Geometry Nodes: Add default attribute name to field inputs/outputs

Geometry node group inputs and outputs get a new property that controls
the attribute name used for that field input/output when assigning the
node group to a modifier for the first time. If the default name is assigned
to an input, the default "Use attribute name" is true .

In order to properly detect when a node group is first assigned,
the modifier now clears its properties when clearing the node group.

Ref T96707

Differential Revision: https://developer.blender.org/D14761

1 files changed, 8 insertions, 0 deletions

diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index 1b9192c75cf..d18fe1b81dd 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -139,6 +139,14 @@ typedef struct bNodeSocket {
   char label[64];
   char description[64];
 
+  /**
+   * The default attribute name to use for geometry nodes modifier output attribute sockets.
+   * \note Storing this pointer in every single socket exposes the bad design of using sockets
+   * to describe group inputs and outputs. In the future, it should be stored in socket
+   * declarations.
+   */
+  char *default_attribute_name;
+
   /** Cached data from execution. */
   void *cache;