This patch allows you to dynamically control stroke's opacity and thickness using an object for distance reference in the modifier. Fading range is adjustable, and it is compatible with current curve/vertex group selection.
See GIF for example:
Details
Details
- Reviewers
Antonio Vazquez (antoniov) Matias Mendiola (mendio) - Group Reviewers
Grease Pencil - Maniphest Tasks
- T80194: LineArt: New module to generate lines over meshes using grease pencil as target
T82177: Grease pencil fading settings for Thickness and Opacity - Commits
- rBf8f7c0ca6db8: GPencil: Fading based on distance to reference object in Opacity and Thickness…
Diff Detail
Diff Detail
- Repository
- rB Blender
- Branch
- temp-gpencil-fading-modifier
- Build Status
Buildable 10964 Build 10964: arc lint + arc unit
Event Timeline
| source/blender/gpencil_modifiers/intern/MOD_gpencilopacity.c | ||
|---|---|---|
| 204 | Why don't calculate only once the distance and reuse in Stroke and Fill? Also, this avoid duplicate code, no? | |
| 282 | "use_fading" better than "fading" | |
| source/blender/gpencil_modifiers/intern/MOD_gpencilthick.c | ||
| 223 | "use_fading" better than "fading" | |
| source/blender/makesrna/intern/rna_gpencil_modifier.c | ||
| 895 | "use_fading" better than "fading" | |
| 1416 | "use_fading" better than "fading" | |
Comment Actions
What is the motivation for this feature? This sounds like the kind of thing that can be done with a driver. I can imagine hundreds of properties that would be useful to modify based on an object position, it's not clear to me why this needs built-in support rather than working through the generic driver system (which can be made more user friendly).
| source/blender/gpencil_modifiers/intern/MOD_gpencilopacity.c | ||
|---|---|---|
| 150 | Don't use loc, it does not contain the final position after constraints and parenting, use the translation from the object matrix instead. | |
| source/blender/gpencil_modifiers/intern/MOD_gpencilopacity.c | ||
|---|---|---|
| 204 | For stroke is every point, for filling it's the origin to the reference object. | |
| source/blender/gpencil_modifiers/intern/MOD_gpencilopacity.c | ||
|---|---|---|
| 150 | Got it. This is for computing fading based on distance from the reference object. Maybe a driver would be good, but that would be hard to set per-stroke. Doing it this way it's more convenient. | |
Comment Actions
Updated for better handling of fading effects, can control both start and end factors.
Comment Actions
I have tested with a simple driver and the Opacity modifier and I get something similar...not with so many options, but it works.
I don't know what is the opinion of @Matias Mendiola (mendio) and @Daniel Martinez Lara (pepeland) about this.
Comment Actions
This patch takes _per-vertex_ distance rather than object origin distance, drivers can't do that. This is more versatile as this could be used on a large drawing that comes from one GPencil object.
Comment Actions
@YimingWu (NicksBest) I know, my point is to know if this feature by vertex worth a new modifier.. really I don't know, we need the opinion of artists.
Comment Actions
@Antonio Vazquez (antoniov) It's not a separate modifier, it's just improvement on the existing one. Yes we should wait for the opinions from the artists as well.
Comment Actions
I'm using the equivalent to this modifier in Freestyle (Distance to Object) a lot, and I think this is also necessary for LineArt/GP.
Comment Actions
In general, LGTM.
Not sure if you need initializate the variables or not. If you need it, there is a change how is done now. You can find examples in other modifiers.
| source/blender/gpencil_modifiers/intern/MOD_gpencilopacity.c | ||
|---|---|---|
| 98 | You could here exit before and reduce if levels if (((mmd->flag & GP_OPACITY_FADING) == 0) || ((mmd->object) == NULL)) {
return factor_depth;
} | |
Comment Actions
- Merge remote-tracking branch 'origin/master' into temp-gpencil-fading-modifier
- GPencil: simplify fading condition.
Comment Actions
I have tested and if you remove the Modifier, the reference object user count get negative. If you try to delete this empty, gets an assert.
ERROR (bke.lib_id): D:\MyBlender\BlenderDEV\blender\source\blender\blenkernel\intern\lib_id.c:292 id_us_min: ID user decrement error: OBEmpty (from '[Main]'): 0 <= 0
Comment Actions
- GPencil: Use IDWALK_CB_NOP for object references.
- GPencil: Do not hide fading options when uncheked.
Comment Actions
I have tested and now is working as expected.
I would like to have the UI review, especially, the parameter names and the tooltips, before commit the patch.
@Matias Mendiola (mendio) Any comment?
Comment Actions
@YimingWu (NicksBest) BTW, when you commit this change to master, be sure to update the Wiki page of the release notes (https://wiki.blender.org/wiki/Reference/Release_Notes/2.92/Grease_Pencil). Now, it's mandatory to include all changes in the release notes.
Comment Actions
due that this modifier feature is tight related to the new Line Art module and also that Line Art is under review and still could suffer a lot of changes, I suggest waiting for a final Line Art design before commit
Comment Actions
The new Modifier options work really nice but the Influence panel in all Grease Pencil modifiers is always the last one, please move it below the new Fading panel
