GPv3: Fill tool #120693

Lukas Tönne · 2024-04-16T12:04:54+02:00

Lukas Tönne commented

2024-04-16 12:04:54 +02:00

Implementation of the GPv2 Fill tool in Grease Pencil 3.

UI

Show relevant brush/tool settings in the View3D header that affect the outline stroke (radius, vertex color, etc.)

Algorithm

Support inversion (does this use the outer border?)
Construct strokes from filled area outline
Reproject using depth buffer (DrawingPlacement)

Features to add later (not in this PR)

"Precision" (pixel size) setting to change render resolution
Apply correct view plane transform to match visible bounds
TBD: reimplement or discard old approach of trying different view transforms (falls back to identity transform in 2nd pass)
Implement dot/square material rendering (ed::greasepencil::image_render::draw_dots)
Extension lines for closing gaps
End point circles for closing gaps
Special boundary strokes for closing gaps
Dilate/Erode after floodfill
Smooth & Simplify after boundary construction
Better leak detection filter? Cross-shaped filter function tends to leave undesirable gaps between strokes and the filled area.

Implementation of the GPv2 Fill tool in Grease Pencil 3. ### UI - [x] Show relevant brush/tool settings in the View3D header that affect the outline stroke (radius, vertex color, etc.) ### Algorithm - [x] Support inversion (does this use the outer border?) - [x] Construct strokes from filled area outline - [x] Reproject using depth buffer (`DrawingPlacement`) ## Features to add later (not in this PR) - "Precision" (pixel size) setting to change render resolution - Apply correct view plane transform to match visible bounds - TBD: reimplement or discard old approach of trying different view transforms (falls back to identity transform in 2nd pass) - Implement dot/square material rendering (`ed::greasepencil::image_render::draw_dots`) - Extension lines for closing gaps - End point circles for closing gaps - Special boundary strokes for closing gaps - Dilate/Erode after floodfill - Smooth & Simplify after boundary construction - Better leak detection filter? Cross-shaped filter function tends to leave undesirable gaps between strokes and the filled area.

Lukas Tönne added 23 commits 2024-04-16 12:05:07 +02:00

b162f755dc Stub operator for the fill tool.

292bcf31ca Keymap entries for the fill tool and the brush stroke fallback.

5e719b6432 Merge branch 'main' into gp3-fill-tool

f70e59ea9b General enter/exit function for managing state and customdata.

c338c717d7 Merge branch 'main' into gp3-fill-tool

b441fe8234 Handle more modal stuff.

bd80f53b3a progress

5009528d1e Merge branch 'main' into gp3-fill-tool

3d2af0d3f8 Basic steps to render into an offscreen buffer.

c8fd57dce3 Merge branch 'main' into gp3-fill-tool

90008b4edb progress

2edac124eb Merge branch 'main' into gp3-fill-tool

248d3e7e5f Stroke drawing functions.

c43779b428 Fix for the boundary layer mask and bounds calculation.

388f7f5af9 progress

c1c3f00117 Merge branch 'main' into gp3-fill-tool

574c85f14b Fixed wrong alpha threshold.

0aac88e12c Draw mouse dot in correct location.

bf6913e99b Progress.

0b11212779 Flood fill algorithm for the fill tool with boundary strokes.

4567e446d2 progress

5582ba97f5 Merge branch 'main' into gp3-fill-tool

77dd43c3e0 Implemented the "leak detection" filter from GPv2.

Room for improvement here, but this is the current method.

Lukas Tönne added this to the Grease Pencil project 2024-04-16 12:05:13 +02:00

Lukas Tönne referenced this pull request

2024-04-16 12:07:04 +02:00

GPv3: Port Bucket Fill operator #114069

Lukas Tönne added 1 commit 2024-04-16 17:18:01 +02:00

641c4ebabe progress on boundary search.

Lukas Tönne added 1 commit 2024-04-16 21:02:42 +02:00

07a90c5616 Generate curves geometry.

Lukas Tönne added 1 commit 2024-04-17 10:02:03 +02:00

efc6a9cde0 Generate curves output from boundary path.

