Smoke Simulation - Wrong smoke behavior if border collision set to "Open" #41787

New Issue

Ruben Musto · 2014-09-11T13:38:42+02:00

Ruben Musto commented

2014-09-11 13:38:42 +02:00

System Information
Window 7 Pro 64bit

Blender Version
2.71

Short description of error
When the border collision of the smoke simulation is set to Open the smoke completely change shape on random frames.

If the border collision is set to Vertically Open it works fine!

Exact steps for others to reproduce the error

Open the file
Set the border collision to Open
Cache the simulation
Play the animation and see the error happening.

N.B. You can also notice the problem by looking at the behavior of the Adaptive Domain: it resize in a wrong way.

To see the correct simulation:

Open the file
Set the border collision to Vertically Open
Cache the simulation
Play the animation and see the right animation.

I can't upload the file because is too big, so here it is: https://dl.dropboxusercontent.com/u/3737004/Car_Drift02.blend.zip

**System Information** Window 7 Pro 64bit **Blender Version** 2.71 **Short description of error** When the border collision of the smoke simulation is set to **Open** the smoke completely change shape on random frames. If the border collision is set to **Vertically Open** it works fine! **Exact steps for others to reproduce the error** - Open the file - Set the border collision to Open - Cache the simulation - Play the animation and see the error happening. N.B. You can also notice the problem by looking at the behavior of the Adaptive Domain: it resize in a wrong way. To see the correct simulation: - Open the file - Set the border collision to **Vertically Open** - Cache the simulation - Play the animation and see the right animation. I can't upload the file because is too big, so here it is: https://dl.dropboxusercontent.com/u/3737004/Car_Drift02.blend.zip

Ruben Musto commented

2014-09-11 13:38:42 +02:00

Changed status to: 'Open'

Ruben Musto commented

2014-09-11 13:38:42 +02:00

Added subscriber: @RubenMusto

Miika Hamalainen was assigned by Sergey Sharybin

2014-09-11 16:03:20 +02:00

Sergey Sharybin commented

2014-09-11 16:03:20 +02:00

Added subscribers: @miikah, @Sergey

Sergey Sharybin commented

2014-09-11 16:03:20 +02:00

@miikah, are you still around to help with smoke stuff?

Lukas Tönne commented

2014-10-08 17:45:16 +02:00

Added subscriber: @LukasTonne

Lukas Tönne commented

2014-10-08 17:45:16 +02:00

I can't see the problem with the test file, it seems to work just as expected. Can you be more specific about what you consider "completely change shape" and "resize in a wrong way"? Maybe attach a screenshot and mark the critical areas?

Lukas Tönne commented

2014-10-08 17:47:30 +02:00

Note about adaptive domain size: The domain tends to fill the entire bounding box after a while, because the smoke just gets thinner and dissipates, but does not entirely dissolve. You can use the dissolve option to make it disappear, a value of 20 or so seems to work quite nicely in this file.

Ruben Musto commented

2014-10-08 22:08:06 +02:00

Hi! This is the behavior I was trying to describe:

as you can see the smoke domain become very big in just one frame (in this case from 2 to 3) and then begin to go smaller again.

I did a couple of try and it doesn't happen alway at the same frame...

Hi! This is the behavior I was trying to describe: ![Screenshot_2014-10-08_21.58.36.png](https://archive.blender.org/developer/F115501/Screenshot_2014-10-08_21.58.36.png) ![Screenshot_2014-10-08_21.59.34.png](https://archive.blender.org/developer/F115503/Screenshot_2014-10-08_21.59.34.png) as you can see the smoke domain become very big in just one frame (in this case from 2 to 3) and then begin to go smaller again. I did a couple of try and it doesn't happen alway at the same frame...

Lukas Tönne commented

2014-10-08 22:38:29 +02:00

To me this is not particularly worrying and doesn't look like a bug. It's just that the smoke still exists further away from the car, even if it's so thin it's not really visible. Like i said, the dissolve option can help clean up the domain where the smoke gets too thin, so the adaptive domain shrinks faster.

There is a slight chance this could also be a windows bug, so i can't really test it (linux).

To me this is not particularly worrying and doesn't look like a bug. It's just that the smoke still exists further away from the car, even if it's so thin it's not really visible. Like i said, the `dissolve` option can help clean up the domain where the smoke gets too thin, so the adaptive domain shrinks faster. There is a slight chance this could also be a windows bug, so i can't really test it (linux).

Julian Eisel commented

2014-11-11 18:33:22 +01:00

Added subscriber: @JulianEisel