Graph editor's Noise modifier destructive behavior #78565

New Issue

Mihail · 2020-07-03T06:26:51+02:00

Mihail commented

2020-07-03 06:26:51 +02:00

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 442.50

Blender Version
Broken: version: 2.90.0 Alpha, branch: master, commit date: 2020-07-01 20:17, hash: 52b125a790
Worked: None I know. Oldest I tested is 2.79b which have same issue.

Short description of error
In 3D Viewport, when we apply any transform to object/bone's channel which have Noise Modifier in Graph Editor, offset from modifier will be summed with our actual transform if we store result as a keyframe.
Even if we do Zero-Transform and re-enter current frame, actual keyframe will be different than before because of modifier (note that modifier's offset will be re-applied only if we change frame to modified one again).

So its kind of program logic issue, blender do not separate transforms made by user from transforms made by modifiers, which result in unpredictable and destructive workflow if Graph Modifiers are present (at least Noise).
Noise Modifier is very useful and unique feature, but its extremely hard to use it for complex semi-procedural animations because of this issue.
Current behavior is not even helping with baking procedural animations. Actually if we going straight forward "next frame + add keyframe" through entire animation, result will be a mess since every frame change offsets from modifiers will be summed again and again.
Only way to bake such animation I found is [nla.bake ▶Bake Action] with "Overwrite Current Action" enabled (not default), which itself is very tricky and counterintuitively.
It will be much more usable and user friendly if we will have Bake/Apply button in modifiers tab for baking purposes and have possibility to perform transform operations and [auto] keyframing without taking into account the influence of the modifiers.

It may sound like a feature request, because modifier itself is working fine and keyframing itself is working fine, but since together they become "destructive" (last thing user expecting from modifiers) for existing animations I decided to report it as a bug.

Short video of whats happening: https://imgur.com/RffVV13

Exact steps for others to reproduce the error
0. Enable "Auto Keying" in Timeline

Add a transform keyframe for any object/bone
In Graph Editor, add Noise Modifier to transform channel that was keyed
On any frame make zero-transform
Change to this frame again
may repeat steps 3 and 4 many times

**System Information** Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 442.50 **Blender Version** Broken: version: 2.90.0 Alpha, branch: master, commit date: 2020-07-01 20:17, hash: `52b125a790` Worked: None I know. Oldest I tested is 2.79b which have same issue. **Short description of error** In 3D Viewport, when we apply any transform to object/bone's channel which have Noise Modifier in Graph Editor, offset from modifier will be summed with our actual transform if we store result as a keyframe. Even if we do Zero-Transform and re-enter current frame, actual keyframe will be different than before because of modifier (note that modifier's offset will be re-applied only if we change frame to modified one again). So its kind of program logic issue, blender do not separate transforms made by user from transforms made by modifiers, which result in unpredictable and destructive workflow if Graph Modifiers are present (at least Noise). Noise Modifier is very useful and unique feature, but its extremely hard to use it for complex semi-procedural animations because of this issue. Current behavior is not even helping with baking procedural animations. Actually if we going straight forward "next frame + add keyframe" through entire animation, result will be a mess since every frame change offsets from modifiers will be summed again and again. Only way to bake such animation I found is [nla.bake ▶Bake Action] with "Overwrite Current Action" enabled (not default), which itself is very tricky and counterintuitively. It will be much more usable and user friendly if we will have Bake/Apply button in modifiers tab for baking purposes and have possibility to perform transform operations and [auto] keyframing without taking into account the influence of the modifiers. It may sound like a feature request, because modifier itself is working fine and keyframing itself is working fine, but since together they become "destructive" (last thing user expecting from modifiers) for existing animations I decided to report it as a bug. Short video of whats happening: https://imgur.com/RffVV13 **Exact steps for others to reproduce the error** 0. Enable "Auto Keying" in Timeline 1. Add a transform keyframe for any object/bone 2. In Graph Editor, add Noise Modifier to transform channel that was keyed 3. On any frame make zero-transform 4. Change to this frame again may repeat steps 3 and 4 many times

Mihail commented

2020-07-03 06:26:51 +02:00

Added subscriber: @Maonyao

Philipp Oeser commented

2020-07-10 18:12:29 +02:00

Added subscribers: @dr.sybren, @lichtwerk

Philipp Oeser commented

2020-07-10 18:12:29 +02:00

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

Philipp Oeser closed this issue

2020-07-10 18:12:29 +02:00

Philipp Oeser self-assigned this 2020-07-10 18:12:29 +02:00

Philipp Oeser commented

2020-07-10 18:12:29 +02:00

Tbh, I would think this is more on the side of a feature request.
I get the usecase, and it would be a nice thing to add, but this is not the right place for this.

As a workaround, I assume it would be easy to write an py-operator that disables the FCurve modifiers, then adds a keyframe, and enables the modifiers afterwards again.

In regards to baking:

Only way to bake such animation I found is [nla.bake ▶Bake Action] with "Overwrite Current Action" enabled (not default), which itself is very tricky and counterintuitively.
It will be much more usable and user friendly if we will have Bake/Apply button in modifiers tab for baking purposes

Are these working for you?

Key > Sample Keyframes ?
Key > Bake Curve ?

