Fix T96180: driver in node tree not updating in real time

Differential Revision: https://developer.blender.org/D14260

1 files changed, 8 insertions, 0 deletions

diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index d63d1bafb3e..3b2e0f92700 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -1646,6 +1646,14 @@ void DepsgraphRelationBuilder::build_driver_data(ID *id, FCurve *fcu)
       add_relation(property_exit_key, parameters_key, "Driven Property -> Properties");
     }
   }
+
+  /* Assume drivers on a node tree affect the evaluated output of the node tree. In theory we could
+   * check if the driven value actually affects the output, i.e. if it drives a node that is linked
+   * to the output. */
+  if (GS(id_ptr->name) == ID_NT) {
+    ComponentKey ntree_output_key(id_ptr, NodeType::NTREE_OUTPUT);
+    add_relation(driver_key, ntree_output_key, "Drivers -> NTree Output");
+  }
 }
 
 void DepsgraphRelationBuilder::build_driver_variables(ID *id, FCurve *fcu)