Add Chromium-only Blender WebEngine parity work

blender-5.2.0/intern/cycles/scene/mesh.cpp

@@ -0,0 +1,930 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: Apache-2.0 */
+
+#include <algorithm>
+
+#include "bvh/build.h"
+#include "bvh/bvh.h"
+
+#include "device/device.h"
+
+#include "scene/attribute.h"
+#include "scene/mesh.h"
+#include "scene/object.h"
+#include "scene/scene.h"
+#include "scene/shader_graph.h"
+
+#include "subd/split.h"
+
+#include "util/log.h"
+#include "util/set.h"
+
+#include "mikktspace.hh"
+
+CCL_NAMESPACE_BEGIN
+
+/* Tangent Space */
+
+struct MikkMeshWrapper {
+  MikkMeshWrapper(const Mesh *mesh,
+                  const packed_normal *vertex_normal,
+                  const packed_normal *corner_normal,
+                  const float2 *uv,
+                  packed_float3 *tangent,
+                  float *tangent_sign)
+      : mesh(mesh),
+        position(mesh->get_position()),
+        vertex_normal(vertex_normal),
+        corner_normal(corner_normal),
+        uv(uv),
+        tangent(tangent),
+        tangent_sign(tangent_sign)
+  {
+  }
+
+  int GetNumFaces()
+  {
+    return mesh->num_triangles();
+  }
+
+  int GetNumVerticesOfFace(const int /*face_num*/)
+  {
+    return 3;
+  }
+
+  int CornerIndex(const int face_num, const int vert_num)
+  {
+    return face_num * 3 + vert_num;
+  }
+
+  int VertexIndex(const int face_num, const int vert_num)
+  {
+    const int corner = CornerIndex(face_num, vert_num);
+    return mesh->get_triangles()[corner];
+  }
+
+  mikk::float3 GetPosition(const int face_num, const int vert_num)
+  {
+    const float3 vP = float3(position[VertexIndex(face_num, vert_num)]);
+    return mikk::float3(vP.x, vP.y, vP.z);
+  }
+
+  mikk::float3 GetTexCoord(const int face_num, const int vert_num)
+  {
+    /* TODO: Check whether introducing a template boolean in order to
+     * turn this into a constexpr is worth it. */
+    if (has_uv()) {
+      const int corner_index = CornerIndex(face_num, vert_num);
+      const float2 tfuv = uv[corner_index];
+      return mikk::float3(tfuv.x, tfuv.y, 1.0f);
+    }
+    /* revert to vertex position */
+    const float3 vP = float3(position[VertexIndex(face_num, vert_num)]);
+    const float2 uv = map_to_sphere(vP);
+    return mikk::float3(uv.x, uv.y, 1.0f);
+  }
+
+  mikk::float3 GetNormal(const int face_num, const int vert_num)
+  {
+    float3 vN;
+    if (mesh->get_smooth()[face_num]) {
+      vN = ((corner_normal) ? corner_normal[CornerIndex(face_num, vert_num)] :
+                              vertex_normal[VertexIndex(face_num, vert_num)])
+               .decode();
+    }
+    else {
+      const Mesh::Triangle tri = mesh->get_triangle(face_num);
+      vN = tri.compute_normal(position);
+    }
+    return mikk::float3(vN.x, vN.y, vN.z);
+  }
+
+  void SetTangentSpace(const int face_num, const int vert_num, mikk::float3 T, bool orientation)
+  {
+    const int corner_index = CornerIndex(face_num, vert_num);
+    tangent[corner_index] = packed_float3(make_float3(T.x, T.y, T.z));
+    if (tangent_sign != nullptr) {
+      tangent_sign[corner_index] = orientation ? 1.0f : -1.0f;
+    }
+  }
+
+  bool has_uv() const
+  {
+    return uv != nullptr;
+  }
+
+  const Mesh *mesh;
+  const packed_float3 *position;
+
+  const packed_normal *vertex_normal;
+  const packed_normal *corner_normal;
