GPv3: Join Strokes #113570

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Pratik Borhade · 2023-10-12T07:45:11+02:00

Pratik Borhade commented

2023-10-12 07:45:11 +02:00

Join selected strokes

Define GREASE_PENCIL_OT_stroke_join operator in grease_pencil_edit.cc
For first selected stroke: create pointers to reference first_curve_index and layer-drawing.
Iterate through all the drawings at current scene frame (retrieve_editable_drawings)
- Get geometry of this drawing: bke::CurvesGeometry &curves = drawing.strokes_for_write();
- Check whether point/stroke is selected and identify index of selected curve
- If pointers of first selected stroke are null, reference them.
- Else: include these stroke-points at the end of first_selected_curve
  - Get geometry where first selected curve belongs: curves = drawing.strokes_for_write();
  - resize geometry of first selected curve: curves.resize()
  - Update the offset value of first selected curve (eventually need to update offset value of complete geometry)
  - Update position attribute

For reference:
see legacy GP operator: GPENCIL_OT_stroke_join
Also see other grease_pencil_* files

Join selected strokes - Define `GREASE_PENCIL_OT_stroke_join` operator in `grease_pencil_edit.cc` - For first selected stroke: create pointers to reference `first_curve_index` and layer-drawing. - Iterate through all the drawings at current scene frame (`retrieve_editable_drawings`) - Get geometry of this drawing: `bke::CurvesGeometry &curves = drawing.strokes_for_write();` - Check whether point/stroke is selected and identify index of selected curve - If pointers of first selected stroke are null, reference them. - Else: include these stroke-points at the end of first_selected_curve - Get geometry where first selected curve belongs: `curves = drawing.strokes_for_write();` - resize geometry of first selected curve: `curves.resize()` - Update the offset value of first selected curve (eventually need to update offset value of complete geometry) - Update position attribute For reference: see legacy GP operator: `GPENCIL_OT_stroke_join` Also see other `grease_pencil_*` files

Pratik Borhade added the

labels 2023-10-12 07:45:12 +02:00

Pratik Borhade added this to the Grease Pencil project 2023-10-12 12:08:36 +02:00

Pratik Borhade added

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labels 2023-10-12 12:49:49 +02:00

Pratik Borhade added the

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Grease Pencil

label 2023-10-12 13:30:58 +02:00

Falk David referenced this issue

2023-10-25 18:43:46 +02:00

GPv3: Community Tasks: Overview #114158

Nicolas-Mayora referenced this issue

2023-12-06 21:18:11 +01:00

GPv3: Community Tasks: Overview #114158

Falk David commented

2023-12-07 10:46:43 +01:00

@Nicolas-Mayora is giving this a shot.

Nicolas-Mayora commented

2023-12-07 16:56:17 +01:00

After a quick discussion on the #grease-pencil-module channel, @filedescriptor came up with the following (high-level-ish) implementation:

Find all selected strokes and extract their end-points. (1)
Add them all to a KDTree_3d using BLI_kdtree_3d_insert.
For each point obtained in (1), let it be x:
- Use BLI_kdtree_3d_find_nearest_n to get x's two nearest neighbours.
  - We need to get the two closest in case the closest is from x's own stroke, in which case, we discard it.
- Create an edge between x with its closest (valid) neighbour.
- Remove x and it's new neighbour from the KDTree.

After a quick discussion on the #grease-pencil-module channel, @filedescriptor came up with the following (high-level-ish) implementation: - Find all selected strokes and extract their end-points. (1) - Add them all to a `KDTree_3d` using `BLI_kdtree_3d_insert`. - For each point obtained in (1), let it be `x`: - Use `BLI_kdtree_3d_find_nearest_n` to get `x`'s two nearest neighbours. - We need to get the _two_ closest in case _the_ closest is from `x`'s own stroke, in which case, we discard it. - Create an edge between `x` with its closest (valid) neighbour. - Remove `x` and it's new neighbour from the KDTree.

YimingWu commented

2023-12-25 09:34:55 +01:00

@Nicolas-Mayora there's another thing that's potentially important that is we need to consider the direction of how we join strokes, so that we can avoid zig-zagging in the result, which is also sometimes a nasty problem in line art chaining algorithm.

line art does have the 2d tile-based acceleration method. Maybe that can be used.

@Nicolas-Mayora there's another thing that's potentially important that is we need to consider the direction of how we join strokes, so that we can avoid zig-zagging in the result, which is also sometimes a nasty problem in line art chaining algorithm. line art does have the 2d tile-based acceleration method. Maybe that can be used.

Matias Mendiola referenced this issue

2024-01-17 22:17:42 +01:00

GPv3: Merge Points #116726

Falk David commented

2024-01-23 11:20:22 +01:00

The "Join Strokes" operator seems to duplicate logic in the "Merge Points" operator. So the #116726: GPv3: Merge Points PR will replace this one.

The "Join Strokes" operator seems to duplicate logic in the "Merge Points" operator. So the [#116726: GPv3: Merge Points](https://projects.blender.org/blender/blender/pulls/116726) PR will replace this one.

Falk David closed this issue

2024-01-23 11:20:25 +01:00

Blender Bot added the

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Archived

label 2024-01-23 11:20:26 +01:00

~~Pedro referenced this issue 2024-01-28 21:35:46 +01:00~~

GPv3: Merge Points #116726

Pedro referenced this issue

2024-01-28 21:48:15 +01:00

GPv3: Merge Points #116726

Pedro referenced this issue