Issue

Yuriy · 2020-06-13T14:05:57+02:00

Yuriy commented

2020-06-13 14:05:57 +02:00

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 1070 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 446.14

Blender Version
Broken: version: 2.83.0, branch: master, commit date: 2020-06-03 14:38, hash: 211b6c29f7
Worked: 2.82a

Short description of error
The "Collision" effector is installed on the rings. When the rings begin to rotate, the smoke does not move correctly. And in the end, the simulation explodes.
opengl0001-0093.mp4
The same simulation, but made in Blender 2.82a
opengl_2.82a.mp4

Exact steps for others to reproduce the error

Select a torus and bake the particle system.
Choose a domain and bake gas.
Bake Noise.
collision.blend

**System Information** Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: GeForce GTX 1070 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 446.14 **Blender Version** Broken: version: 2.83.0, branch: master, commit date: 2020-06-03 14:38, hash: `211b6c29f7` Worked: 2.82a **Short description of error** The "Collision" effector is installed on the rings. When the rings begin to rotate, the smoke does not move correctly. And in the end, the simulation explodes. [opengl0001-0093.mp4](https://archive.blender.org/developer/F8615381/opengl0001-0093.mp4) The same simulation, but made in Blender 2.82a [opengl_2.82a.mp4](https://archive.blender.org/developer/F8615394/opengl_2.82a.mp4) **Exact steps for others to reproduce the error** 1) Select a torus and bake the particle system. 2) Choose a domain and bake gas. 3) Bake Noise. [collision.blend](https://archive.blender.org/developer/F8643776/collision.blend)

Yuriy commented

2020-06-13 14:05:57 +02:00

Added subscriber: @YuraKharitonow

Richard Antalik commented

2020-06-22 07:27:40 +02:00

Added subscriber: @iss

Richard Antalik commented

2020-06-22 07:27:40 +02:00

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

Richard Antalik commented

2020-06-22 07:27:40 +02:00

This file is very complex. Takes too much time to bake. Is is possible to create simpler example file? Ideally as simple as possible.

Yuriy commented

2020-06-25 17:15:52 +02:00

I can’t repeat the “explosion” of the simulation on the low domain settings.
After running a few low-resolution tests on the domain, I noticed that Noise affected the simulation behavior.
Below is a video without noise.
without_noise0001-0150.mp4
Below is the same simulation, only with noise. Level 1
with_noise0001-0150.mp4
I also found a video on YouTube, in which you can see the "explosion" of the simulation. This happened with Noise enabled.
https://youtu.be/df7_yW_9-M8?t=123

I post the file with my new example.

Select a torus and bake the particle system.
Choose a domain and bake gas.
Bake Noise.
noise.blend

I can’t repeat the “explosion” of the simulation on the low domain settings. After running a few low-resolution tests on the domain, I noticed that Noise affected the simulation behavior. Below is a video without noise. [without_noise0001-0150.mp4](https://archive.blender.org/developer/F8643697/without_noise0001-0150.mp4) Below is the same simulation, only with noise. Level 1 [with_noise0001-0150.mp4](https://archive.blender.org/developer/F8643700/with_noise0001-0150.mp4) I also found a video on YouTube, in which you can see the "explosion" of the simulation. This happened with Noise enabled. https://youtu.be/df7_yW_9-M8?t=123 I post the file with my new example. 1) Select a torus and bake the particle system. 2) Choose a domain and bake gas. 3) Bake Noise. [noise.blend](https://archive.blender.org/developer/F8643709/noise.blend)

Yuriy commented

2020-06-25 17:17:09 +02:00

And one more example with Noise.with_noise0001-0150.mp4

And one more example with Noise.[with_noise0001-0150.mp4](https://archive.blender.org/developer/F8643711/with_noise0001-0150.mp4)

Yuriy commented

2020-06-25 17:54:16 +02:00

It turned out to repeat the unstable simulation at a resolution of 200. No noise.
Fire and smoke should be from the first frame, but they are not. In the end, the simulation is very unstable.
without_noise0001-0150.mp4
1)Select a torus and bake the particle system.
2)Choose a domain and bake gas.
collision.blend

It turned out to repeat the unstable simulation at a resolution of 200. No noise. Fire and smoke should be from the first frame, but they are not. In the end, the simulation is very unstable. [without_noise0001-0150.mp4](https://archive.blender.org/developer/F8643821/without_noise0001-0150.mp4) 1)Select a torus and bake the particle system. 2)Choose a domain and bake gas. [collision.blend](https://archive.blender.org/developer/F8643820/collision.blend)

Yuriy commented

2020-06-25 19:36:06 +02:00

I tried to bake the simulation with a resolution of 150. And I noticed that if the simulation is paused, the simulation will be unstable at the end.
Below is a video in which I paused the simulation twice.
without_noise02.1_with_pauses0001-0150.mp4
And in this video, the simulation is without a pause.
without_noise020001-0150.mp4
Maybe it's a pause. But the noise is clearly baked incorrectly (examples are above).

1)Select a torus and bake the particle system.
2)Choose a domain and bake gas.
collision.blend

I tried to bake the simulation with a resolution of 150. And I noticed that if the simulation is paused, the simulation will be unstable at the end. Below is a video in which I paused the simulation twice. [without_noise02.1_with_pauses0001-0150.mp4](https://archive.blender.org/developer/F8643974/without_noise02.1_with_pauses0001-0150.mp4) And in this video, the simulation is without a pause. [without_noise020001-0150.mp4](https://archive.blender.org/developer/F8643976/without_noise020001-0150.mp4) Maybe it's a pause. But the noise is clearly baked incorrectly (examples are above). 1)Select a torus and bake the particle system. 2)Choose a domain and bake gas. [collision.blend](https://archive.blender.org/developer/F8643982/collision.blend)

Philipp Oeser commented

2020-07-06 11:06:15 +02:00

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

Sebastián Barschkis commented

2020-10-18 23:29:13 +02:00

Added subscriber: @sebbas

Sebastián Barschkis commented

2020-10-18 23:29:13 +02:00

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

Sebastián Barschkis closed this issue

2020-10-18 23:29:13 +02:00

Sebastián Barschkis self-assigned this 2020-10-18 23:29:13 +02:00

Sebastián Barschkis commented

2020-10-18 23:29:13 +02:00

So, there is now a fix in master (663e047102) which resolved similar issues. I was also able to bake the attached scene and got a stable result - I'm therefore calling this issue resolved.

@YuraKharitonow If you have a chance to bake the simulation with the latest master that would be great - just to confirm the fix or prove me wrong :)

So, there is now a fix in master (663e047102) which resolved similar issues. I was also able to bake the attached scene and got a stable result - I'm therefore calling this issue resolved. @YuraKharitonow If you have a chance to bake the simulation with the latest master that would be great - just to confirm the fix or prove me wrong :)

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Mantaflow (GAS) The simulation does not work correctly when using an object for collisions. #77833