Mantaflow adaptive domain cuts off #72253

New Issue

Felix Holzapfel · 2019-12-07T15:00:55+01:00

Felix Holzapfel commented

2019-12-07 15:00:55 +01:00

System Information
Operating system: Windows
Graphics card: 2080TI

Blender Version
fluid-mantaflow-blender-2.82-0ca44974c97f-windows64

Short description of error

The minimal value for Adaptive domain Threshold is 0.01 that is so hight that the domain is clipping off the smoke simulation

**System Information** Operating system: Windows Graphics card: 2080TI **Blender Version** fluid-mantaflow-blender-2.82-0ca44974c97f-windows64 **Short description of error** The minimal value for Adaptive domain Threshold is 0.01 that is so hight that the domain is clipping off the smoke simulation

Felix Holzapfel commented

2019-12-07 15:00:55 +01:00

Added subscriber: @Wooody

Brecht Van Lommel changed title from ~~Adaptive domain cuts off~~ to Mantaflow adaptive domain cuts off

2019-12-08 14:21:40 +01:00

Sebastián Barschkis was assigned by Brecht Van Lommel

2019-12-08 14:21:40 +01:00

Richard Antalik commented

2020-01-17 00:37:42 +01:00

Added subscriber: @iss

Richard Antalik commented

2020-01-17 00:37:42 +01:00

Changed status from 'Needs Developer To Reproduce' to: 'Confirmed'

Richard Antalik commented

2020-01-17 00:37:42 +01:00

I can imagine situation, where Margin and Add Resolution wouldn't be helpful, but it would help to have .blend file that demonstrates this clearly.

I will confirm this and see if it sticks...

I can imagine situation, where Margin and Add Resolution wouldn't be helpful, but it would help to have .blend file that demonstrates this clearly. I will confirm this and see if it sticks...

Felix Holzapfel commented

2020-01-19 02:57:55 +01:00

Attached you find a .blend file. please simulate to frame 260 in order to see the problem clearly. I know it’s an extreme scenario - it’s for demonstration purposes.error test.blend

Attached you find a .blend file. please simulate to frame 260 in order to see the problem clearly. I know it’s an extreme scenario - it’s for demonstration purposes.[error test.blend](https://archive.blender.org/developer/F8286482/error_test.blend)

Sebastián Barschkis commented

2020-01-21 20:54:10 +01:00

@Wooody In the file the smoke inflow is set to 'Geometry'. Was that intentionally? So the idea is that some of that smoke will get cut off by the adaptive domain too early?

Just clarify the actual issue, can you attach an image or short video showing the bug? Thanks!

@Wooody In the file the smoke inflow is set to 'Geometry'. Was that intentionally? So the idea is that some of that smoke will get cut off by the adaptive domain too early? Just clarify the actual issue, can you attach an image or short video showing the bug? Thanks!

Felix Holzapfel commented

2020-01-22 22:10:43 +01:00

Yes, it was intentional in the first place. I wanted to create one smoke puff since I experienced the clipping there the first time. It should not have any impact which inflow type you use. Yes, the smoke gets cut off to early, when the smoke gets too thin.
At the end of the video you see it.adaptive_domain_error.mp4

Yes, it was intentional in the first place. I wanted to create one smoke puff since I experienced the clipping there the first time. It should not have any impact which inflow type you use. Yes, the smoke gets cut off to early, when the smoke gets too thin. At the end of the video you see it.[adaptive_domain_error.mp4](https://archive.blender.org/developer/F8295544/adaptive_domain_error.mp4)

Andrew Price commented

2020-02-18 07:22:49 +01:00

Added subscriber: @AndrewPrice

Andrew Price commented

2020-02-18 07:22:49 +01:00

Confirming this bug in Blender 2.82. Changing the Threshold doesn't seem to make a difference.
erasing adaptive domain.mp4

Confirming this bug in Blender 2.82. Changing the Threshold doesn't seem to make a difference. [erasing adaptive domain.mp4](https://archive.blender.org/developer/F8346849/erasing_adaptive_domain.mp4)

Andrew Price commented

2020-02-19 00:43:09 +01:00

Here's another example showing how severe it is. Blend File: gas_explosion4.blend

erasing adaptive domain2.mp4

Here's another example showing how severe it is. Blend File: [gas_explosion4.blend](https://archive.blender.org/developer/F8349196/gas_explosion4.blend) [erasing adaptive domain2.mp4](https://archive.blender.org/developer/F8349202/erasing_adaptive_domain2.mp4)

Felix Holzapfel commented

2020-02-19 10:49:08 +01:00

Added subscriber: @Andrew-57

Felix Holzapfel commented

2020-02-19 10:49:08 +01:00

@Andrew-57 Price I found a workaround:
You can set the fuel in the inflow to a high value like 10 and than set the reaction speed to a high value like 3. than rapidly animate the reaction speed to a low value (so there are still flames) so there is a large blast of energy at the start which emits a lot of smoke and isn’t considered empty by the adaptive domain.

