Geometry Nodes: Curve Sample Node

This node allows sampling positions, tangents, and normals at any
arbitrary point along a curve. The curve can include multiple splines,
all are taken into account. The node does not yet support transferring
generic attributes like radius, because some more general tooling will
make that much more feasible and useful in different scenarios.

This is a field node, so it is evaluated in the context of a data-flow
node like "Set Position". One nice thing about that is it can easily
be used to move an entire geometry like the follow path constraint.

The point along the curve is chosen either with a factor of the total
length of the curve, or a length into the curve, the same choice used
in the curve trim node.

Differential Revision: https://developer.blender.org/D12565

1 files changed, 24 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index ae5f8d5f5da..d0bf60d5d02 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -9088,6 +9088,30 @@ static void def_geo_curve_primitive_bezier_segment(StructRNA *srna)
   RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update");
 }
 
+static void def_geo_curve_sample(StructRNA *srna)
+{
+  static EnumPropertyItem mode_items[] = {
+      {GEO_NODE_CURVE_SAMPLE_FACTOR,
+       "FACTOR",
+       0,
+       "Factor",
+       "Find sample positions on the curve using a factor of its total length"},
+      {GEO_NODE_CURVE_SAMPLE_LENGTH,
+       "LENGTH",
+       0,
+       "Length",
+       "Find sample positions on the curve using a distance from its beginning"},
+      {0, NULL, 0, NULL, NULL},
+  };
+
+  RNA_def_struct_sdna_from(srna, "NodeGeometryCurveSample", "storage");
+
+  PropertyRNA *prop = RNA_def_property(srna, "mode", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_items(prop, mode_items);
+  RNA_def_property_ui_text(prop, "Mode", "Method for sampling input");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update");
+}
+
 static void def_geo_triangulate(StructRNA *srna)
 {
   PropertyRNA *prop;