Grease Pencil: Erasing/Cutting does not auto-key layers #102623

New Issue

Julien Kaspar · 2022-11-19T18:06:45+01:00

Julien Kaspar commented

2022-11-19 18:06:45 +01:00

System Information
Operating system: Windows-10-10.0.19045-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 516.59

Blender Version
Broken: version: 3.5.0 Alpha, branch: master, commit date: 2022-11-17 22:27, hash: 2c096f17a6
Worked: (newest version of Blender that worked as expected)

Short description of error
Usually whatever edits are done in Edit, Sculpt or Draw mode result in creating a new keyframe, if auto keying is enabled in the timeline.
The issue is that the Eraser brush and the Cutter tool in Draw Mode do not result in auto-keying.
This is easily resulting in lost work.

Note: This is the same issue with the Annotate tools

On the other hand if "Use Additive Drawing" (Snowflake icon) is enabled in the header, erasing will result in correct auto-keying behaviour.
This inconsistency doesn't seem intentional.

Exact steps for others to reproduce the error

Create a grease pencil object
Enable auto-keying in the timeline
Switch to draw mode
Go to the next frame and draw a stroke (It will correctly create a new keyframe)
Go to the next frame and erase part of the stroke (No new keyframe was created)

**System Information** Operating system: Windows-10-10.0.19045-SP0 64 Bits Graphics card: NVIDIA GeForce GTX 1060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 516.59 **Blender Version** Broken: version: 3.5.0 Alpha, branch: master, commit date: 2022-11-17 22:27, hash: `2c096f17a6` Worked: (newest version of Blender that worked as expected) **Short description of error** Usually whatever edits are done in Edit, Sculpt or Draw mode result in creating a new keyframe, if auto keying is enabled in the timeline. The issue is that the Eraser brush and the Cutter tool in Draw Mode do not result in auto-keying. This is easily resulting in lost work. Note: This is the same issue with the Annotate tools On the other hand if "Use Additive Drawing" (Snowflake icon) is enabled in the header, erasing will result in correct auto-keying behaviour. This inconsistency doesn't seem intentional. **Exact steps for others to reproduce the error** - Create a grease pencil object - Enable auto-keying in the timeline - Switch to draw mode - Go to the next frame and draw a stroke (It will correctly create a new keyframe) - Go to the next frame and erase part of the stroke (No new keyframe was created)

Julien Kaspar commented

2022-11-19 18:06:45 +01:00

Added subscriber: @JulienKaspar

Pratik Borhade commented

2022-11-19 19:18:58 +01:00

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

Pratik Borhade commented

2022-11-19 19:19:00 +01:00

Added subscriber: @PratikPB2123

Pratik Borhade commented

2022-11-19 19:26:35 +01:00

Added subscriber: @antoniov

Pratik Borhade commented

2022-11-19 19:26:35 +01:00

@JulienKaspar hi, thanks for the report. Actually this has been reported before and got closed as a design topic: #74608
There is a workaround to generate a keyframe when erasing- enable "additive drawing". see: D7804: GPencil: Create new frame when Erase only if additive drawing is enabled
For cutter tool, it's' still not creating keyframe.
cc @antoniov

@JulienKaspar hi, thanks for the report. Actually this has been reported before and got closed as a design topic: #74608 There is a workaround to generate a keyframe when erasing- `enable "additive drawing"`. see: [D7804: GPencil: Create new frame when Erase only if additive drawing is enabled](https://archive.blender.org/developer/D7804) For cutter tool, it's' still not creating keyframe. cc @antoniov

Antonio Vazquez commented

2022-11-20 11:08:55 +01:00

The cutter is designed to use existing frames, but never creates a new one. In the future we could consider this feature, but now it's a limitation.

Julien Kaspar commented

2022-11-21 12:10:38 +01:00

I see. But I don't understand the reasoning behind this design decision yet and can't find it explained anywhere.
I can only sort of understand the technical reason to do it this way, because erasing by definition is always editing existing strokes.

Issues

IMO the current behavior is a big problem, since it often leads to scenarios where you "accidentally sweep away your footsteps as you walk forward".
Especially with Annotations where there is no way to manually key with I or enable "Additive Drawing".
It's important to acknowledge that it's a common case to erase 'certain parts' first and add to your drawings.

