Grease Pencil Apply Armature Modifier Issue #62715

New Issue

David · 2019-03-18T16:43:28+01:00

David commented

2019-03-18 16:43:28 +01:00

System Information
Operating system: macOS Mojave
Graphics card: NVIDIA GeForce GTX 675MX 1024 MB
Processor: 3.2 GHz Intel Core i5

Blender Version
Broken: (example: 2.80, 9099305771ec-x86_64, master, 2019-03-17, as found on the splash screen)

Short description of error
I've added an armature modifier to a grease pencil object.
When I try to apply the modifier the grease pencil object snaps back to its original position.

Every other modifier (lattice, hook, thickness) work perfectly fine when the modifier is applied.
It appears as though the Armature Modifier Apply option is not connecting with the Grease Pencil Data.

Here is a video demonstrating the current results:
https://www.levelpixellevel.com/greasepencilarmatureapply.html

I've attached a file with an example
grease_pencil_apply_armature.blend

Exact steps for others to reproduce the error
Make a simple grease pencil stroke.
Attach it via armature modifier to a simple armature.
Move the armature in pose mode to a new location.
Hit apply on the armature modifier.
Grease pencil object goes back to the original location.

**System Information** Operating system: macOS Mojave Graphics card: NVIDIA GeForce GTX 675MX 1024 MB Processor: 3.2 GHz Intel Core i5 **Blender Version** Broken: (example: 2.80, 9099305771ec-x86_64, master, 2019-03-17, as found on the splash screen) **Short description of error** I've added an armature modifier to a grease pencil object. When I try to apply the modifier the grease pencil object snaps back to its original position. Every other modifier (lattice, hook, thickness) work perfectly fine when the modifier is applied. It appears as though the Armature Modifier Apply option is not connecting with the Grease Pencil Data. Here is a video demonstrating the current results: https://www.levelpixellevel.com/greasepencilarmatureapply.html I've attached a file with an example [grease_pencil_apply_armature.blend](https://archive.blender.org/developer/F6844831/grease_pencil_apply_armature.blend) **Exact steps for others to reproduce the error** Make a simple grease pencil stroke. Attach it via armature modifier to a simple armature. Move the armature in pose mode to a new location. Hit apply on the armature modifier. Grease pencil object goes back to the original location.

David commented

2019-03-18 16:43:28 +01:00

Added subscriber: @LevelPixelLevel

Antonio Vazquez self-assigned this 2019-03-18 17:41:37 +01:00

Antonio Vazquez commented

2019-03-18 18:54:43 +01:00

Added subscriber: @Sergey

Antonio Vazquez commented

2019-03-18 18:54:43 +01:00

@Sergey I don't know why it's not working the armature deform here.

If you look at MOD_gpencilarmature.c in function bakeModifier() you will see the apply is using the same logic used in viewport (also other modifiers like Hook use the same logic). Ihave done a debug and the function is executed, but the deformed point is equal to original point. It looks the armature is not deformed.

Maybe there are something wrong in the loop around BKE_scene_graph_update_for_newframe() or the armatures need something else/different.

Could you help me here?

@Sergey I don't know why it's not working the armature deform here. If you look at **MOD_gpencilarmature.c** in function **bakeModifier()** you will see the apply is using the same logic used in viewport (also other modifiers like Hook use the same logic). Ihave done a debug and the function is executed, but the deformed point is equal to original point. It looks the armature is not deformed. Maybe there are something wrong in the loop around *BKE_scene_graph_update_for_newframe()* or the armatures need something else/different. Could you help me here?

Sergey Sharybin commented

2019-03-19 14:52:26 +01:00

@antoniov, dependency graph operates in an evaluated domain, with all IDs being copied and decoupled from the original ones. The bakeModifier() does proper way of updating dependency graph for the new frame, but then it attempts to use original object to deform vertices.
That could work in some cases, because generally transformation matrices are copied back to original, but you should not rely on that.
Proper solution is to do all evaluation and deformation in the evaluated domain, and them copy things back (or, at least, pass all the evaluated datablocks to deformation and pass original data to be deformed).

