Mantaflow: Animating smoke color affects existing smoke #74763

New Issue

Iago Mota · 2020-03-14T20:12:03+01:00

Iago Mota commented

2020-03-14 20:12:03 +01:00

System Information
Operating system: Windows 10
Graphics card: Nvidia GeForce GTX 650 Ti
Processor: Intel® Core™ i7-3770

Blender Version
Broken: (2.83 Alpha, acab745078)

Short description of error
In Mantaflow, when animating the smoke color in the emitter settings, the changes seem to also affect the smoke that has already been emitted, instead of only affecting the smoke that will be emitted in the next frame.
Color Animation Demo - C.mp4

Exact steps for others to reproduce the error

Add a mesh.
Press F3, type in and select "Quick Smoke", with the mesh selected.
In the emitter settings, animate the smoke color randomly. Or you could set the flow type to fire or fire + smoke and animate the "Fuel" (previously Flame Rate, if I'm not mistaken.)

.blend featured in the video:
BugReport_04_EmitterSettings.blend

**System Information** Operating system: Windows 10 Graphics card: Nvidia GeForce GTX 650 Ti Processor: Intel® Core™ i7-3770 **Blender Version** Broken: (2.83 Alpha, acab7450784a) **Short description of error** In Mantaflow, when animating the smoke color in the emitter settings, the changes seem to also affect the smoke that has already been emitted, instead of only affecting the smoke that will be emitted in the next frame. [Color Animation Demo - C.mp4](https://archive.blender.org/developer/F8406437/Color_Animation_Demo_-_C.mp4) **Exact steps for others to reproduce the error** 1. Add a mesh. 2. Press F3, type in and select "Quick Smoke", with the mesh selected. 3. In the emitter settings, animate the smoke color randomly. Or you could set the flow type to fire or fire + smoke and animate the "Fuel" (previously Flame Rate, if I'm not mistaken.) .blend featured in the video: [BugReport_04_EmitterSettings.blend](https://archive.blender.org/developer/F8406445/BugReport_04_EmitterSettings.blend)

Iago Mota commented

2020-03-14 20:12:03 +01:00

Added subscriber: @Iago-Diogo-de-Vasconcelos-Mota

blender-admin commented

2020-03-14 20:12:03 +01:00

#74819 was marked as duplicate of this issue

Richard Antalik commented

2020-03-17 14:02:23 +01:00

Added subscribers: @sebbas, @iss

Richard Antalik commented

2020-03-17 14:02:23 +01:00

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

Richard Antalik commented

2020-03-17 14:02:23 +01:00

There is report for animating Fuel value already.

I am not sure if animating Smoke Color should not affect existing smoke. @sebbas can you confirm or close this report?

There is report for animating Fuel value already. I am not sure if animating Smoke Color should not affect existing smoke. @sebbas can you confirm or close this report?

Sebastián Barschkis commented

2020-03-17 15:13:31 +01:00

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

Sebastián Barschkis commented

2020-03-17 15:13:31 +01:00

Can confirm the issue. Don't think it's necessarily related to the fuel issue mention in #74078.

Let's keep this as a separate report for now.

Can confirm the issue. Don't think it's necessarily related to the fuel issue mention in #74078. Let's keep this as a separate report for now.

Richard Antalik commented

2020-03-17 16:28:32 +01:00

Added subscriber: @CrossmindStudio

Richard Antalik changed title from ~~Mantaflow: Some emitter settings don't animate properly.~~ to Mantaflow: Animating smoke color affects existing smoke

2020-03-17 16:30:22 +01:00

Georg Bernhard commented

2020-05-23 04:35:15 +02:00

Added subscriber: @gogo

Michael Hermann commented

2020-05-30 16:11:23 +02:00

Added subscriber: @MichaelHermann

Gabriele Guido commented

2020-07-12 18:01:38 +02:00

Added subscriber: @gabriele.guidofoglia

Gabriele Guido commented

2020-07-12 18:16:55 +02:00

Have this and the #74078 been solved in a new Release?