Best regards,
Felix Holzapfel

@Andrew-57 Price I found a workaround: You can set the fuel in the inflow to a high value like 10 and than set the reaction speed to a high value like 3. than rapidly animate the reaction speed to a low value (so there are still flames) so there is a large blast of energy at the start which emits a lot of smoke and isn’t considered empty by the adaptive domain. Best regards, Felix Holzapfel

Vitor Boschi commented

2020-02-19 12:05:46 +01:00

Added subscriber: @vitorboschi

Andrew Price commented

2020-02-20 04:53:02 +01:00

@Wooody
I appreciate the workaround, but I don't think this solves the problem. Not only would it instantly make the adaptive domain box huge (thus defeating it's purpose) but that smoke density will appear in the render which I obviously don't want. At the moment it's just easier to turn it off, but that drastically increases bakes.

@Wooody I appreciate the workaround, but I don't think this solves the problem. Not only would it instantly make the adaptive domain box huge (thus defeating it's purpose) but that smoke density will appear in the render which I obviously don't want. At the moment it's just easier to turn it off, but that drastically increases bakes.

Andrew Price commented

2020-02-20 04:57:58 +01:00

Here's another example with viewport Color Mapping set to show Density. This demonstrates that it recognizes the density but ignores it.
density debug.mp4

Here's another example with viewport *Color Mapping* set to show Density. This demonstrates that it recognizes the density but ignores it. [density debug.mp4](https://archive.blender.org/developer/F8352503/density_debug.mp4)

Felix Holzapfel commented

2020-02-20 16:29:58 +01:00

@Andrew-57 Price I found a workaround:
You can set the fuel in the inflow to a high value like 10 and than set the reaction speed to a high value like 3. than rapidly animate the reaction speed to a low value (so there are still flames) so there is a large blast of energy at the start which emits a lot of smoke and isn’t considered empty by the adaptive domain.

This still works only in some situations.

Best regards,
Felix Holzapfel

@Andrew-57 Price I found a workaround: You can set the fuel in the inflow to a high value like 10 and than set the reaction speed to a high value like 3. than rapidly animate the reaction speed to a low value (so there are still flames) so there is a large blast of energy at the start which emits a lot of smoke and isn’t considered empty by the adaptive domain. This still works only in some situations. Best regards, Felix Holzapfel

Nathan commented

2020-02-20 22:03:59 +01:00

Added subscriber: @NathanHodges

Nathan commented

2020-02-20 22:03:59 +01:00

Unfortunately, I also have this issue.

AdaptiveDomainCutoff.mp4

Unfortunately, I also have this issue. [AdaptiveDomainCutoff.mp4](https://archive.blender.org/developer/F8354591/AdaptiveDomainCutoff.mp4)

blender-admin commented

2020-03-09 17:41:22 +01:00

This issue was referenced by ab44b1c9dd

This issue was referenced by ab44b1c9ddc23c6981f7c0dd8dafb522ede04450

blender-admin commented

2020-03-09 17:41:22 +01:00

This issue was referenced by 32fc22db56

This issue was referenced by 32fc22db567904b62e52e0805a672a7d0366bcc5

Sebastián Barschkis commented

2020-03-09 17:49:50 +01:00

Changed status from 'Confirmed' to: 'Resolved'

Sebastián Barschkis closed this issue

2020-03-09 17:49:50 +01:00

Sebastián Barschkis commented

2020-03-09 17:50:21 +01:00

Hi everyone! Thanks for all the detailed examples! The reason for the for domain cutting off was the "Threshold" parameter in the "Adaptive Domain" panel. If the value is too high all cells with density values smaller than the threshold value will be considered empty - and therefore cut off.

To fix this issue one has to use a much smaller density threshold. This way cells won't be considered empty so quickly. The fix I just committed (32fc22db56) gives more flexibility in the UI to do just that.

Hi everyone! Thanks for all the detailed examples! The reason for the for domain cutting off was the "Threshold" parameter in the "Adaptive Domain" panel. If the value is too high all cells with density values smaller than the threshold value will be considered empty - and therefore cut off. To fix this issue one has to use a much smaller density threshold. This way cells won't be considered empty so quickly. The fix I just committed (32fc22db5679) gives more flexibility in the UI to do just that.

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Mantaflow adaptive domain cuts off #72253