Geometry Nodes: Add named attribute nodes behind experimental flag

This commit adds three nodes:
- `Remove Attribute`: Removes an attribute with the given name
- `Named Attribute`: A field input node
- `Store Named Attribute`: Puts results of a field in a named attribute

They are added behind a new experimental feature flag, because further
development of attribute search and name dependency visualization will
happen as separate steps.

Ref T91742

Differential Revision: https://developer.blender.org/D12685

2 files changed, 9 insertions, 0 deletions

diff --git a/release/scripts/startup/bl_ui/space_userpref.py b/release/scripts/startup/bl_ui/space_userpref.py
index f80ad378b3c..09716c77917 100644
--- a/release/scripts/startup/bl_ui/space_userpref.py
+++ b/release/scripts/startup/bl_ui/space_userpref.py
@@ -2262,6 +2262,7 @@ class USERPREF_PT_experimental_new_features(ExperimentalPanel, Panel):
                 ({"property": "use_sculpt_tools_tilt"}, "T82877"),
                 ({"property": "use_extended_asset_browser"}, ("project/view/130/", "Project Page")),
                 ({"property": "use_override_templates"}, ("T73318", "Milestone 4")),
+                ({"property": "use_named_attribute_nodes"}, ("T91742")),
             ),
         )
 
diff --git a/release/scripts/startup/nodeitems_builtins.py b/release/scripts/startup/nodeitems_builtins.py
index a0205a2bcb1..705b98c4d11 100644
--- a/release/scripts/startup/nodeitems_builtins.py
+++ b/release/scripts/startup/nodeitems_builtins.py
@@ -201,6 +201,8 @@ def geometry_input_node_items(context):
     yield NodeItem("ShaderNodeValue")
     yield NodeItem("FunctionNodeInputVector")
     yield NodeItemCustom(draw=lambda self, layout, context: layout.separator())
+    if named_attribute_poll(context):
+        yield NodeItem("GeometryNodeInputNamedAttribute")
     yield NodeItem("GeometryNodeInputID")
     yield NodeItem("GeometryNodeInputIndex")
     yield NodeItem("GeometryNodeInputNormal")
@@ -358,6 +360,10 @@ def geometry_nodes_legacy_poll(context):
     return context.preferences.experimental.use_geometry_nodes_legacy
 
 
+def named_attribute_poll(context):
+    return context.preferences.experimental.use_named_attribute_nodes
+
+
 # All standard node categories currently used in nodes.
 
 shader_node_categories = [
@@ -683,6 +689,8 @@ geometry_node_categories = [
         NodeItem("GeometryNodeAttributeDomainSize"),
         NodeItem("GeometryNodeAttributeStatistic"),
         NodeItem("GeometryNodeAttributeTransfer"),
+        NodeItem("GeometryNodeStoreNamedAttribute", poll=named_attribute_poll),
+        NodeItem("GeometryNodeRemoveAttribute", poll=named_attribute_poll),
     ]),
     GeometryNodeCategory("GEO_COLOR", "Color", items=[
         NodeItem("ShaderNodeMixRGB"),