+  const float2 *uv;
+
+  packed_float3 *tangent;
+  float *tangent_sign;
+};
+
+static void mikk_compute_tangents(Attribute *attr_uv,
+                                  Mesh *mesh,
+                                  const bool need_sign,
+                                  const AttributeStandard tangent_std,
+                                  const AttributeStandard tangent_sign_std,
+                                  const char *tangent_postfix,
+                                  const char *tangent_sign_postfix)
+{
+  /* Create tangent attributes. */
+  AttributeSet &attributes = mesh->attributes;
+
+  Attribute *attr_vN = attributes.find(ATTR_STD_VERTEX_NORMAL);
+  Attribute *attr_cN = attributes.find(ATTR_STD_CORNER_NORMAL);
+  if (attr_vN == nullptr && attr_cN == nullptr) {
+    /* no normals */
+    return;
+  }
+
+  const packed_normal *vertex_normal = attr_vN ? attr_vN->data<packed_normal>() : nullptr;
+  const packed_normal *corner_normal = attr_cN ? attr_cN->data<packed_normal>() : nullptr;
+  const float2 *uv = (attr_uv) ? attr_uv->data<float2>() : nullptr;
+
+  const ustring name = ustring((attr_uv) ? attr_uv->name.string() + tangent_postfix :
+                                           Attribute::standard_name(tangent_std));
+  Attribute *attr;
+  if (attr_uv == nullptr || attr_uv->std == ATTR_STD_UV) {
+    attr = attributes.add(tangent_std, name);
+  }
+  else {
+    attr = attributes.add(name, TypeVector, ATTR_ELEMENT_CORNER);
+  }
+  packed_float3 *tangent = attr->data_for_write<packed_float3>();
+  /* Create bitangent sign attribute. */
+  float *tangent_sign = nullptr;
+  if (need_sign) {
+    const ustring name_sign = ustring((attr_uv) ? attr_uv->name.string() + tangent_sign_postfix :
+                                                  Attribute::standard_name(tangent_sign_std));
+    Attribute *attr_sign;
+    if (attr_uv == nullptr || attr_uv->std == ATTR_STD_UV) {
+      attr_sign = attributes.add(tangent_sign_std, name_sign);
+    }
+    else {
+      attr_sign = attributes.add(name_sign, TypeFloat, ATTR_ELEMENT_CORNER);
+    }
+    tangent_sign = attr_sign->data_for_write<float>();
+  }
+
+  MikkMeshWrapper userdata(mesh, vertex_normal, corner_normal, uv, tangent, tangent_sign);
+  /* Compute tangents. */
+  mikk::Mikktspace(userdata).genTangSpace();
+}
+
+/* Triangle */
+
+void Mesh::Triangle::bounds_grow(const packed_float3 *verts, BoundBox &bounds) const
+{
+  bounds.grow(verts[v[0]]);
+  bounds.grow(verts[v[1]]);
+  bounds.grow(verts[v[2]]);
+}
+
+void Mesh::Triangle::motion_verts(const Attribute *attr_P,
+                                  const size_t num_steps,
+                                  const float time,
+                                  float3 r_verts[3]) const
+{
+  /* Figure out which steps we need to fetch and their interpolation factor. */
+  const size_t max_step = num_steps - 1;
+  const size_t step = min((size_t)(time * max_step), max_step - 1);
+  const float t = time * max_step - step;
+  /* Fetch vertex coordinates. */
+  float3 curr_verts[3];
+  float3 next_verts[3];
+  verts_for_step(attr_P, step, curr_verts);
+  verts_for_step(attr_P, step + 1, next_verts);
+  /* Interpolate between steps. */
+  r_verts[0] = (1.0f - t) * curr_verts[0] + t * next_verts[0];
+  r_verts[1] = (1.0f - t) * curr_verts[1] + t * next_verts[1];
