- particle drawing was using invalid memory with weights.

- particle set weight operator (Shift + K) and from the menu.
- mirror vertex groups operator can also flip weight group names.

a number of utility functions for weight groups added
 int *get_defgroup_flip_map(struct Object *ob);
 void flip_vertexgroup_name (char *name_r, const char *name, int strip_number); // moved from modifier.c 
 void copy_defvert (struct MDeformVert *dvert_r, const struct MDeformVert *dvert);
 void flip_defvert (struct MDeformVert *dvert, int *flip_map);

3 files changed, 50 insertions, 0 deletions

diff --git a/source/blender/editors/physics/particle_edit.c b/source/blender/editors/physics/particle_edit.c
index fe38d71dc92..f0870ca9764 100644
--- a/source/blender/editors/physics/particle_edit.c
+++ b/source/blender/editors/physics/particle_edit.c
@@ -2366,6 +2366,52 @@ void PARTICLE_OT_remove_doubles(wmOperatorType *ot)
 	RNA_def_float(ot->srna, "threshold", 0.0002f, 0.0f, FLT_MAX, "Threshold", "Threshold distance withing which particles are removed", 0.00001f, 0.1f);
 }
 
+
+static int weight_set_exec(bContext *C, wmOperator *op)
+{
+	Scene *scene= CTX_data_scene(C);
+	ParticleEditSettings *pset= PE_settings(scene);
+	Object *ob= CTX_data_active_object(C);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
+	ParticleSystem *psys = edit->psys;
+	POINT_P;
+	KEY_K;
+	HairKey *hkey;
+	float weight;
+	ParticleBrushData *brush= &pset->brush[pset->brushtype];
+	edit= psys->edit;
+
+	weight= (float)(brush->strength / 100.0f);
+
+	LOOP_SELECTED_POINTS {
+		ParticleData *pa= psys->particles + p;
+
+		LOOP_SELECTED_KEYS {
+			hkey= pa->hair + k;
+			hkey->weight= weight;
+		}
+	}
+
+	DAG_id_flush_update(&ob->id, OB_RECALC_DATA);
+	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE_DATA, ob);
+
+	return OPERATOR_FINISHED;
+}
+
+void PARTICLE_OT_weight_set(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "Weight Set";
+	ot->idname= "PARTICLE_OT_weight_set";
+
+	/* api callbacks */
+	ot->exec= weight_set_exec;
+	ot->poll= PE_poll;
+
+	/* flags */
+	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
+}
+
 /************************ cursor drawing *******************************/
 
 static void brush_drawcursor(bContext *C, int x, int y, void *customdata)
diff --git a/source/blender/editors/physics/physics_intern.h b/source/blender/editors/physics/physics_intern.h
index cc0a288f8be..3de5c256df7 100644
--- a/source/blender/editors/physics/physics_intern.h
+++ b/source/blender/editors/physics/physics_intern.h
@@ -50,6 +50,7 @@ void PARTICLE_OT_reveal(struct wmOperatorType *ot);
 void PARTICLE_OT_rekey(struct wmOperatorType *ot);
 void PARTICLE_OT_subdivide(struct wmOperatorType *ot);
 void PARTICLE_OT_remove_doubles(struct wmOperatorType *ot);
+void PARTICLE_OT_weight_set(struct wmOperatorType *ot);
 void PARTICLE_OT_delete(struct wmOperatorType *ot);
 void PARTICLE_OT_mirror(struct wmOperatorType *ot);
 
diff --git a/source/blender/editors/physics/physics_ops.c b/source/blender/editors/physics/physics_ops.c
index 5cb8230e463..2728f64a777 100644
--- a/source/blender/editors/physics/physics_ops.c
+++ b/source/blender/editors/physics/physics_ops.c
@@ -57,6 +57,7 @@ static void operatortypes_particle(void)
 	WM_operatortype_append(PARTICLE_OT_rekey);
 	WM_operatortype_append(PARTICLE_OT_subdivide);
 	WM_operatortype_append(PARTICLE_OT_remove_doubles);
+	WM_operatortype_append(PARTICLE_OT_weight_set);	
 	WM_operatortype_append(PARTICLE_OT_delete);
 	WM_operatortype_append(PARTICLE_OT_mirror);
 
@@ -111,6 +112,8 @@ static void keymap_particle(wmKeyConfig *keyconf)
 	RNA_enum_set(WM_keymap_add_item(keymap, "PARTICLE_OT_brush_radial_control", FKEY, KM_PRESS, KM_SHIFT, 0)->ptr, "mode", WM_RADIALCONTROL_STRENGTH);
 
 	WM_keymap_add_menu(keymap, "VIEW3D_MT_particle_specials", WKEY, KM_PRESS, 0, 0);
+	
+	WM_keymap_add_item(keymap, "PARTICLE_OT_weight_set", KKEY, KM_PRESS, KM_SHIFT, 0);
 
 	ED_object_generic_keymap(keyconf, keymap, 1);
 }