Geometry Nodes: Split transfer attribute node

This patch replaces the existing transfer attribute node with three
nodes, "Sample Nearest Surface", "Sample Index", and "Sample Nearest".
This follows the design in T100010, allowing for new nodes like UV
sampling in the future. There is versioning so the new nodes replace
the old ones and are relinked as necessary.

The "Sample Nearest Surface" node is meant for the more complex
sampling algorithms that only work on meshes and interpolate
values inside of faces.

The new "Sample Index" just retrieves attributes from a geometry at
specific indices. It doesn't have implicit behavior like the old
transfer mode, which should make it more predictable. In order to not
change the behavior from existing files, the node has a has a "Clamp",
which is off by default for consistency with the "Field at Index" node.

The "Sample Nearest" node returns the index of the nearest element
on a geometry. It can be combined with the "Sample Index" node for
the same functionality as the old transfer node. This node can support
curves in the future.

Backwards compatibility is handled by versioning, but old versions can
not understand these nodes. The warning from 680fa8a523e0 should make
this explicit in 3.3 and earlier.

Differential Revision: https://developer.blender.org/D15909

1 files changed, 3 insertions, 1 deletions

diff --git a/source/blender/blenkernel/intern/node.cc b/source/blender/blenkernel/intern/node.cc
index e5eb7a6c59a..1c7b1b9fa3e 100644
--- a/source/blender/blenkernel/intern/node.cc
+++ b/source/blender/blenkernel/intern/node.cc
@@ -4800,6 +4800,9 @@ static void registerGeometryNodes()
   register_node_type_geo_realize_instances();
   register_node_type_geo_remove_attribute();
   register_node_type_geo_rotate_instances();
+  register_node_type_geo_sample_index();
+  register_node_type_geo_sample_nearest_surface();
+  register_node_type_geo_sample_nearest();
   register_node_type_geo_scale_elements();
   register_node_type_geo_scale_instances();
   register_node_type_geo_separate_components();
@@ -4821,7 +4824,6 @@ static void registerGeometryNodes()
   register_node_type_geo_string_to_curves();
   register_node_type_geo_subdivision_surface();
   register_node_type_geo_switch();
-  register_node_type_geo_transfer_attribute();
   register_node_type_geo_transform();
   register_node_type_geo_translate_instances();
   register_node_type_geo_triangulate();