+  r_verts[2] = (1.0f - t) * curr_verts[2] + t * next_verts[2];
+}
+
+void Mesh::Triangle::verts_for_step(const Attribute *attr_P,
+                                    const size_t step,
+                                    float3 r_verts[3]) const
+{
+  const packed_float3 *vert_step = attr_P->data_at_time_step<packed_float3>(
+      step, attr_P->num_motion_steps());
+  r_verts[0] = vert_step[v[0]];
+  r_verts[1] = vert_step[v[1]];
+  r_verts[2] = vert_step[v[2]];
+}
+
+float3 Mesh::Triangle::compute_normal(const packed_float3 *verts) const
+{
+  const float3 v0 = verts[v[0]];
+  const float3 v1 = verts[v[1]];
+  const float3 v2 = verts[v[2]];
+  const float3 norm = cross(v1 - v0, v2 - v0);
+  const float normlen = len(norm);
+  if (normlen == 0.0f) {
+    return make_float3(1.0f, 0.0f, 0.0f);
+  }
+  return norm / normlen;
+}
+
+bool Mesh::Triangle::valid(const packed_float3 *verts) const
+{
+  return isfinite_safe(float3(verts[v[0]])) && isfinite_safe(float3(verts[v[1]])) &&
+         isfinite_safe(float3(verts[v[2]]));
+}
+
+/* SubdFace */
+
+float3 Mesh::SubdFace::normal(const Mesh *mesh) const
+{
+  const packed_float3 *verts =
+      mesh->subd_attributes.find(ATTR_STD_POSITION)->data<packed_float3>();
+  const float3 v0 = verts[mesh->subd_face_corners[start_corner + 0]];
+  const float3 v1 = verts[mesh->subd_face_corners[start_corner + 1]];
+  const float3 v2 = verts[mesh->subd_face_corners[start_corner + 2]];
+
+  return safe_normalize(cross(v1 - v0, v2 - v0));
+}
+
+size_t Mesh::num_verts() const
+{
+  const Attribute *attr = attributes.find(ATTR_STD_POSITION);
+  return attr ? attr->size : 0;
+}
+
+/* Mesh */
+
+NODE_DEFINE(Mesh)
+{
+  NodeType *type = NodeType::add("mesh", create, NodeType::NONE, Geometry::get_node_base_type());
+
+  SOCKET_INT_ARRAY(triangles, "Triangles", array<int>());
+  SOCKET_INT_ARRAY(shader, "Shader", array<int>());
+  SOCKET_BOOLEAN_ARRAY(smooth, "Smooth", array<bool>());
+
+  static NodeEnum subdivision_type_enum;
+  subdivision_type_enum.insert("none", SUBDIVISION_NONE);
+  subdivision_type_enum.insert("linear", SUBDIVISION_LINEAR);
+  subdivision_type_enum.insert("catmull_clark", SUBDIVISION_CATMULL_CLARK);
+  SOCKET_ENUM(subdivision_type, "Subdivision Type", subdivision_type_enum, SUBDIVISION_NONE);
+
+  static NodeEnum subdivision_boundary_interpolation_enum;
+  subdivision_boundary_interpolation_enum.insert("none", SUBDIVISION_BOUNDARY_NONE);
+  subdivision_boundary_interpolation_enum.insert("edge_only", SUBDIVISION_BOUNDARY_EDGE_ONLY);
+  subdivision_boundary_interpolation_enum.insert("edge_and_corner",
+                                                 SUBDIVISION_BOUNDARY_EDGE_AND_CORNER);
+  SOCKET_ENUM(subdivision_boundary_interpolation,
+              "Subdivision Boundary Interpolation",
+              subdivision_boundary_interpolation_enum,
+              SUBDIVISION_BOUNDARY_EDGE_AND_CORNER);
+
+  static NodeEnum subdivision_fvar_interpolation_enum;
+  subdivision_fvar_interpolation_enum.insert("none", SUBDIVISION_FVAR_LINEAR_NONE);
+  subdivision_fvar_interpolation_enum.insert("corners_only", SUBDIVISION_FVAR_LINEAR_CORNERS_ONLY);
+  subdivision_fvar_interpolation_enum.insert("corners_plus1",
+                                             SUBDIVISION_FVAR_LINEAR_CORNERS_PLUS1);
+  subdivision_fvar_interpolation_enum.insert("corners_plus2",
