node_geo_mesh_to_volume.cc

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/* SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#include "node_geometry_util.hh"
 
#include "BKE_lib_id.hh"
#include "BKE_mesh.hh"
 
#include "GEO_mesh_to_volume.hh"
 
#include "NOD_rna_define.hh"
 
#include "UI_interface.hh"
#include "UI_resources.hh"
 
namespace blender::nodes::node_geo_mesh_to_volume_cc {
 
NODE_STORAGE_FUNCS(NodeGeometryMeshToVolume)
 
static void node_declare(NodeDeclarationBuilder &b)
{
  b.add_input<decl::Geometry>("Mesh").supported_type(GeometryComponent::Type::Mesh);
  b.add_input<decl::Float>("Density").default_value(1.0f).min(0.01f).max(FLT_MAX);
  auto &voxel_size = b.add_input<decl::Float>("Voxel Size")
                         .default_value(0.3f)
                         .min(0.01f)
                         .max(FLT_MAX)
                         .subtype(PROP_DISTANCE);
  auto &voxel_amount =
      b.add_input<decl::Float>("Voxel Amount").default_value(64.0f).min(0.0f).max(FLT_MAX);
  b.add_input<decl::Float>("Interior Band Width")
      .default_value(0.2f)
      .min(0.0001f)
      .max(FLT_MAX)
      .subtype(PROP_DISTANCE)
      .description("Width of the gradient inside of the mesh");
  b.add_output<decl::Geometry>("Volume").translation_context(BLT_I18NCONTEXT_ID_ID);
 
  const bNode *node = b.node_or_null();
  if (node != nullptr) {
    const NodeGeometryMeshToVolume &data = node_storage(*node);
    voxel_size.available(data.resolution_mode == MESH_TO_VOLUME_RESOLUTION_MODE_VOXEL_SIZE);
    voxel_amount.available(data.resolution_mode == MESH_TO_VOLUME_RESOLUTION_MODE_VOXEL_AMOUNT);
  }
}
 
static void node_layout(uiLayout *layout, bContext * /*C*/, PointerRNA *ptr)
{
  uiLayoutSetPropSep(layout, true);
  uiLayoutSetPropDecorate(layout, false);
  uiItemR(layout, ptr, "resolution_mode", UI_ITEM_NONE, IFACE_("Resolution"), ICON_NONE);
}
 
static void node_init(bNodeTree * /*tree*/, bNode *node)
{
  NodeGeometryMeshToVolume *data = MEM_cnew<NodeGeometryMeshToVolume>(__func__);
  data->resolution_mode = MESH_TO_VOLUME_RESOLUTION_MODE_VOXEL_AMOUNT;
  node->storage = data;
}
 
#ifdef WITH_OPENVDB
 
static Volume *create_volume_from_mesh(const Mesh &mesh, GeoNodeExecParams &params)
{
  const NodeGeometryMeshToVolume &storage =
      *(const NodeGeometryMeshToVolume *)params.node().storage;
 
  const float density = params.get_input<float>("Density");
  const float interior_band_width = params.get_input<float>("Interior Band Width");
 
  geometry::MeshToVolumeResolution resolution;
  resolution.mode = (MeshToVolumeModifierResolutionMode)storage.resolution_mode;
  if (resolution.mode == MESH_TO_VOLUME_RESOLUTION_MODE_VOXEL_AMOUNT) {
    resolution.settings.voxel_amount = params.get_input<float>("Voxel Amount");
    if (resolution.settings.voxel_amount <= 0.0f) {
      return nullptr;
    }
  }
  else if (resolution.mode == MESH_TO_VOLUME_RESOLUTION_MODE_VOXEL_SIZE) {
    resolution.settings.voxel_size = params.get_input<float>("Voxel Size");
    if (resolution.settings.voxel_size <= 0.0f) {
      return nullptr;
    }
  }
 
  if (mesh.verts_num == 0 || mesh.faces_num == 0) {
    return nullptr;
  }
 
  const float4x4 mesh_to_volume_space_transform = float4x4::identity();
 
  const float voxel_size = geometry::volume_compute_voxel_size(
      params.depsgraph(),
      [&]() { return *mesh.bounds_min_max(); },
      resolution,
      0.0f,
      mesh_to_volume_space_transform);
 
  Volume *volume = reinterpret_cast<Volume *>(BKE_id_new_nomain(ID_VO, nullptr));
 
  /* Convert mesh to grid and add to volume. */
  geometry::fog_volume_grid_add_from_mesh(volume,
                                          "density",
                                          mesh.vert_positions(),
                                          mesh.corner_verts(),
                                          mesh.corner_tris(),
                                          mesh_to_volume_space_transform,
                                          voxel_size,
                                          interior_band_width,
                                          density);
 
  return volume;
}
 
#endif /* WITH_OPENVDB */
 
static void node_geo_exec(GeoNodeExecParams params)
{
#ifdef WITH_OPENVDB
  GeometrySet geometry_set(params.extract_input<GeometrySet>("Mesh"));
  geometry_set.modify_geometry_sets([&](GeometrySet &geometry_set) {
    if (geometry_set.has_mesh()) {
      Volume *volume = create_volume_from_mesh(*geometry_set.get_mesh(), params);
      geometry_set.replace_volume(volume);
      geometry_set.keep_only_during_modify({GeometryComponent::Type::Volume});
    }
  });
  params.set_output("Volume", std::move(geometry_set));
#else
  node_geo_exec_with_missing_openvdb(params);
  return;
#endif
}
 
static void node_rna(StructRNA *srna)
{
  static EnumPropertyItem resolution_mode_items[] = {
      {MESH_TO_VOLUME_RESOLUTION_MODE_VOXEL_AMOUNT,
       "VOXEL_AMOUNT",
       0,
       "Amount",
       "Desired number of voxels along one axis"},
      {MESH_TO_VOLUME_RESOLUTION_MODE_VOXEL_SIZE,
       "VOXEL_SIZE",
       0,
       "Size",
       "Desired voxel side length"},
      {0, nullptr, 0, nullptr, nullptr},
  };
 
  RNA_def_node_enum(srna,
                    "resolution_mode",
                    "Resolution Mode",
                    "How the voxel size is specified",
                    resolution_mode_items,
                    NOD_storage_enum_accessors(resolution_mode),
                    MESH_TO_VOLUME_RESOLUTION_MODE_VOXEL_AMOUNT);
}
 
static void node_register()
{
  static blender::bke::bNodeType ntype;
 
  geo_node_type_base(&ntype, GEO_NODE_MESH_TO_VOLUME, "Mesh to Volume", NODE_CLASS_GEOMETRY);
  ntype.declare = node_declare;
  bke::node_type_size(&ntype, 200, 120, 700);
  ntype.initfunc = node_init;
  ntype.geometry_node_execute = node_geo_exec;
  ntype.draw_buttons = node_layout;
  blender::bke::node_type_storage(
      &ntype, "NodeGeometryMeshToVolume", node_free_standard_storage, node_copy_standard_storage);
  blender::bke::node_register_type(&ntype);
 
  node_rna(ntype.rna_ext.srna);
}
NOD_REGISTER_NODE(node_register)
 
}  // namespace blender::nodes::node_geo_mesh_to_volume_cc