There is no way Blender warns you that erasing and deleting is not considered for auto-keying, even though any other edit will create a keyframe.
It's also not communicated in the UI that "Additive Drawing" works otherwise. It's only mentioned in the Manual as an additional sentence, but excluded from the tooltip.

The proper workflow currently seems to be to use the I shortcut to add a new keyframe manually, or to first do a 'valid' edit that will cause auto-keying to work.
That's not ideal, because it instills a distrust in auto-keying. And it leads to manual extra steps to create a keyframe ... the case that auto-keying was designed to prevent.

My Proposal

If Auto Keying is enabled, always treat erasing and deleting of strokes as if "Additive Drawing" is enabled.
This should be the case for both Annotation and Grease Pencil, in any mode!

This behavior would be more aligned with the purpose of auto-keying and make sure that users can rely on it always creating a new keyframe on any edit.
It's the better compromise in my opinion.

I see. But I don't understand the reasoning behind this design decision yet and can't find it explained anywhere. I can only sort of understand the technical reason to do it this way, because erasing by definition is **always editing existing strokes**. ### Issues IMO the current behavior is a big problem, since it often leads to scenarios where you "accidentally sweep away your footsteps as you walk forward". Especially with Annotations where there is no way to manually key with `I` or enable "Additive Drawing". It's important to acknowledge that it's a common case to erase 'certain parts' first and add to your drawings. There is no way Blender warns you that erasing and deleting is not considered for auto-keying, even though any other edit will create a keyframe. It's also not communicated in the UI that "Additive Drawing" works otherwise. It's only mentioned in the Manual [as an additional sentence](https://docs.blender.org/manual/en/3.5/grease_pencil/modes/draw/introduction.html#drawing-options), but excluded from the tooltip. The proper workflow currently seems to be to use the `I` shortcut to add a new keyframe manually, or to first do a 'valid' edit that will cause auto-keying to work. That's not ideal, because it instills a distrust in auto-keying. And it leads to manual extra steps to create a keyframe ... the case that auto-keying was designed to prevent. ### My Proposal If Auto Keying is enabled, **always** treat erasing and deleting of strokes as if "Additive Drawing" is enabled. This should be the case for both Annotation and Grease Pencil, in any mode! This behavior would be more aligned with the purpose of auto-keying and make sure that users can rely on it always creating a new keyframe on any edit. It's the better compromise in my opinion.

Antonio Vazquez commented

2022-11-21 16:33:36 +01:00

Added subscribers: @mendio, @pepe-school-land

Antonio Vazquez commented

2022-11-21 16:33:36 +01:00

About workflow, I would like to hear @mendio and @pepe-school-land opinion.

In any case, we must not mix GPencil and Annotations... the Annotations are a different tool and is not using the same code for drawing. We split the annotation code some time ago, and our plans for future GP 3.0 is split totally the annotations from GPencil object.

About workflow, I would like to hear @mendio and @pepe-school-land opinion. In any case, we must not mix GPencil and Annotations... the Annotations are a different tool and is not using the same code for drawing. We split the annotation code some time ago, and our plans for future GP 3.0 is split totally the annotations from GPencil object.

Aleš Jelovčan commented

2022-11-22 08:49:49 +01:00

Added subscribers: @Pullup, @frogstomp-4

Aleš Jelovčan commented

2022-11-22 08:49:49 +01:00

I also find myself relying on autokey to produce new frames when erasing and this does lead to accidents.
Actually I want also to bring @Pullup to this discussion regarding his GP transforms tool. I'd like to see more strict respect of autokey in all aspects:

creating new strokes
altering strokes in any way, be it sculpt, vertex paint or deleting geometry

I also find myself relying on autokey to produce new frames when erasing and this does lead to accidents. Actually I want also to bring @Pullup to this discussion regarding his GP transforms tool. I'd like to see more strict respect of autokey in all aspects: - creating new strokes - altering strokes in any way, be it sculpt, vertex paint or deleting geometry

Samuel Bernou commented

2022-11-22 15:45:25 +01:00

Hi, I have to agree with @JulienKaspar, the behavior is mistrusting.
You have to really understand how things work and be constantly aware of what will happens with different actions and contexts, that makes it difficult to predict.