+                                             SUBDIVISION_FVAR_LINEAR_CORNERS_PLUS2);
+  subdivision_fvar_interpolation_enum.insert("boundaries", SUBDIVISION_FVAR_LINEAR_BOUNDARIES);
+  subdivision_fvar_interpolation_enum.insert("all", SUBDIVISION_FVAR_LINEAR_ALL);
+  SOCKET_ENUM(subdivision_fvar_interpolation,
+              "Subdivision Face-Varying Interpolation",
+              subdivision_fvar_interpolation_enum,
+              SUBDIVISION_FVAR_LINEAR_BOUNDARIES);
+
+  SOCKET_INT_ARRAY(subd_vert_creases, "Subdivision Vertex Crease", array<int>());
+  SOCKET_FLOAT_ARRAY(
+      subd_vert_creases_weight, "Subdivision Vertex Crease Weights", array<float>());
+  SOCKET_INT_ARRAY(subd_creases_edge, "Subdivision Crease Edges", array<int>());
+  SOCKET_FLOAT_ARRAY(subd_creases_weight, "Subdivision Crease Weights", array<float>());
+  SOCKET_INT_ARRAY(subd_face_corners, "Subdivision Face Corners", array<int>());
+  SOCKET_INT_ARRAY(subd_start_corner, "Subdivision Face Start Corner", array<int>());
+  SOCKET_INT_ARRAY(subd_num_corners, "Subdivision Face Corner Count", array<int>());
+  SOCKET_INT_ARRAY(subd_shader, "Subdivision Face Shader", array<int>());
+  SOCKET_BOOLEAN_ARRAY(subd_smooth, "Subdivision Face Smooth", array<bool>());
+  SOCKET_INT_ARRAY(subd_ptex_offset, "Subdivision Face PTex Offset", array<int>());
+
+  /* Subdivisions parameters */
+  static NodeEnum subd_adaptive_space_enum;
+  subd_adaptive_space_enum.insert("pixel", SUBDIVISION_ADAPTIVE_SPACE_PIXEL);
+  subd_adaptive_space_enum.insert("object", SUBDIVISION_ADAPTIVE_SPACE_OBJECT);
+
+  SOCKET_ENUM(subd_adaptive_space,
+              "Subdivision Adaptive Space",
+              subd_adaptive_space_enum,
+              SUBDIVISION_ADAPTIVE_SPACE_PIXEL);
+  SOCKET_FLOAT(subd_dicing_rate, "Subdivision Dicing Rate", 1.0f)
+  SOCKET_INT(subd_max_level, "Max Subdivision Level", 1);
+  SOCKET_TRANSFORM(subd_objecttoworld, "Subdivision Object Transform", transform_identity());
+
+  return type;
+}
+
+bool Mesh::need_tesselation()
+{
+  return (subdivision_type != SUBDIVISION_NONE) &&
+         (position_is_modified() || subd_dicing_rate_is_modified() ||
+          subd_adaptive_space_is_modified() || subd_objecttoworld_is_modified() ||
+          subd_max_level_is_modified());
+}
+
+Mesh::Mesh(const NodeType *node_type, Type geom_type_)
+    : Geometry(node_type, geom_type_), subd_attributes(this, ATTR_PRIM_SUBD)
+{
+  face_offset = 0;
+  corner_offset = 0;
+
+  num_subd_added_verts = 0;
+  num_subd_faces = 0;
+
+  subdivision_type = SUBDIVISION_NONE;
+
+  add_builtin_attributes();
+}
+
+Mesh::Mesh() : Mesh(get_node_type(), Geometry::MESH) {}
+
+void Mesh::add_builtin_attributes()
+{
+  attributes.add(ATTR_STD_POSITION);
+}
+
+void Mesh::resize_mesh(const int numverts, const int numtris)
+{
+  Attribute *attr_P = attributes.add(ATTR_STD_POSITION);
+  attr_P->resize(numverts);
+  triangles.resize(numtris * 3);
+  shader.resize(numtris);
+  smooth.resize(numtris);
+
+  attributes.resize();
+}
+
+void Mesh::resize_subd_faces(const int numfaces, const int numcorners)
+{
+  subd_start_corner.resize(numfaces);
+  subd_num_corners.resize(numfaces);
+  subd_shader.resize(numfaces);
+  subd_smooth.resize(numfaces);
+  subd_ptex_offset.resize(numfaces);
+  subd_face_corners.resize(numcorners);
+  num_subd_faces = numfaces;
+
+  subd_attributes.resize();
+}
+
