Geometry Nodes: Fill instances separately in the curve fill node

With this commit, each referenced instance data will be converted to
a geometry instances and processed separately. This should result in
a large speedup when the instances component has many insances
referring to the same data.

This change can act as a blueprint for other nodes that need to
implement similar behavior. It adds some helper functions on the
instances component to make that easier.

Thanks to Erik Abrahamsson for a proof of concept patch.

Differential Revision: https://developer.blender.org/D12572

1 files changed, 4 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_geometry_set.hh b/source/blender/blenkernel/BKE_geometry_set.hh
index 98f5de43f84..317d513dae6 100644
--- a/source/blender/blenkernel/BKE_geometry_set.hh
+++ b/source/blender/blenkernel/BKE_geometry_set.hh
@@ -580,6 +580,9 @@ class InstancesComponent : public GeometryComponent {
 
   blender::Span<InstanceReference> references() const;
 
+  void ensure_geometry_instances();
+  GeometrySet &geometry_set_from_reference(const int reference_index);
+
   blender::Span<int> instance_reference_handles() const;
   blender::MutableSpan<int> instance_reference_handles();
   blender::MutableSpan<blender::float4x4> instance_transforms();
@@ -588,6 +591,7 @@ class InstancesComponent : public GeometryComponent {
   blender::Span<int> instance_ids() const;
 
   int instances_amount() const;
+  int references_amount() const;
 
   blender::Span<int> almost_unique_ids() const;