I asked an animator that worked on a lot of GP project, she told that it was particularly misleading in edit mode when deleting stroke (no key is added since it's only auto-keying when modifying or adding stroke).
All other animators I asked agree as well, there is a full consensus on this.

Snowflake (additive draw) is indeed duplicating the keyframe when erasing, but animators don't want to keep previous drawing when they start to draw on a new frame, so they never enable this option.

@frogstomp-4 Thank you for bringing me here. But I think talking about external addons behavior here is out of this discussion scope.
Don't worry though, I agree with you on this point, and this has been on my personal addon's todo list for a while, it's just that respecting autokey is not that easy to implement in Python ^^.

Hi, I have to agree with @JulienKaspar, the behavior is mistrusting. You have to really understand how things work and be constantly aware of what will happens with different actions and contexts, that makes it difficult to predict. I asked an animator that worked on a lot of GP project, she told that it was particularly misleading in edit mode when deleting stroke (no key is added since it's only auto-keying when modifying or adding stroke). All other animators I asked agree as well, there is a full consensus on this. Snowflake (additive draw) is indeed duplicating the keyframe when erasing, but animators don't want to keep previous drawing when they start to draw on a new frame, so they never enable this option. @frogstomp-4 Thank you for bringing me here. But I think talking about external addons behavior here is out of this discussion scope. Don't worry though, I agree with you on this point, and this has been on my personal addon's todo list for a while, it's just that respecting autokey is not that easy to implement in Python ^^.

Matias Mendiola commented

2022-11-22 16:07:38 +01:00

I think the current behavior is legacy from when Grease Pencil didn't use Autokey.
Autokey for Grease Pencil was introduced in Blender 2.93 https:*developer.blender.org/rB6a662ffda836

Whit autokey now fully functional, it make sense to treat any single change on the strokes as a new keyframe.
Whichever tool is used in Draw Mode (Draw, Erase, Tint, cutter) or when deleting points/strokes in Edit Mode.

I think the current behavior is legacy from when Grease Pencil didn't use Autokey. Autokey for Grease Pencil was introduced in Blender 2.93 [https:*developer.blender.org/rB6a662ffda836 ](https:*developer.blender.org/rB6a662ffda836) Whit autokey now fully functional, it make sense to treat any single change on the strokes as a new keyframe. Whichever tool is used in Draw Mode (Draw, Erase, Tint, cutter) or when deleting points/strokes in Edit Mode.

Daniel Martinez Lara commented

2022-11-22 18:38:39 +01:00

Yes, I agree with Matias

Philipp Oeser commented

2022-11-24 14:31:42 +01:00

Added subscriber: @lichtwerk

Antonio Vazquez commented

2022-11-29 12:27:11 +01:00

I have changed the Eraser and now if you have auto-key enabled, a new frame is created.

About Cutter the things are totally different. The problem with Cutter is that needs to find what points need to cut and also is multiframe, so it's not possible (it's possible, but changing all the code of the operator) to detect if need to create the frame or not...also, if you are using multiframe would need to create a lot of frames in the new one. If we duplicate the frame before, we could use the Cutter, don't delete anything but create the frame anyway.

As we are planning GPencil 3.0, IMHO it doesn't worth the complexity to change all the code that surely we are going to deprecate. I would set this as Known Issue.

I have changed the `Eraser` and now if you have `auto-key` enabled, a new frame is created. About `Cutter` the things are totally different. The problem with Cutter is that needs to find what points need to cut and also is multiframe, so it's not possible (it's possible, but changing all the code of the operator) to detect if need to create the frame or not...also, if you are using multiframe would need to create a lot of frames in the new one. If we duplicate the frame before, we could use the `Cutter`, don't delete anything but create the frame anyway. As we are planning GPencil 3.0, IMHO it doesn't worth the complexity to change all the code that surely we are going to deprecate. I would set this as `Known Issue`.

Philipp Oeser removed the

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Grease Pencil: Erasing/Cutting does not auto-key layers #102623

Issues

My Proposal