+void Mesh::reserve_subd_creases(const size_t num_creases)
+{
+  subd_creases_edge.reserve(num_creases * 2);
+  subd_creases_weight.reserve(num_creases);
+}
+
+void Mesh::clear_non_sockets()
+{
+  Geometry::clear(true);
+
+  num_subd_added_verts = 0;
+  num_subd_faces = 0;
+}
+
+void Mesh::clear(bool preserve_shaders, bool preserve_voxel_data)
+{
+  Geometry::clear(preserve_shaders);
+
+  /* clear all verts and triangles */
+  triangles.clear();
+  shader.clear();
+  smooth.clear();
+
+  subd_start_corner.clear();
+  subd_num_corners.clear();
+  subd_shader.clear();
+  subd_smooth.clear();
+  subd_ptex_offset.clear();
+  subd_face_corners.clear();
+
+  subd_creases_edge.clear();
+  subd_creases_weight.clear();
+
+  subd_attributes.clear();
+  attributes.clear(preserve_voxel_data);
+  add_builtin_attributes();
+
+  subdivision_type = SubdivisionType::SUBDIVISION_NONE;
+
+  clear_non_sockets();
+}
+
+void Mesh::clear(bool preserve_shaders)
+{
+  clear(preserve_shaders, false);
+}
+
+Mesh::SubdFace Mesh::get_subd_face(const size_t index) const
+{
+  Mesh::SubdFace s;
+  s.shader = subd_shader[index];
+  s.num_corners = subd_num_corners[index];
+  s.smooth = subd_smooth[index];
+  s.ptex_offset = subd_ptex_offset[index];
+  s.start_corner = subd_start_corner[index];
+  return s;
+}
+
+void Mesh::add_edge_crease(const int v0, const int v1, const float weight)
+{
+  subd_creases_edge.push_back_slow(v0);
+  subd_creases_edge.push_back_slow(v1);
+  subd_creases_weight.push_back_slow(weight);
+
+  tag_subd_creases_edge_modified();
+  tag_subd_creases_edge_modified();
+  tag_subd_creases_weight_modified();
+}
+
+void Mesh::add_vertex_crease(const int v, const float weight)
+{
+  subd_vert_creases.push_back_slow(v);
+  subd_vert_creases_weight.push_back_slow(weight);
+
+  tag_subd_vert_creases_modified();
+  tag_subd_vert_creases_weight_modified();
+}
+
+void Mesh::copy_center_to_motion_step(const int motion_step)
+{
+  const int attr_step = motion_step + 1;
+  for (AttributeSet *attr_set : {&attributes, &subd_attributes}) {
+    Attribute *attr_P = attr_set->find(ATTR_STD_POSITION);
+    if (attr_P && attr_P->has_motion()) {
+      const packed_float3 *P = attr_P->data<packed_float3>();
+      std::copy_n(P, attr_P->size, attr_P->data_for_write<packed_float3>(attr_step));
+    }
+
+    Attribute *attr_N = attr_set->find(ATTR_STD_VERTEX_NORMAL);
+    if (attr_N && attr_N->has_motion()) {
+      const packed_normal *N = attr_N->data<packed_normal>();
+      std::copy_n(N, attr_N->size, attr_N->data_for_write<packed_normal>(attr_step));
+    }
+  }
+
+  Attribute *attr_cN = attributes.find(ATTR_STD_CORNER_NORMAL);
+  if (attr_cN && attr_cN->has_motion()) {
+    const size_t numcorners = triangles.size();
+    const packed_normal *N = attr_cN->data<packed_normal>();
+    std::copy_n(N, numcorners, attr_cN->data_for_write<packed_normal>(attr_step));
+  }
+}
+
+void Mesh::get_uv_tiles(ustring map, unordered_set<int> &tiles)
+{
+  Attribute *attr;
+  Attribute *subd_attr;
+
+  if (map.empty()) {
+    attr = attributes.find(ATTR_STD_UV);
+    subd_attr = subd_attributes.find(ATTR_STD_UV);
+  }
+  else {
+    attr = attributes.find(map);
+    subd_attr = subd_attributes.find(map);
+  }
+
+  if (attr) {
+    attr->get_uv_tiles(this, ATTR_PRIM_GEOMETRY, tiles);
+  }
+  if (subd_attr) {
+    subd_attr->get_uv_tiles(this, ATTR_PRIM_SUBD, tiles);