So thanks for the report, but the issue reported here is a request for modified/improved behavior and not a bug in current behavior. Closing as this bug tracker is only for bugs and errors.
For user requests and feedback, please use other channels: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests
For more information on why this isn't considered a bug, visit: https://wiki.blender.org/wiki/Reference/Not_a_bug

Letting @dr.sybren know of this [he knows I like to let requests through my gate :)] but will have to close this report.

@Maonyao : feel free to comment again regarding the baking (or report this separately if there is an issue with this)

Tbh, I would think this is more on the side of a feature request. I get the usecase, and it would be a nice thing to add, but this is not the right place for this. As a workaround, I assume it would be easy to write an py-operator that disables the FCurve modifiers, then adds a keyframe, and enables the modifiers afterwards again. In regards to baking: > Only way to bake such animation I found is [nla.bake ▶Bake Action] with "Overwrite Current Action" enabled (not default), which itself is very tricky and counterintuitively. > It will be much more usable and user friendly if we will have Bake/Apply button in modifiers tab for baking purposes Are these working for you? - `Key` > `Sample Keyframes` ? - `Key` > `Bake Curve` ? So thanks for the report, but the issue reported here is a request for modified/improved behavior and not a bug in current behavior. Closing as this bug tracker is only for bugs and errors. For user requests and feedback, please use other channels: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests For more information on why this isn't considered a bug, visit: https://wiki.blender.org/wiki/Reference/Not_a_bug Letting @dr.sybren know of this [he knows I like to let requests through my gate :)] but will have to close this report. @Maonyao : feel free to comment again regarding the baking (or report this separately if there is an issue with this)

Mihail commented

2020-07-10 19:44:41 +02:00

@lichtwerk ,

Are these working for you?

Key > Sample Keyframes ?

does nothing in this scenario

Key > Bake Curve ?

Hmm 50/50
It bakes noise to curve, but do not create keyframes for further manual adjustments.
In case of nla->bake we will get actual keyframes to work with (should enable two non-default options, "Visual Keying" and "Overwrite Current Action" to cover all cases).
It is also kind of possible to do final bake (before using object in game engine or something) via export to .fbx, since fbx exporter automatically doing nla bake with default settings. Not useful to get editable keyframes in blender since rig setup data loss.

By the way, while I checked this export-import workflow I found another issue with noise modifier.
If we
apply noise to default cube, export it to object1.fbx, optionally may also delete the cube object after this,
then create another object (tested on uv sphere), add initial keyframe (so no actual movement in blender's viewport) and export it as object2.fbx,
in the result in object2.fbx we will have object with animation affected by modifier's offsets from default cube, even if it was deleted! Not sure what is going on. Thing is broken in many ways.

@lichtwerk , > Are these working for you? > - `Key` > `Sample Keyframes` ? does nothing in this scenario > - `Key` > `Bake Curve` ? Hmm 50/50 It bakes noise to curve, but do not create keyframes for further manual adjustments. In case of nla->bake we will get actual keyframes to work with (should enable two non-default options, "Visual Keying" and "Overwrite Current Action" to cover all cases). It is also kind of possible to do final bake (before using object in game engine or something) via export to .fbx, since fbx exporter automatically doing nla bake with default settings. Not useful to get editable keyframes in blender since rig setup data loss. By the way, while I checked this export-import workflow I found another issue with noise modifier. If we apply noise to default cube, export it to object1.fbx, optionally may also delete the cube object after this, then create another object (tested on uv sphere), add initial keyframe (so no actual movement in blender's viewport) and export it as object2.fbx, in the result in object2.fbx we will have object with animation affected by modifier's offsets from default cube, even if it was deleted! Not sure what is going on. Thing is broken in many ways.

Philipp Oeser commented

2020-07-10 21:12:26 +02:00

In #78565#976961, @Maonyao wrote:

Key > Sample Keyframes ?

does nothing in this scenario

seems to do the trick here (keyframes have to be selected)
#78565.webm

By the way, while I checked this export-import workflow I found another issue with noise modifier.

Please report that separately

> In #78565#976961, @Maonyao wrote: >> - `Key` > `Sample Keyframes` ? > does nothing in this scenario seems to do the trick here (keyframes have to be selected) [#78565.webm](https://archive.blender.org/developer/F8684457/T78565.webm) > By the way, while I checked this export-import workflow I found another issue with noise modifier. Please report that separately

Mihail commented

2020-07-11 08:50:18 +02:00

seems to do the trick here (keyframes have to be selected)

Ohh. I was sure that I selected both of them just as tooltip says, but now I checked again and it worked. Sorry for this.
That seems to be even better way to "keyframe noise" than nla bake. Thank you!
Also may try out your idea of python script for temporary disabling fcurve modifiers before saving a keyframe.

Please report that separately

I'm not sure if this particular bug worth development time. If this happen to me during actual production then I'll make a proper report.

> seems to do the trick here (keyframes have to be selected) Ohh. I was sure that I selected both of them just as tooltip says, but now I checked again and it worked. Sorry for this. That seems to be even better way to "keyframe noise" than nla bake. Thank you! Also may try out your idea of python script for temporary disabling fcurve modifiers before saving a keyframe. > Please report that separately I'm not sure if this particular bug worth development time. If this happen to me during actual production then I'll make a proper report.

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Graph editor's Noise modifier destructive behavior #78565