Lukas Tönne added 1 commit 2024-04-17 10:33:37 +02:00

996d7a4c54 use `tag_topology_changed` to ensure general update after join_geometries.

Lukas Tönne added 1 commit 2024-04-17 11:21:15 +02:00

5e0ddc5a24 Use same curves index mask for bounds calculation as for drawing.

Lukas Tönne added 1 commit 2024-04-17 12:20:13 +02:00

ee6a548e8a Better API separation between operator-specific code and generic fill.

Lukas Tönne added 1 commit 2024-04-17 12:32:19 +02:00

36c00f95b7 Remove context from API for fill functions.

Lukas Tönne added 1 commit 2024-04-17 12:53:51 +02:00

aad574c9c7 API documentation.

Lukas Tönne added 1 commit 2024-04-17 14:36:30 +02:00

ff85a9bc76 Removed reports list parameter.

Lukas Tönne added 1 commit 2024-04-17 15:18:19 +02:00

57fbf76935 Handle invert flag.

Lukas Tönne added 1 commit 2024-04-17 15:26:48 +02:00

186a03515e Removed unused stroke construction code.

Lukas Tönne added 1 commit 2024-04-17 16:14:55 +02:00

43bba95093 Added a border mode to control if filling to the border is allowed.

Lukas Tönne added 1 commit 2024-04-17 16:34:12 +02:00

8181b42d1f Accept border pixels when inverting the image.

Lukas Tönne added 1 commit 2024-04-18 09:32:57 +02:00

00fbf68287 Attempt to store more flags per color.

Lukas Tönne added 1 commit 2024-04-18 10:19:01 +02:00

7c8fa7c317 Merge branch 'main' into gp3-fill-tool

Lukas Tönne added 1 commit 2024-04-18 11:49:45 +02:00

c6f7f7315c Treat image as a byte buffer for more flag access.

Lukas Tönne added 1 commit 2024-04-18 16:24:05 +02:00

1ac103d2b2 progress

Lukas Tönne added 1 commit 2024-04-19 13:28:00 +02:00

45b165e8e0 Implementation of the invert feature that generates exterior boundaries.

Lukas Tönne added 1 commit 2024-04-19 14:33:56 +02:00

3c29bb93a2 Cleanup: removed unused code.

Sietse Brouwer commented

2024-04-22 00:20:43 +02:00

As a clarification of the gap closure methods – there are three ways:

Extend mode: extrapolating the outer segments of strokes.
Radius mode: connecting the outer points of strokes.
Boundary ('helper') lines, drawn with Alt-LMB.

As a clarification of the gap closure methods – there are three ways: 1. Extend mode: extrapolating the outer segments of strokes. 2. Radius mode: connecting the outer points of strokes. 3. Boundary ('helper') lines, drawn with `Alt-LMB`. ![GPv3 Fill tool gap closure methods.jpg](/attachments/e513922b-0168-475e-8db1-842968174e3c)

GPv3 Fill tool gap closure methods.jpg

134 KiB

Sietse Brouwer reviewed 2024-04-22 00:38:08 +02:00

Sietse Brouwer left a comment

I know it's just WIP yet, but I wanted to mention that multi frame editing complicates things a bit.

In the example above, with multi frame editing enabled, the fill tool should be executed three times: for frame 1, 5 and 10. So the drawings should be retrieved grouped per frame number.

I mention it now, because it might influence how you organize your data. The boundary layers, for example, can differ per group. And the collisions of extend lines also need to be calculated per group.

I know it's just WIP yet, but I wanted to mention that multi frame editing complicates things a bit. ![GPv3 Fill tool with multi frame editing.png](/attachments/6ebe7dde-dd93-4554-b87e-9defea4c24d1) In the example above, with multi frame editing enabled, the fill tool should be executed three times: for frame 1, 5 and 10. So the drawings should be retrieved grouped per frame number. I mention it now, because it might influence how you organize your data. The boundary layers, for example, can differ per group. And the collisions of extend lines also need to be calculated per group.

