Grease Pencil: New lines in Multiframe editing appear as Onion skinning overlay #101548

New Issue

System Information
Operating system: Windows-10-10.0.19043-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 516.59

Blender Version
Broken: version: 3.4.0 Alpha, branch: master, commit date: 2022-09-30 22:40, hash: 206dead860
Worked: (newest version of Blender that worked as expected)

Short description of error
When using Multiframe editing and drawing new lines in Draw Mode, the new lines will falsely be drawn with onion skinning colors.
The new line will have been drawn on all frames, so it should be drawn as its own color when switching to other frames.

gp_bug2.mp4

Exact steps for others to reproduce the error

Add a grease pencil object
Draw a new line on a bunch of different frames
Enable the onion skinning overlay
Enable multiframe editing and make sure all keyframes are selected
Draw a new line and move the current frame

**System Information** Operating system: Windows-10-10.0.19043-SP0 64 Bits Graphics card: NVIDIA GeForce GTX 1060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 516.59 **Blender Version** Broken: version: 3.4.0 Alpha, branch: master, commit date: 2022-09-30 22:40, hash: `206dead860` Worked: (newest version of Blender that worked as expected) **Short description of error** When using Multiframe editing and drawing new lines in Draw Mode, the new lines will falsely be drawn with onion skinning colors. The new line will have been drawn on all frames, so it should be drawn as its own color when switching to other frames. [gp_bug2.mp4](https://archive.blender.org/developer/F13605948/gp_bug2.mp4) **Exact steps for others to reproduce the error** - Add a grease pencil object - Draw a new line on a bunch of different frames - Enable the onion skinning overlay - Enable multiframe editing and make sure all keyframes are selected - Draw a new line and move the current frame

Added subscriber: @JulienKaspar

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

Added subscriber: @PratikPB2123

Added subscriber: @antoniov

Can reproduce. The problem looks related to the copy to eval data. The stroke is created but not copied to eval data, so it's consider that the stroke is not in the frame, but really it is.

Maybe, this is related to the last optimization for copying only part of the eval data.

To reproduce:

Open file and draw a line. If you save and reopen works.

SimpleMultiframe.blend

Can reproduce. The problem looks related to the copy to eval data. The stroke is created but not copied to eval data, so it's consider that the stroke is not in the frame, but really it is. Maybe, this is related to the last optimization for copying only part of the eval data. To reproduce: Open file and draw a line. If you save and reopen works. [SimpleMultiframe.blend](https://archive.blender.org/developer/F13609145/SimpleMultiframe.blend)

Added subscriber: @filedescriptor

@filedescriptor Could you take a look of this? I guess the error is located in these lines of gpencil_paint.c:

/* In multi-frame mode, duplicate the stroke in other frames. */
  if (GPENCIL_MULTIEDIT_SESSIONS_ON(p->gpd)) {
    const bool tail = (ts->gpencil_flags & GP_TOOL_FLAG_PAINT_ONBACK);
    BKE_gpencil_stroke_copy_to_keyframes(gpd, gpl, p->gpf, gps, tail);
  }

  gpencil_update_cache(p->gpd);
  BKE_gpencil_tag_full_update(p->gpd, gpl, p->gpf, NULL);

My guess is the function only updates the current gps, but not the strokes created by BKE_gpencil_stroke_copy_to_keyframes

Edit: The problem is the copy is only for the frame, my suggested change is call BKE_gpencil_tag_full_update passing frame as NULL if there is multiframe draw.

@filedescriptor Could you take a look of this? I guess the error is located in these lines of `gpencil_paint.c`: ``` /* In multi-frame mode, duplicate the stroke in other frames. */ if (GPENCIL_MULTIEDIT_SESSIONS_ON(p->gpd)) { const bool tail = (ts->gpencil_flags & GP_TOOL_FLAG_PAINT_ONBACK); BKE_gpencil_stroke_copy_to_keyframes(gpd, gpl, p->gpf, gps, tail); } gpencil_update_cache(p->gpd); BKE_gpencil_tag_full_update(p->gpd, gpl, p->gpf, NULL); ``` My guess is the function only updates the current `gps`, but not the strokes created by `BKE_gpencil_stroke_copy_to_keyframes` Edit: The problem is the copy is only for the frame, my suggested change is call `BKE_gpencil_tag_full_update` passing frame as NULL if there is multiframe draw.

This issue was referenced by 1bdb5542ff

This issue was referenced by 1bdb5542ff0d13a26fb9f94988cedd679a3172b7

This issue was referenced by 035c237d69

This issue was referenced by 035c237d69d196048cc2b56274aa98b04256f46c

Changed status from 'Confirmed' to: 'Resolved'

@antoniov We could also tag frames in BKE_gpencil_stroke_copy_to_keyframes knowing that just tagging the layer can be slower.

@antoniov We could also tag frames in `BKE_gpencil_stroke_copy_to_keyframes` knowing that just tagging the layer can be slower.

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Grease Pencil: New lines in Multiframe editing appear as Onion skinning overlay #101548