Iago Mota commented

2020-07-13 04:24:48 +02:00

Oh, thanks for reminding me to check this one! Unfortunately, it looks like it got more complicated. In both 2.83.2 and 2.9 Alpha (f319eec881), the bug is gone when it's simulated using Replay type cache (though with several glitches before the first keyframe, probably related to caching). But when it's simulated in Modular or Final/All, the bug is still there. The color changes won't be visible in the viewport, but, if rendered in Cycles, the whole plume of smoke changes color at once, instead of just the newly emitted smoke.
C-Color Anim Bug -02.mp4

In regards to #74078 , it looks like, if Fuel is ever at 0, even if it's only for just a few frames, no fire will appear in the simulation. The smoke will have faster vertical movement as if the fire is there, but the flames won't be visible in the viewport or in Cycles.

Sorry if the information isn't very clear. I'll get back to this as soon as I have a bit more time!

Oh, thanks for reminding me to check this one! Unfortunately, it looks like it got more complicated. In both 2.83.2 and 2.9 Alpha (f319eec88186), the bug is gone when it's simulated using Replay type cache (though with several glitches before the first keyframe, probably related to caching). But when it's simulated in Modular or Final/All, the bug is still there. The color changes won't be visible in the viewport, but, if rendered in Cycles, the whole plume of smoke changes color at once, instead of just the newly emitted smoke. [C-Color Anim Bug -02.mp4](https://archive.blender.org/developer/F8690079/C-Color_Anim_Bug_-02.mp4) In regards to #74078 , it looks like, if Fuel is ever at 0, even if it's only for just a few frames, no fire will appear in the simulation. The smoke will have faster vertical movement as if the fire is there, but the flames won't be visible in the viewport or in Cycles. Sorry if the information isn't very clear. I'll get back to this as soon as I have a bit more time!

Gabriele Guido commented

2020-07-13 09:29:05 +02:00

Ok thanks for the explanation. I wish you good work!💪

Iago Mota commented

2020-07-14 20:09:26 +02:00

Just including a silly test of the Cycles renders. Nothing seems to have changed there, regardless of cache types. (blender 2.90.0 f319eec881 )
C-Color Anim Bug -03.mp4
Emitter Color bug update.blend

Just including a silly test of the Cycles renders. Nothing seems to have changed there, regardless of cache types. (blender 2.90.0 f319eec88186 ) [C-Color Anim Bug -03.mp4](https://archive.blender.org/developer/F8694116/C-Color_Anim_Bug_-03.mp4) [Emitter Color bug update.blend](https://archive.blender.org/developer/F8694120/Emitter_Color_bug_update.blend)

Iago Mota commented

2020-08-05 18:07:37 +02:00

By the way, I'm not encountering this issue anymore in blender-2.91.0 deb76548c1. For me now, the color changes seem to only affect newly emitted smoke, and this also applies to how it's rendered in Cycles. Can anyone confirm this?

By the way, I'm not encountering this issue anymore in blender-2.91.0 deb76548c108. For me now, the color changes seem to only affect newly emitted smoke, and this also applies to how it's rendered in Cycles. Can anyone confirm this?

Richard Antalik commented

2020-08-06 03:25:03 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Richard Antalik closed this issue

2020-08-06 03:25:03 +02:00

Richard Antalik self-assigned this 2020-08-06 03:25:03 +02:00

Richard Antalik commented

2020-08-06 03:25:03 +02:00

Can confirm. So I will close this.

RAM commented

2020-08-06 15:31:32 +02:00

Quite a few times, this and few other bugs were not occurring in daily builds( Beta versions)
hope it is safe to assume that it is resolved for master branch as well and it will land with official release.

Quite a few times, this and few other bugs were not occurring in daily builds( Beta versions) hope it is safe to assume that it is resolved for master branch as well and it will land with official release.

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Mantaflow: Animating smoke color affects existing smoke #74763