Fix T60836: Stretch to flickers when vertex group is used

Missing relation to object transform. Needed to convert vertex
position from local target object space to a local space of the
bone.

2 files changed, 13 insertions, 6 deletions

diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index a27507954fb..633646da918 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -1062,10 +1062,17 @@ void DepsgraphRelationBuilder::build_constraints(ID *id,
 				         (ct->subtarget[0]))
 				{
 					/* Vertex group. */
-					/* NOTE: for now, we don't need to represent vertex groups
-					 * separately. */
-					ComponentKey target_key(&ct->tar->id, NodeType::GEOMETRY);
-					add_relation(target_key, constraint_op_key, cti->name);
+					/* NOTE: Vertex group is likely to be used to get vertices
+					 * in a world space. This requires to know both geometry
+					 * and transformation of the target object. */
+					ComponentKey target_transform_key(
+					        &ct->tar->id, NodeType::TRANSFORM);
+					ComponentKey target_geometry_key(
+					        &ct->tar->id, NodeType::GEOMETRY);
+					add_relation(
+					        target_transform_key, constraint_op_key, cti->name);
+					add_relation(
+					        target_geometry_key, constraint_op_key, cti->name);
 					add_customdata_mask(ct->tar, CD_MASK_MDEFORMVERT);
 				}
 				else if (con->type == CONSTRAINT_TYPE_SHRINKWRAP) {
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations_rig.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations_rig.cc
index 0915da3f7cc..3ef0a13db66 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations_rig.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations_rig.cc
@@ -102,12 +102,12 @@ void DepsgraphRelationBuilder::build_ik_pose(Object *object,
 	/* IK target */
 	/* TODO(sergey): This should get handled as part of the constraint code. */
 	if (data->tar != NULL) {
-		/* TODO(sergey): For until we'll store partial matricies in the
+		/* TODO(sergey): For until we'll store partial matrices in the
 		 * depsgraph, we create dependency between target object and pose eval
 		 * component.
 		 *
 		 * This way we ensuring the whole subtree is updated from scratch
-		 * without need of intermediate matricies. This is an overkill, but good
+		 * without need of intermediate matrices. This is an overkill, but good
 		 * enough for testing IK solver. */
 		ComponentKey pose_key(&object->id, NodeType::EVAL_POSE);
 		if ((data->tar->type == OB_ARMATURE) && (data->subtarget[0])) {