fix [#25429] Armature modifier and inverted vertex group

- the invert flag was only being used for multi-modifier, but there is no reason not to use this in normal cases as well.
- Armature modifier RNA name 'vertex_group' was incorrectly named 'vertex_group_multi_modifier' (own fault), confusion was caused by 'invert_vertex_group_multi_modifier' which was correct.

2 files changed, 7 insertions, 11 deletions

diff --git a/source/blender/blenkernel/intern/armature.c b/source/blender/blenkernel/intern/armature.c
index 22d27dc2fde..6b21e45ddd9 100644
--- a/source/blender/blenkernel/intern/armature.c
+++ b/source/blender/blenkernel/intern/armature.c
@@ -936,19 +936,15 @@ void armature_deform_verts(Object *armOb, Object *target, DerivedMesh *dm,
 			dvert = NULL;
 
 		if(armature_def_nr >= 0 && dvert) {
-			armature_weight = 0.0f; /* a def group was given, so default to 0 */
-			for(j = 0; j < dvert->totweight; j++) {
-				if(dvert->dw[j].def_nr == armature_def_nr) {
-					armature_weight = dvert->dw[j].weight;
-					break;
-				}
+			armature_weight= defvert_find_weight(dvert, armature_def_nr);
+
+			if(invert_vgroup) {
+				armature_weight= 1.0f-armature_weight;
 			}
+
 			/* hackish: the blending factor can be used for blending with prevCos too */
 			if(prevCos) {
-				if(invert_vgroup)
-					prevco_weight= 1.0f-armature_weight;
-				else
-					prevco_weight= armature_weight;
+				prevco_weight= armature_weight;
 				armature_weight= 1.0f;
 			}
 		}
diff --git a/source/blender/blenkernel/intern/deform.c b/source/blender/blenkernel/intern/deform.c
index ad797736a85..937681fcdc3 100644
--- a/source/blender/blenkernel/intern/deform.c
+++ b/source/blender/blenkernel/intern/deform.c
@@ -448,7 +448,7 @@ void flip_side_name (char *name, const char *from_name, int strip_number)
 	sprintf (name, "%s%s%s%s", prefix, replace, suffix, number);
 }
 
-float defvert_find_weight(const struct MDeformVert *dvert, int group_num)
+float defvert_find_weight(const struct MDeformVert *dvert, const int group_num)
 {
 	MDeformWeight *dw= defvert_find_index(dvert, group_num);
 	return dw ? dw->weight : 0.0f;