Geometry Nodes: Instance Rotation Node

A field input node for the rotation of each top-level instance transform.
The rotation can be set with the "Rotate Instances" node, but previously
could not be retrieved.

Differential Revision: https://developer.blender.org/D15131

6 files changed, 70 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index 1ff10d06b00..bd0565f4227 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -1493,6 +1493,7 @@ struct TexResult;
 #define GEO_NODE_STORE_NAMED_ATTRIBUTE 1156
 #define GEO_NODE_INPUT_NAMED_ATTRIBUTE 1157
 #define GEO_NODE_REMOVE_ATTRIBUTE 1158
+#define GEO_NODE_INPUT_INSTANCE_ROTATION 1159
 
 /** \} */
 
diff --git a/source/blender/blenkernel/intern/node.cc b/source/blender/blenkernel/intern/node.cc
index cf50e8a3b43..f37539afe55 100644
--- a/source/blender/blenkernel/intern/node.cc
+++ b/source/blender/blenkernel/intern/node.cc
@@ -4764,6 +4764,7 @@ static void registerGeometryNodes()
   register_node_type_geo_input_curve_tilt();
   register_node_type_geo_input_id();
   register_node_type_geo_input_index();
+  register_node_type_geo_input_instance_rotation();
   register_node_type_geo_input_material_index();
   register_node_type_geo_input_material();
   register_node_type_geo_input_mesh_edge_angle();
diff --git a/source/blender/nodes/NOD_geometry.h b/source/blender/nodes/NOD_geometry.h
index 064112b7efd..13ae1ac2724 100644
--- a/source/blender/nodes/NOD_geometry.h
+++ b/source/blender/nodes/NOD_geometry.h
@@ -62,6 +62,7 @@ void register_node_type_geo_input_curve_handles(void);
 void register_node_type_geo_input_curve_tilt(void);
 void register_node_type_geo_input_id(void);
 void register_node_type_geo_input_index(void);
+void register_node_type_geo_input_instance_rotation(void);
 void register_node_type_geo_input_material_index(void);
 void register_node_type_geo_input_material(void);
 void register_node_type_geo_input_mesh_edge_angle(void);
diff --git a/source/blender/nodes/NOD_static_types.h b/source/blender/nodes/NOD_static_types.h
index e0a4d241b3b..60422462173 100644
--- a/source/blender/nodes/NOD_static_types.h
+++ b/source/blender/nodes/NOD_static_types.h
@@ -318,6 +318,7 @@ DefNode(GeometryNode, GEO_NODE_INPUT_CURVE_HANDLES, 0, "INPUT_CURVE_HANDLES", In
 DefNode(GeometryNode, GEO_NODE_INPUT_CURVE_TILT, 0, "INPUT_CURVE_TILT", InputCurveTilt, "Curve Tilt", "")
 DefNode(GeometryNode, GEO_NODE_INPUT_ID, 0, "INPUT_ID", InputID, "ID", "")
 DefNode(GeometryNode, GEO_NODE_INPUT_INDEX, 0, "INDEX", InputIndex, "Index", "")
+DefNode(GeometryNode, GEO_NODE_INPUT_INSTANCE_ROTATION, 0, "INPUT_INSTANCE_ROTATION", InputInstanceRotation, "Instance Rotation", "")
 DefNode(GeometryNode, GEO_NODE_INPUT_MATERIAL_INDEX, 0, "INPUT_MATERIAL_INDEX", InputMaterialIndex, "Material Index", "")
 DefNode(GeometryNode, GEO_NODE_INPUT_MATERIAL, def_geo_input_material, "INPUT_MATERIAL", InputMaterial, "Material", "")
 DefNode(GeometryNode, GEO_NODE_INPUT_MESH_EDGE_ANGLE, 0, "MESH_EDGE_ANGLE", InputMeshEdgeAngle, "Edge Angle", "")
diff --git a/source/blender/nodes/geometry/CMakeLists.txt b/source/blender/nodes/geometry/CMakeLists.txt
index 84280c0889a..c3cfd07d4b0 100644
--- a/source/blender/nodes/geometry/CMakeLists.txt
+++ b/source/blender/nodes/geometry/CMakeLists.txt
@@ -71,6 +71,7 @@ set(SRC
   nodes/node_geo_input_curve_tilt.cc
   nodes/node_geo_input_id.cc
   nodes/node_geo_input_index.cc
+  nodes/node_geo_input_instance_rotation.cc
   nodes/node_geo_input_material.cc
   nodes/node_geo_input_material_index.cc
   nodes/node_geo_input_mesh_edge_angle.cc
diff --git a/source/blender/nodes/geometry/nodes/node_geo_input_instance_rotation.cc b/source/blender/nodes/geometry/nodes/node_geo_input_instance_rotation.cc
new file mode 100644
index 00000000000..a6d6722ae2a
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_input_instance_rotation.cc
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "node_geometry_util.hh"
+
+namespace blender::nodes::node_geo_input_instance_rotation_cc {
+
+static void node_declare(NodeDeclarationBuilder &b)
+{
+  b.add_output<decl::Vector>(N_("Rotation")).field_source();
+}
+
+class VectorFieldInput final : public GeometryFieldInput {
+ public:
+  VectorFieldInput() : GeometryFieldInput(CPPType::get<float3>(), "Rotation")
+  {
+  }
+
+  GVArray get_varray_for_context(const GeometryComponent &component,
+                                 const eAttrDomain domain,
+                                 IndexMask mask) const final
+  {
+    if (component.type() != GEO_COMPONENT_TYPE_INSTANCES) {
+      return {};
+    }
+
+    const InstancesComponent &instance_component = static_cast<const InstancesComponent &>(
+        component);
+
+    auto rotation_fn = [&](const int i) -> float3 {
+      return instance_component.instance_transforms()[i].to_euler();
+    };
+
+    return VArray<float3>::ForFunc(instance_component.instances_num(), rotation_fn);
+  }
+
+  uint64_t hash() const override
+  {
+    return 22374372;
+  }
+
+  bool is_equal_to(const fn::FieldNode &other) const override
+  {
+    return dynamic_cast<const VectorFieldInput *>(&other) != nullptr;
+  }
+};
+
+static void node_geo_exec(GeoNodeExecParams params)
+{
+  Field<float3> rotation{std::make_shared<VectorFieldInput>()};
+  params.set_output("Rotation", std::move(rotation));
+}
+
+}  // namespace blender::nodes::node_geo_input_instance_rotation_cc
+
+void register_node_type_geo_input_instance_rotation()
+{
+  namespace file_ns = blender::nodes::node_geo_input_instance_rotation_cc;
+
+  static bNodeType ntype;
+  geo_node_type_base(
+      &ntype, GEO_NODE_INPUT_INSTANCE_ROTATION, "Instance Rotation", NODE_CLASS_INPUT);
+  ntype.geometry_node_execute = file_ns::node_geo_exec;
+  ntype.declare = file_ns::node_declare;
+  nodeRegisterType(&ntype);
+}