Geometry Nodes: Updated Subdivision Surface Node

Replaces the old Subdivision Surface Node.

Changes:
 - Removes implicit instance realization, instead the node runs once
   per unique instance.
 - "Use Creases" becomes a crease field input applied to edges.
   The values are clamped between zero and one.

Addresses T91763

Differential Revision: https://developer.blender.org/D12830

release/scripts/startup/nodeitems_builtins.py

@@ -148,6 +148,7 @@ def mesh_node_items(context):
     yield NodeItem("GeometryNodeMeshToPoints")
     yield NodeItem("GeometryNodeSplitEdges")
     yield NodeItem("GeometryNodeSubdivideMesh")
+    yield NodeItem("GeometryNodeSubdivisionSurface")
     yield NodeItem("GeometryNodeTriangulate")
     yield NodeItemCustom(draw=lambda self, layout, context: layout.separator())
     yield NodeItem("GeometryNodeInputShadeSmooth")

source/blender/blenkernel/BKE_node.h

@@ -1538,6 +1538,7 @@ int ntreeTexExecTree(struct bNodeTree *ntree,
 #define GEO_NODE_SPLIT_EDGES 1123
 #define GEO_NODE_MESH_TO_CURVE 1124
 #define GEO_NODE_TRANSFER_ATTRIBUTE 1125
+#define GEO_NODE_SUBDIVISION_SURFACE 1126
 
 /** \} */
 

source/blender/blenkernel/intern/node.cc

@@ -5726,6 +5726,7 @@ static void registerGeometryNodes()
   register_node_type_geo_legacy_select_by_handle_type();
   register_node_type_geo_legacy_curve_subdivide();
   register_node_type_geo_legacy_edge_split();
+  register_node_type_geo_legacy_subdivision_surface();
 
   register_node_type_geo_align_rotation_to_vector();
   register_node_type_geo_attribute_capture();

source/blender/nodes/CMakeLists.txt

@@ -278,6 +278,7 @@ set(SRC
   geometry/nodes/node_geo_triangulate.cc
   geometry/nodes/node_geo_viewer.cc
   geometry/nodes/node_geo_volume_to_mesh.cc
+  geometry/nodes/node_geo_subdivision_surface.cc
 
   geometry/node_geometry_exec.cc
   geometry/node_geometry_tree.cc

source/blender/nodes/NOD_geometry.h

@@ -43,6 +43,7 @@ void register_node_type_geo_legacy_curve_reverse(void);
 void register_node_type_geo_legacy_select_by_handle_type(void);
 void register_node_type_geo_legacy_curve_subdivide(void);
 void register_node_type_geo_legacy_edge_split(void);
+void register_node_type_geo_legacy_subdivision_surface(void);
 
 void register_node_type_geo_align_rotation_to_vector(void);
 void register_node_type_geo_attribute_capture(void);

source/blender/nodes/NOD_static_types.h

@@ -399,6 +399,7 @@ DefNode(GeometryNode, GEO_NODE_SET_SPLINE_CYCLIC, 0, "SET_SPLINE_CYCLIC", SetSpl
 DefNode(GeometryNode, GEO_NODE_SET_SPLINE_RESOLUTION, 0, "SET_SPLINE_RESOLUTION", SetSplineResolution, "Set Spline Resolution", "")
 DefNode(GeometryNode, GEO_NODE_STRING_JOIN, 0, "STRING_JOIN", StringJoin, "Join Strings", "")
 DefNode(GeometryNode, GEO_NODE_STRING_TO_CURVES, def_geo_string_to_curves, "STRING_TO_CURVES", StringToCurves, "String to Curves", "")
+DefNode(GeometryNode, GEO_NODE_SUBDIVISION_SURFACE, def_geo_subdivision_surface, "SUBDIVISION_SURFACE", SubdivisionSurface, "Subdivision Surface", "")
 DefNode(GeometryNode, GEO_NODE_SWITCH, def_geo_switch, "SWITCH", Switch, "Switch", "")
 DefNode(GeometryNode, GEO_NODE_TRANSFER_ATTRIBUTE, def_geo_transfer_attribute, "ATTRIBUTE_TRANSFER", AttributeTransfer, "Transfer Attribute", "")
 DefNode(GeometryNode, GEO_NODE_TRANSFORM, 0, "TRANSFORM", Transform, "Transform", "")

source/blender/nodes/geometry/nodes/legacy/node_geo_subdivision_surface.cc

@@ -128,7 +128,7 @@ static void geo_node_subdivision_surface_exec(GeoNodeExecParams params)
 
 }  // namespace blender::nodes
 
-void register_node_type_geo_subdivision_surface()
+void register_node_type_geo_legacy_subdivision_surface()
 {
   static bNodeType ntype;
 

