VSE: Animated sound volume not working when referencing scene #70569

New Issue

Andy · 2019-10-05T21:05:27+02:00

Andy commented

2019-10-05 21:05:27 +02:00

System Information
Operating system: Arch Linux
Graphics card: AMD with Mesa driver

Blender Version
Broken: 2.81 Alpha, ab519b91b2, master, 2019-10-04 22:33

Short description of error
I have multiple scenes in one .blend file using the sequencer. In the first scene ("ReferencedScene") I have a sound strip with an animated volume. Playing that scene adjusts the volume as expected. In another scene ("MAIN"), I added the "ReferencedScene" to the Sequencer. Playing the "MAIN" scene does NOT adjust the volume of the sound in "ReferencedScene". Instead, the volume level stays constant.

I expected that the animated volume of the "ReferencedScene" is the same for direct play back as well as when referenced in the "MAIN" scene.

Exact steps for others to reproduce the error

Open the attached file.
Play back "ReferencedScene" with "Space"
Hear the volume of the sound fade to 0.0 and back to 1.0 again
Switch to "MAIN" scene
Play back "MAIN" scene with "Space"
Hear constant volume of sound from "ReferencedScene"

vse-sound-volume-bug.blend

**System Information** Operating system: Arch Linux Graphics card: AMD with Mesa driver **Blender Version** Broken: 2.81 Alpha, ab519b91b2c4, master, 2019-10-04 22:33 **Short description of error** I have multiple scenes in one .blend file using the sequencer. In the first scene ("ReferencedScene") I have a sound strip with an animated volume. Playing that scene adjusts the volume as expected. In another scene ("MAIN"), I added the "ReferencedScene" to the Sequencer. Playing the "MAIN" scene does NOT adjust the volume of the sound in "ReferencedScene". Instead, the volume level stays constant. I expected that the animated volume of the "ReferencedScene" is the same for direct play back as well as when referenced in the "MAIN" scene. **Exact steps for others to reproduce the error** - Open the attached file. - Play back "ReferencedScene" with "Space" - Hear the volume of the sound fade to 0.0 and back to 1.0 again - Switch to "MAIN" scene - Play back "MAIN" scene with "Space" - Hear constant volume of sound from "ReferencedScene" [vse-sound-volume-bug.blend](https://archive.blender.org/developer/F7791451/vse-sound-volume-bug.blend)

Andy commented

2019-10-05 21:05:27 +02:00

Added subscriber: @andy-rs

blender-admin commented

2019-10-05 21:05:27 +02:00

#82059 was marked as duplicate of this issue

Sybren A. Stüvel commented

2020-01-20 12:34:12 +01:00

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

Richard Antalik commented

2021-01-07 11:19:40 +01:00

Added subscribers: @(Deleted), @iss, @zeauro

Richard Antalik commented

2021-01-07 11:45:39 +01:00

Main problem here seems to be that depsgraph doesn't see relationship between 2 scenes. So sound is always played with constant volume.

If I force evaluation in all linked scenes, this still doesn't help, because sound will play with volume that is set in nested scene, but time(current frame) of that scene will not change.
Evaluation of sounds happens before sequencer rendering, so this can not be handled by sequencer.

The logic of time relations between nested scenes must be handled by sequencer though(at least it's code), because strip can be cut and moved in timeline. Though features such non linear playback speed are not supported due to nature of sound implementation, so this is not problem really. It should be enough to pass offset and evaluate at said time

I haven't checked issues with instancing yet. For example if multiple strips reference same scene this may complicate things, I think that instanced scenes will have shared playbach handle. Still I think it would be better to resolve this so scene, that is instanced once will be evaluated correctly

Main problem here seems to be that depsgraph doesn't see relationship between 2 scenes. So sound is always played with constant volume. If I force evaluation in all linked scenes, this still doesn't help, because sound will play with volume that is set in nested scene, but time(current frame) of that scene will not change. Evaluation of sounds happens before sequencer rendering, so this can not be handled by sequencer. The logic of time relations between nested scenes must be handled by sequencer though(at least it's code), because strip can be cut and moved in timeline. Though features such non linear playback speed are not supported due to nature of sound implementation, so this is not problem really. It should be enough to pass offset and evaluate at said time I haven't checked issues with instancing yet. For example if multiple strips reference same scene this may complicate things, I think that instanced scenes will have shared playbach handle. Still I think it would be better to resolve this so scene, that is instanced once will be evaluated correctly

Richard Antalik commented

2021-01-22 02:32:32 +01:00

This issue needs further work on design level as it doesn't fit current design, so I have reclassified it to known issue.
for more information you can see discussion in D10029

This issue needs further work on design level as it doesn't fit current design, so I have reclassified it to known issue. for more information you can see discussion in [D10029](https://archive.blender.org/developer/D10029)

tintwotin commented

2021-10-16 01:22:33 +02:00

Added subscriber: @tintwotin

tintwotin commented

2021-10-16 01:22:33 +02:00

The trouble is that the exposed audio_volume is tied to the scene and not the strip, which also means that animation of that value doesn't show up in the graph editor of the sequencer scene and it is not possible to go to prev/next value of those keys:
{F11153723,size=full}

Also, the animated volume doesn't show up as a strip-drawn f-curve.

In addition to this, is the Volume value is also unreliable. It gets "stuck" not updating when dragging the playhead, but if you hit ctrl+r it updates again for a while.

Exposing the master volume of the linked scene, means that changes in the vse will effect the source material, which should not be possible(imagine changing the source files on hdd). This also means that changes done in the vse to the scene's volume will have effect if the sequencer is switched off for rendering and the 3d scene is rendered instead.

If several strips are referencing the same scene, all of the strips will have the same volume keys. This is also problematic.

{F11162071,size=full}

Maybe it should be considered to add the Volume as a strip property(like the Sound strip), and then override the volume of the linked scene during preview and render.

The trouble is that the exposed audio_volume is tied to the scene and not the strip, which also means that animation of that value doesn't show up in the graph editor of the sequencer scene and it is not possible to go to prev/next value of those keys: {[F11153723](https://archive.blender.org/developer/F11153723/image.png),size=full} Also, the animated volume doesn't show up as a strip-drawn f-curve. In addition to this, is the Volume value is also unreliable. It gets "stuck" not updating when dragging the playhead, but if you hit ctrl+r it updates again for a while. Exposing the master volume of the linked scene, means that changes in the vse will effect the source material, which should not be possible(imagine changing the source files on hdd). This also means that changes done in the vse to the scene's volume will have effect if the sequencer is switched off for rendering and the 3d scene is rendered instead. If several strips are referencing the same scene, all of the strips will have the same volume keys. This is also problematic. {[F11162071](https://archive.blender.org/developer/F11162071/image.png),size=full} Maybe it should be considered to add the Volume as a strip property(like the Sound strip), and then override the volume of the linked scene during preview and render.

Philipp Oeser removed the

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VSE: Animated sound volume not working when referencing scene #70569