+  }
+}
+
+void Mesh::compute_bounds()
+{
+  BoundBox bnds = BoundBox::empty;
+  const size_t verts_size = num_verts();
+  const packed_float3 *verts = get_position();
+
+  if (verts_size > 0) {
+    for (size_t i = 0; i < verts_size; i++) {
+      bnds.grow(verts[i]);
+    }
+
+    Attribute *attr_P = attributes.find(ATTR_STD_POSITION);
+    if (use_motion_blur && attr_P->has_motion()) {
+      for (int attr_step = 1; attr_step < attr_P->num_motion_steps(); attr_step++) {
+        const packed_float3 *vert_step = attr_P->data<packed_float3>(attr_step);
+        for (size_t i = 0; i < verts_size; i++) {
+          bnds.grow(vert_step[i]);
+        }
+      }
+    }
+
+    if (!bnds.valid()) {
+      bnds = BoundBox::empty;
+
+      /* skip nan or inf coordinates */
+      for (size_t i = 0; i < verts_size; i++) {
+        bnds.grow_safe(verts[i]);
+      }
+
+      if (use_motion_blur && attr_P->has_motion()) {
+        for (int attr_step = 1; attr_step < attr_P->num_motion_steps(); attr_step++) {
+          const packed_float3 *vert_step = attr_P->data<packed_float3>(attr_step);
+          for (size_t i = 0; i < verts_size; i++) {
+            bnds.grow_safe(vert_step[i]);
+          }
+        }
+      }
+    }
+  }
+
+  if (!bnds.valid()) {
+    /* empty mesh */
+    bnds.grow(zero_float3());
+  }
+
+  bounds = bnds;
+}
+
+void Mesh::apply_transform(const Transform &tfm, const bool apply_to_motion)
+{
+  transform_normal = transform_transposed_inverse(tfm);
+
+  /* apply to mesh vertices */
+  packed_float3 *verts = get_position_for_write();
+  const size_t num_verts = this->num_verts();
+  for (size_t i = 0; i < num_verts; i++) {
+    verts[i] = transform_point(&tfm, verts[i]);
+  }
+
+  tag_position_modified();
+
+  Attribute *attr_vN = attributes.find(ATTR_STD_VERTEX_NORMAL);
+  if (attr_vN) {
+    const Transform ntfm = transform_normal;
+    const size_t num_verts = this->num_verts();
+    packed_normal *vN = attr_vN->data_for_write<packed_normal>();
+
+    for (size_t i = 0; i < num_verts; i++) {
+      vN[i] = packed_normal(normalize(transform_direction(&ntfm, vN[i].decode())));
+    }
+  }
+
+  Attribute *attr_cN = attributes.find(ATTR_STD_CORNER_NORMAL);
+  if (attr_cN) {
+    const Transform ntfm = transform_normal;
+    const size_t num_corners = triangles.size();
+    packed_normal *cN = attr_cN->data_for_write<packed_normal>();
+
+    for (size_t i = 0; i < num_corners; i++) {
+      cN[i] = packed_normal(normalize(transform_direction(&ntfm, cN[i].decode())));
+    }
+  }
+
+  Attribute *attr_uN = attributes.find(ATTR_STD_NORMAL_UNDISPLACED);
+  if (attr_uN) {
+    const Transform ntfm = transform_normal;
+    const size_t size = attr_uN->buffer_size(this, ATTR_PRIM_GEOMETRY) / sizeof(packed_normal);
+    packed_normal *uN = attr_uN->data_for_write<packed_normal>();
+
+    for (size_t i = 0; i < size; i++) {
+      uN[i] = packed_normal(normalize(transform_direction(&ntfm, uN[i].decode())));
+    }
+  }
+
+  if (apply_to_motion) {
+    Attribute *attr_P = attributes.find(ATTR_STD_POSITION);
+
+    if (attr_P->has_motion()) {
+      const size_t num_verts = this->num_verts();
+      for (int step = 1; step <= int(attr_P->motion.size()); step++) {
+        packed_float3 *vert_step = attr_P->data_for_write<packed_float3>(step);
+        for (size_t i = 0; i < num_verts; i++) {
