Fix T73254: Drivers with the object.dimension variable are not updated

This fixes an issue where drivers using `object.dimension` only add a dependency on `GEOMETRY` to the depsgraph, whereas they should also depend on `TRANSFORM`.

This patch adds a new no-op operation that depends on the geometry and transform components to the Parameters component.

An alternative implementation would be to have `RNANodeQuery::construct_node_identifier` return multiple node identifiers. However, this would spread throughout the depsgraph code and unnecessarily force many other functions to either return or handle multiple nodes where in 99.999% of the time a single node would suffice.

The new `DIMENSIONS` node is added for each object. An upcoming patch will go over all no-op operation nodes and remove them from the depsgraph. Since this is a more dangerous operation, it'll be reviewed separately.

Differential Revision: https://developer.blender.org/D7031

source/blender/depsgraph/intern/builder/deg_builder_nodes.cc

@@ -991,6 +991,12 @@ void DepsgraphNodeBuilder::build_parameters(ID *id)
   op_node->set_as_exit();
 }
 
+void DepsgraphNodeBuilder::build_dimensions(Object *object)
+{
+  /* Object dimensions (bounding box) node. Will depend on both geometry and transform. */
+  add_operation_node(&object->id, NodeType::PARAMETERS, OperationCode::DIMENSIONS);
+}
+
 /* Recursively build graph for world */
 void DepsgraphNodeBuilder::build_world(World *world)
 {
@@ -1224,6 +1230,7 @@ void DepsgraphNodeBuilder::build_object_data_geometry(Object *object, bool is_ob
   build_object_pointcache(object);
   /* Geometry. */
   build_object_data_geometry_datablock((ID *)object->data, is_object_visible);
+  build_dimensions(object);
   /* Batch cache. */
   add_operation_node(&object->id,
                      NodeType::BATCH_CACHE,

source/blender/depsgraph/intern/builder/deg_builder_nodes.h

@@ -192,6 +192,7 @@ class DepsgraphNodeBuilder : public DepsgraphBuilder {
   virtual void build_driver_variables(ID *id, FCurve *fcurve);
   virtual void build_driver_id_property(ID *id, const char *rna_path);
   virtual void build_parameters(ID *id);
+  virtual void build_dimensions(Object *object);
   virtual void build_ik_pose(Object *object, bPoseChannel *pchan, bConstraint *con);
   virtual void build_splineik_pose(Object *object, bPoseChannel *pchan, bConstraint *con);
   virtual void build_rig(Object *object, bool is_object_visible);

source/blender/depsgraph/intern/builder/deg_builder_relations.cc

@@ -1588,6 +1588,15 @@ void DepsgraphRelationBuilder::build_parameters(ID *id)
   add_relation(parameters_eval_key, parameters_exit_key, "Entry -> Exit");
 }
 
+void DepsgraphRelationBuilder::build_dimensions(Object *object)
+{
+  OperationKey dimensions_key(&object->id, NodeType::PARAMETERS, OperationCode::DIMENSIONS);
+  ComponentKey geometry_key(&object->id, NodeType::GEOMETRY);
+  ComponentKey transform_key(&object->id, NodeType::TRANSFORM);
+  add_relation(geometry_key, dimensions_key, "Geometry -> Dimensions");
+  add_relation(transform_key, dimensions_key, "Transform -> Dimensions");
+}
+
 void DepsgraphRelationBuilder::build_world(World *world)
 {
   if (built_map_.checkIsBuiltAndTag(world)) {
@@ -2029,6 +2038,7 @@ void DepsgraphRelationBuilder::build_object_data_geometry(Object *object)
       }
     }
   }
+  build_dimensions(object);
   /* Synchronization back to original object. */
   ComponentKey final_geometry_key(&object->id, NodeType::GEOMETRY);
   OperationKey synchronize_key(

source/blender/depsgraph/intern/builder/deg_builder_relations.h

@@ -242,6 +242,7 @@ class DepsgraphRelationBuilder : public DepsgraphBuilder {
   virtual void build_driver_variables(ID *id, FCurve *fcurve);
   virtual void build_driver_id_property(ID *id, const char *rna_path);
   virtual void build_parameters(ID *id);
+  virtual void build_dimensions(Object *object);
   virtual void build_world(World *world);
   virtual void build_rigidbody(Scene *scene);
   virtual void build_particle_systems(Object *object);

source/blender/depsgraph/intern/builder/deg_builder_rna.cc

@@ -318,7 +318,8 @@ RNANodeIdentifier RNANodeQuery::construct_node_identifier(const PointerRNA *ptr,
         return node_identifier;
       }
       else if (STREQ(prop_identifier, "dimensions")) {
-        node_identifier.type = NodeType::GEOMETRY;
+        node_identifier.type = NodeType::PARAMETERS;
+        node_identifier.operation_code = OperationCode::DIMENSIONS;
         return node_identifier;
       }
     }

source/blender/depsgraph/intern/node/deg_node_operation.cc

@@ -64,6 +64,8 @@ const char *operationCodeAsString(OperationCode opcode)
     /* Object related. */
     case OperationCode::OBJECT_BASE_FLAGS:
       return "OBJECT_BASE_FLAGS";
+    case OperationCode::DIMENSIONS:
+      return "DIMENSIONS";
     /* Transform. */
     case OperationCode::TRANSFORM_INIT:
       return "TRANSFORM_INIT";

source/blender/depsgraph/intern/node/deg_node_operation.h

@@ -63,6 +63,7 @@ enum class OperationCode {
 
   /* Object related. ------------------------------------------------------ */
   OBJECT_BASE_FLAGS,
+  DIMENSIONS,
 
   /* Transform. ----------------------------------------------------------- */
   /* Transform entry point. */