Geometry Nodes: remove empty mesh component in distribute node output

3 files changed, 18 insertions, 2 deletions

diff --git a/source/blender/blenkernel/BKE_geometry_set.hh b/source/blender/blenkernel/BKE_geometry_set.hh
index f6a58e57298..4954b1d5ab2 100644
--- a/source/blender/blenkernel/BKE_geometry_set.hh
+++ b/source/blender/blenkernel/BKE_geometry_set.hh
@@ -281,6 +281,8 @@ struct GeometrySet {
     return this->remove(Component::static_type);
   }
 
+  void keep_only(const blender::Span<GeometryComponentType> component_types);
+
   void add(const GeometryComponent &component);
 
   blender::Vector<const GeometryComponent *> get_components_for_read() const;
diff --git a/source/blender/blenkernel/intern/geometry_set.cc b/source/blender/blenkernel/intern/geometry_set.cc
index e8e2f64d6e1..400e0fda518 100644
--- a/source/blender/blenkernel/intern/geometry_set.cc
+++ b/source/blender/blenkernel/intern/geometry_set.cc
@@ -152,6 +152,19 @@ void GeometrySet::remove(const GeometryComponentType component_type)
   components_.remove(component_type);
 }
 
+/**
+ * Remove all geometry components with types that are not in the provided list.
+ */
+void GeometrySet::keep_only(const blender::Span<GeometryComponentType> component_types)
+{
+  for (auto it = components_.keys().begin(); it != components_.keys().end(); ++it) {
+    const GeometryComponentType type = *it;
+    if (!component_types.contains(type)) {
+      components_.remove(it);
+    }
+  }
+}
+
 void GeometrySet::add(const GeometryComponent &component)
 {
   BLI_assert(!components_.contains(component.type()));
diff --git a/source/blender/nodes/geometry/nodes/node_geo_distribute_points_on_faces.cc b/source/blender/nodes/geometry/nodes/node_geo_distribute_points_on_faces.cc
index 3f2541dcded..f27544cbdda 100644
--- a/source/blender/nodes/geometry/nodes/node_geo_distribute_points_on_faces.cc
+++ b/source/blender/nodes/geometry/nodes/node_geo_distribute_points_on_faces.cc
@@ -523,8 +523,6 @@ static void point_distribution_calculate(GeometrySet &geometry_set,
 
   compute_attribute_outputs(
       mesh_component, point_component, bary_coords, looptri_indices, attribute_outputs);
-
-  geometry_set.replace_mesh(nullptr);
 }
 
 static void geo_node_point_distribute_points_on_faces_exec(GeoNodeExecParams params)
@@ -551,6 +549,9 @@ static void geo_node_point_distribute_points_on_faces_exec(GeoNodeExecParams par
   geometry_set.modify_geometry_sets([&](GeometrySet &geometry_set) {
     point_distribution_calculate(
         geometry_set, selection_field, method, seed, attribute_outputs, params);
+    /* Keep instances because the original geometry set may contain instances that are processed as
+     * well. */
+    geometry_set.keep_only({GEO_COMPONENT_TYPE_POINT_CLOUD, GEO_COMPONENT_TYPE_INSTANCES});
   });
 
   params.set_output("Points", std::move(geometry_set));