Geometry Nodes: new Geometry to Instance node

This adds a new Geometry to Instance node that turns every
connected input geometry into an instance. Those instances
can for example be used in the Instance on Points node.

Differential Revision: https://developer.blender.org/D13500

1 files changed, 55 insertions, 0 deletions

diff --git a/source/blender/nodes/geometry/nodes/node_geo_geometry_to_instance.cc b/source/blender/nodes/geometry/nodes/node_geo_geometry_to_instance.cc
new file mode 100644
index 00000000000..7faf104737f
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_geometry_to_instance.cc
@@ -0,0 +1,55 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "node_geometry_util.hh"
+
+namespace blender::nodes::node_geo_geometry_to_instance_cc {
+
+static void node_declare(NodeDeclarationBuilder &b)
+{
+  b.add_input<decl::Geometry>(N_("Geometry")).multi_input();
+  b.add_output<decl::Geometry>(N_("Instances"));
+}
+
+static void node_geo_exec(GeoNodeExecParams params)
+{
+  Vector<GeometrySet> geometries = params.extract_multi_input<GeometrySet>("Geometry");
+  GeometrySet instances_geometry;
+  InstancesComponent &instances_component =
+      instances_geometry.get_component_for_write<InstancesComponent>();
+  for (GeometrySet &geometry : geometries) {
+    geometry.ensure_owns_direct_data();
+    const int handle = instances_component.add_reference(std::move(geometry));
+    instances_component.add_instance(handle, float4x4::identity());
+  }
+  params.set_output("Instances", std::move(instances_geometry));
+}
+
+}  // namespace blender::nodes::node_geo_geometry_to_instance_cc
+
+void register_node_type_geo_geometry_to_instance()
+{
+  namespace file_ns = blender::nodes::node_geo_geometry_to_instance_cc;
+
+  static bNodeType ntype;
+
+  geo_node_type_base(
+      &ntype, GEO_NODE_GEOMETRY_TO_INSTANCE, "Geometry to Instance", NODE_CLASS_GEOMETRY, 0);
+  node_type_size(&ntype, 160, 100, 300);
+  ntype.geometry_node_execute = file_ns::node_geo_exec;
+  ntype.declare = file_ns::node_declare;
+  nodeRegisterType(&ntype);
+}