GPv3 Fill tool with multi frame editing.png

18 KiB

source/blender/editors/sculpt_paint/grease_pencil_draw_ops.cc Outdated

						
				@ -439,0 +640,4 @@

				  /* Drawings that form boundaries for the generated strokes. */

				  const Vector<DrawingInfo> src_drawings = ed::greasepencil::retrieve_visible_drawings(

				      scene, grease_pencil, false);

Sietse Brouwer commented

2024-04-22 00:24:21 +02:00

To handle multi frame editing, the drawings must be retrieved grouped by frame number.

To handle multi frame editing, the drawings must be retrieved _grouped by frame number_.

Lukas Tönne commented

2024-05-02 17:44:29 +02:00

I don't think there is a good utility function for this specific case yet (and it's so special that i don't think adding one is justified). I'll do this locally for the operator:

For each frame in the multi-frame-edit range:
   Get the editable drawing (if any) in the _active layer_ (this is where the new strokes go)
   Get all visible drawings, from any layer (these form the fill borders)

retrieve_editable_drawings_grouped_per_frame is close, but i only want the drawing from the active layer, otherwise the same boundary strokes would get added to all the layers.
retrieve_visible_drawings does not group drawings by frame which is probably desirable, otherwise the result would again be the same in every frame.

I don't think there is a good utility function for this specific case yet (and it's so special that i don't think adding one is justified). I'll do this locally for the operator: ``` For each frame in the multi-frame-edit range: Get the editable drawing (if any) in the _active layer_ (this is where the new strokes go) Get all visible drawings, from any layer (these form the fill borders) ``` `retrieve_editable_drawings_grouped_per_frame` is close, but i only want the drawing from the active layer, otherwise the same boundary strokes would get added to all the layers. `retrieve_visible_drawings` does not group drawings by frame which is probably desirable, otherwise the result would again be the same in every frame.

👍 1

LukasTonne marked this conversation as resolved

Lukas Tönne added 1 commit 2024-04-22 09:34:28 +02:00

52fb2bff7b Merge branch 'main' into gp3-fill-tool

Lukas Tönne commented

2024-04-22 09:39:43 +02:00

Thank you @SietseB for the explanation!

I'll try to structure the code in such a way that the different stages of the tool are more clearly separated. The GPv2 tool is using the same tGPDfill struct for every single function, which makes it hard to tell which data is relevant for which part of the process.

Find all the target drawings (including multi-frame edits)
Find relevant source drawings for each target, i.e. the drawings with regular boundary strokes.
Render source strokes together with extension lines into the boundary buffer.
Flood fill the seeded area, or all non-seeded areas if inverted.
Find outlines and convert them to strokes.
Post-processing for simplification/smoothing/etc.
Join new strokes with existing geometry.

Thank you @SietseB for the explanation! I'll try to structure the code in such a way that the different stages of the tool are more clearly separated. The GPv2 tool is using the same `tGPDfill` struct for every single function, which makes it hard to tell which data is relevant for which part of the process. 1. Find all the _target_ drawings (including multi-frame edits) 2. Find relevant _source_ drawings for each target, i.e. the drawings with regular boundary strokes. 3. Render source strokes together with extension lines into the boundary buffer. 4. Flood fill the seeded area, or all non-seeded areas if inverted. 5. Find outlines and convert them to strokes. 6. Post-processing for simplification/smoothing/etc. 7. Join new strokes with existing geometry.

👍 1

Lukas Tönne added 1 commit 2024-04-22 10:52:14 +02:00

a5f7642f47 Revert FILL_DEBUG change in legacy gpencil code.

Lukas Tönne added 1 commit 2024-04-22 12:14:56 +02:00

66f073cbc5 Fix boundary concatenation and crashes from immediate mode drawing outside of main thread.

Lukas Tönne added 1 commit 2024-04-22 15:39:14 +02:00

9f70ab657a Fixed concatenation of boundary sections.

Lukas Tönne added 2 commits 2024-04-22 17:09:12 +02:00

6c261a69e9 Can use a single map for initial points and finished sections.

5cb82e7c92 Fix duplicate outlines due to points getting moved before checking for empty sections.

Lukas Tönne added 1 commit 2024-04-22 17:13:48 +02:00

69eb002a73 Revert debugging changes for smaller window size.