Anyway, code worth 1000s words: P939: Fix #62715

diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c
index 11e648e355d..39738c663e0 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c
@@ -119,8 +119,10 @@ static void bakeModifier(
         Main *bmain, Depsgraph *depsgraph,
         GpencilModifierData *md, Object *ob)
 {
-	ArmatureGpencilModifierData *mmd = (ArmatureGpencilModifierData *)md;
 	Scene *scene = DEG_get_evaluated_scene(depsgraph);
+	Object *object_eval = DEG_get_evaluated_object(depsgraph, ob);
+	ArmatureGpencilModifierData *mmd = (ArmatureGpencilModifierData *)md;
+	GpencilModifierData *md_eval = BKE_gpencil_modifiers_findByName(object_eval, md->name);
 	bGPdata *gpd = ob->data;
 	int oldframe = (int)DEG_get_ctime(depsgraph);
 
@@ -137,7 +139,7 @@ static void bakeModifier(
 
 			/* compute armature effects on this frame */
 			for (bGPDstroke *gps = gpf->strokes.first; gps; gps = gps->next) {
-				deformStroke(md, depsgraph, ob, gpl, gps);
+				deformStroke(md_eval, depsgraph, object_eval, gpl, gps);
 			}
 		}
 	}

The reason it was failing is because md points to an original armature, which doesn't have runtime data needed for deformation. That dtaa is to come from evaluated armature.

@antoniov, dependency graph operates in an evaluated domain, with all IDs being copied and decoupled from the original ones. The `bakeModifier()` does proper way of updating dependency graph for the new frame, but then it attempts to use original object to deform vertices. That could work in some cases, because generally transformation matrices are copied back to original, but you should not rely on that. Proper solution is to do all evaluation and deformation in the evaluated domain, and them copy things back (or, at least, pass all the evaluated datablocks to deformation and pass original data to be deformed). Anyway, code worth 1000s words: [P939: Fix #62715](https://archive.blender.org/developer/P939.txt) ``` diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c index 11e648e355d..39738c663e0 100644 --- a/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c +++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c @@ -119,8 +119,10 @@ static void bakeModifier( Main *bmain, Depsgraph *depsgraph, GpencilModifierData *md, Object *ob) { - ArmatureGpencilModifierData *mmd = (ArmatureGpencilModifierData *)md; Scene *scene = DEG_get_evaluated_scene(depsgraph); + Object *object_eval = DEG_get_evaluated_object(depsgraph, ob); + ArmatureGpencilModifierData *mmd = (ArmatureGpencilModifierData *)md; + GpencilModifierData *md_eval = BKE_gpencil_modifiers_findByName(object_eval, md->name); bGPdata *gpd = ob->data; int oldframe = (int)DEG_get_ctime(depsgraph); @@ -137,7 +139,7 @@ static void bakeModifier( /* compute armature effects on this frame */ for (bGPDstroke *gps = gpf->strokes.first; gps; gps = gps->next) { - deformStroke(md, depsgraph, ob, gpl, gps); + deformStroke(md_eval, depsgraph, object_eval, gpl, gps); } } } ``` The reason it was failing is because md points to an original armature, which doesn't have runtime data needed for deformation. That dtaa is to come from evaluated armature.

blender-admin commented

2019-03-19 16:03:50 +01:00

This issue was referenced by 08fe29e52f

This issue was referenced by 08fe29e52f161398682570eff45d8de391b73df8

Antonio Vazquez commented

2019-03-19 16:04:15 +01:00

Changed status from 'Open' to: 'Resolved'

Antonio Vazquez closed this issue

2019-03-19 16:04:15 +01:00

David commented

2019-03-20 00:26:54 +01:00

@antoniov and @Sergey thank you for fixing this so quickly!

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Grease Pencil Apply Armature Modifier Issue #62715