Geometry Nodes: Fields transfer attribute node

This commit adds an updated version of the old attribute transfer node.
It works like a function node, so it works in the context of a
geometry, with a simple data output.

The "Nearest" mode finds the nearest element of the specified domain on
the target geometry and copies the value directly from the target input.

The "Nearest Face Interpolated" finds the nearest point on anywhere on
the surface of the target mesh and linearly interpolates the value on
the target from the face's corners.

The node also has a new "Index" mode, which can pick data from specific
indices on the target geometry. The implicit default is to do a simple
copy from the target geometry, but any indices could be used. It is also
possible to use a single value for the index to to retrieve a single
value from an attribute at a certain index.

Differential Revision: https://developer.blender.org/D12785

1 files changed, 60 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index f52173b45d4..3ca5e562a5e 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -2181,6 +2181,19 @@ static const EnumPropertyItem *rna_GeometryNodeAttributeFill_type_itemf(bContext
   return itemf_function_check(rna_enum_attribute_type_items, attribute_fill_type_supported);
 }
 
+static bool transfer_attribute_type_supported(const EnumPropertyItem *item)
+{
+  return ELEM(
+      item->value, CD_PROP_FLOAT, CD_PROP_FLOAT3, CD_PROP_COLOR, CD_PROP_BOOL, CD_PROP_INT32);
+}
+
+static const EnumPropertyItem *rna_NodeGeometryTransferAttribute_type_itemf(
+    bContext *UNUSED(C), PointerRNA *UNUSED(ptr), PropertyRNA *UNUSED(prop), bool *r_free)
+{
+  *r_free = true;
+  return itemf_function_check(rna_enum_attribute_type_items, transfer_attribute_type_supported);
+}
+
 static bool attribute_statistic_type_supported(const EnumPropertyItem *item)
 {
   return ELEM(item->value, CD_PROP_FLOAT, CD_PROP_FLOAT3);
@@ -10643,6 +10656,53 @@ static void def_geo_attribute_transfer(StructRNA *srna)
   RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
 }
 
+static void def_geo_transfer_attribute(StructRNA *srna)
+{
+  static EnumPropertyItem mapping_items[] = {
+      {GEO_NODE_ATTRIBUTE_TRANSFER_NEAREST_FACE_INTERPOLATED,
+       "NEAREST_FACE_INTERPOLATED",
+       0,
+       "Nearest Face Interpolated",
+       "Transfer the attribute from the nearest face on a surface (loose points and edges are "
+       "ignored)"},
+      {GEO_NODE_ATTRIBUTE_TRANSFER_NEAREST,
+       "NEAREST",
+       0,
+       "Nearest",
+       "Transfer the element from the nearest element (using face and edge centers for the "
+       "distance computation)"},
+      {GEO_NODE_ATTRIBUTE_TRANSFER_INDEX,
+       "INDEX",
+       0,
+       "Index",
+       "Transfer the data from the element with the corresponding index in the target geometry"},
+      {0, NULL, 0, NULL, NULL},
+  };
+
+  PropertyRNA *prop;
+
+  RNA_def_struct_sdna_from(srna, "NodeGeometryTransferAttribute", "storage");
+
+  prop = RNA_def_property(srna, "mapping", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_sdna(prop, NULL, "mode");
+  RNA_def_property_enum_items(prop, mapping_items);
+  RNA_def_property_ui_text(prop, "Mapping", "Mapping between geometries");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update");
+
+  prop = RNA_def_property(srna, "data_type", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_items(prop, rna_enum_attribute_type_items);
+  RNA_def_property_enum_funcs(prop, NULL, NULL, "rna_NodeGeometryTransferAttribute_type_itemf");
+  RNA_def_property_enum_default(prop, CD_PROP_FLOAT);
+  RNA_def_property_ui_text(prop, "Data Type", "The type for the source and result data");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update");
+
+  prop = RNA_def_property(srna, "domain", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_items(prop, rna_enum_attribute_domain_items);
+  RNA_def_property_enum_default(prop, ATTR_DOMAIN_POINT);
+  RNA_def_property_ui_text(prop, "Domain", "The domain to use on the target geometry");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+}
+
 static void def_geo_input_material(StructRNA *srna)
 {
   PropertyRNA *prop;