source/blender/nodes/geometry/nodes/node_geo_subdivision_surface.cc

@@ -0,0 +1,169 @@
+/*
+ * 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 "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+#include "DNA_modifier_types.h"
+
+#include "BKE_mesh.h"
+#include "BKE_subdiv.h"
+#include "BKE_subdiv_mesh.h"
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "node_geometry_util.hh"
+
+namespace blender::nodes {
+
+static void geo_node_subdivision_surface_declare(NodeDeclarationBuilder &b)
+{
+  b.add_input<decl::Geometry>("Geometry");
+  b.add_input<decl::Int>("Level").default_value(1).min(0).max(6);
+  b.add_input<decl::Float>("Crease")
+      .default_value(0.0f)
+      .min(0.0f)
+      .max(1.0f)
+      .supports_field()
+      .subtype(PROP_FACTOR);
+  b.add_output<decl::Geometry>("Geometry");
+}
+
+static void geo_node_subdivision_surface_layout(uiLayout *layout,
+                                                bContext *UNUSED(C),
+                                                PointerRNA *ptr)
+{
+#ifdef WITH_OPENSUBDIV
+  uiLayoutSetPropSep(layout, true);
+  uiLayoutSetPropDecorate(layout, false);
+  uiItemR(layout, ptr, "uv_smooth", 0, nullptr, ICON_NONE);
+  uiItemR(layout, ptr, "boundary_smooth", 0, nullptr, ICON_NONE);
+#else
+  UNUSED_VARS(layout, ptr);
+#endif
+}
+
+static void geo_node_subdivision_surface_init(bNodeTree *UNUSED(ntree), bNode *node)
+{
+  NodeGeometrySubdivisionSurface *data = (NodeGeometrySubdivisionSurface *)MEM_callocN(
+      sizeof(NodeGeometrySubdivisionSurface), __func__);
+  data->uv_smooth = SUBSURF_UV_SMOOTH_PRESERVE_BOUNDARIES;
+  data->boundary_smooth = SUBSURF_BOUNDARY_SMOOTH_ALL;
+  node->storage = data;
+}
+
+static void geo_node_subdivision_surface_exec(GeoNodeExecParams params)
+{
+  GeometrySet geometry_set = params.extract_input<GeometrySet>("Geometry");
+
+  Field<float> crease_field = params.extract_input<Field<float>>("Crease");
+
+  const NodeGeometrySubdivisionSurface &storage =
+      *(const NodeGeometrySubdivisionSurface *)params.node().storage;
+  const int uv_smooth = storage.uv_smooth;
+  const int boundary_smooth = storage.boundary_smooth;
+  const int subdiv_level = clamp_i(params.extract_input<int>("Level"), 0, 30);
+
+  /* Only process subdivision if level is greater than 0. */
+  if (subdiv_level == 0) {
+    params.set_output("Geometry", std::move(geometry_set));
+    return;
+  }
+
+#ifndef WITH_OPENSUBDIV
+  params.error_message_add(NodeWarningType::Error,
+                           TIP_("Disabled, Blender was compiled without OpenSubdiv"));
+#else
+  geometry_set.modify_geometry_sets([&](GeometrySet &geometry_set) {
+    if (!geometry_set.has_mesh()) {
+      return;
+    }
+
+    MeshComponent &mesh_component = geometry_set.get_component_for_write<MeshComponent>();
+    AttributeDomain domain = ATTR_DOMAIN_EDGE;
+    GeometryComponentFieldContext field_context{mesh_component, domain};
+    const int domain_size = mesh_component.attribute_domain_size(domain);
+
+    FieldEvaluator evaluator(field_context, domain_size);
+    evaluator.add(crease_field);
+    evaluator.evaluate();
+    const VArray<float> &creases = evaluator.get_evaluated<float>(0);
+
+    OutputAttribute_Typed<float> crease = mesh_component.attribute_try_get_for_output_only<float>(
+        "crease", domain);
+    MutableSpan<float> crease_span = crease.as_span();
+    for (auto i : creases.index_range()) {
+      crease_span[i] = std::clamp(creases[i], 0.0f, 1.0f);
+    }
+    crease.save();
+
+    /* Initialize mesh settings. */
+    SubdivToMeshSettings mesh_settings;
+    mesh_settings.resolution = (1 << subdiv_level) + 1;
+    mesh_settings.use_optimal_display = false;
+
+    /* Initialize subdivision settings. */
+    SubdivSettings subdiv_settings;
+    subdiv_settings.is_simple = false;
+    subdiv_settings.is_adaptive = false;
+    subdiv_settings.use_creases = !(creases.is_single() && creases.get_internal_single() == 0.0f);
+    subdiv_settings.level = subdiv_level;
+
+    subdiv_settings.vtx_boundary_interpolation =
+        BKE_subdiv_vtx_boundary_interpolation_from_subsurf(boundary_smooth);
+    subdiv_settings.fvar_linear_interpolation = BKE_subdiv_fvar_interpolation_from_uv_smooth(
+        uv_smooth);
+
+    Mesh *mesh_in = mesh_component.get_for_write();
+
+    /* Apply subdivision to mesh. */
+    Subdiv *subdiv = BKE_subdiv_update_from_mesh(nullptr, &subdiv_settings, mesh_in);
+
+    /* In case of bad topology, skip to input mesh. */
+    if (subdiv == nullptr) {
+      return;
+    }
+
+    Mesh *mesh_out = BKE_subdiv_to_mesh(subdiv, &mesh_settings, mesh_in);
+    BKE_mesh_normals_tag_dirty(mesh_out);
+
+    mesh_component.replace(mesh_out);
+
+    BKE_subdiv_free(subdiv);
+  });
+#endif
+  params.set_output("Geometry", std::move(geometry_set));
+}
+
+}  // namespace blender::nodes
+
+void register_node_type_geo_subdivision_surface()
+{
+  static bNodeType ntype;
+
+  geo_node_type_base(
+      &ntype, GEO_NODE_SUBDIVISION_SURFACE, "Subdivision Surface", NODE_CLASS_GEOMETRY, 0);
+  ntype.declare = blender::nodes::geo_node_subdivision_surface_declare;
+  ntype.geometry_node_execute = blender::nodes::geo_node_subdivision_surface_exec;
+  ntype.draw_buttons = blender::nodes::geo_node_subdivision_surface_layout;
+  node_type_init(&ntype, blender::nodes::geo_node_subdivision_surface_init);
+  node_type_size_preset(&ntype, NODE_SIZE_MIDDLE);
+  node_type_storage(&ntype,
+                    "NodeGeometrySubdivisionSurface",
+                    node_free_standard_storage,
+                    node_copy_standard_storage);
+  nodeRegisterType(&ntype);
+}