+          vert_step[i] = transform_point(&tfm, vert_step[i]);
+        }
+      }
+    }
+
+    Attribute *attr_mN = attributes.find(ATTR_STD_VERTEX_NORMAL);
+
+    if (attr_mN && attr_mN->has_motion()) {
+      const Transform ntfm = transform_normal;
+      const size_t num_verts = this->num_verts();
+      for (int step = 1; step <= int(attr_mN->motion.size()); step++) {
+        packed_normal *normal_step = attr_mN->data_for_write<packed_normal>(step);
+        for (size_t i = 0; i < num_verts; i++) {
+          normal_step[i] = packed_normal(
+              normalize(transform_direction(&ntfm, normal_step[i].decode())));
+        }
+      }
+    }
+
+    Attribute *attr_mcN = attributes.find(ATTR_STD_CORNER_NORMAL);
+
+    if (attr_mcN && attr_mcN->has_motion()) {
+      const Transform ntfm = transform_normal;
+      const size_t nc = triangles.size();
+      for (int step = 1; step <= int(attr_mcN->motion.size()); step++) {
+        packed_normal *normal_step = attr_mcN->data_for_write<packed_normal>(step);
+        for (size_t i = 0; i < nc; i++) {
+          normal_step[i] = packed_normal(
+              normalize(transform_direction(&ntfm, normal_step[i].decode())));
+        }
+      }
+    }
+  }
+}
+
+void Mesh::add_vertex_normals()
+{
+  Attribute *attr_cN = attributes.find(ATTR_STD_CORNER_NORMAL);
+  if (attr_cN) {
+    /* Not needed if we already have corner normals overriding these.
+     * If there is motion blur without motion corner normals we can't
+     * render correctly, discard corner normals. */
+    if (has_motion_blur() && !attr_cN->has_motion()) {
+      attributes.remove(ATTR_STD_CORNER_NORMAL);
+    }
+    else {
+      return;
+    }
+  }
+
+  const bool flip = transform_negative_scaled;
+  const size_t verts_size = num_verts();
+  const size_t triangles_size = num_triangles();
+
+  /* static vertex normals */
+  if (!attributes.find(ATTR_STD_VERTEX_NORMAL) && triangles_size) {
+    /* get attributes */
+    Attribute *attr_vN = attributes.add(ATTR_STD_VERTEX_NORMAL);
+
+    const packed_float3 *verts_ptr = get_position();
+    packed_normal *vN = attr_vN->data_for_write<packed_normal>();
+
+    /* compute vertex normals */
+    vector<float3> vN_float(verts_size, zero_float3());
+
+    for (size_t i = 0; i < triangles_size; i++) {
+      const float3 fN = get_triangle(i).compute_normal(verts_ptr);
+      for (size_t j = 0; j < 3; j++) {
+        vN_float[get_triangle(i).v[j]] += fN;
+      }
+    }
+
+    if (flip) {
+      for (size_t i = 0; i < verts_size; i++) {
+        vN[i] = packed_normal(-normalize(vN_float[i]));
+      }
+    }
+    else {
+      for (size_t i = 0; i < verts_size; i++) {
+        vN[i] = packed_normal(normalize(vN_float[i]));
+      }
+    }
+  }
+
+  /* motion vertex normals */
+  Attribute *attr_P = attributes.find(ATTR_STD_POSITION);
+  Attribute *attr_N = attributes.find(ATTR_STD_VERTEX_NORMAL);
+
+  if (has_motion_blur() && attr_P->has_motion() && !(attr_N && attr_N->has_motion()) &&
+      triangles_size)
+  {
+    if (!attr_N) {
+      attr_N = attributes.add(ATTR_STD_VERTEX_NORMAL);
+    }
+    attr_N->add_motion(this);
+
+    for (int attr_step = 1; attr_step < attr_P->num_motion_steps(); attr_step++) {
+      const packed_float3 *mP = attr_P->data<packed_float3>(attr_step);
+      packed_normal *mN = attr_N->data_for_write<packed_normal>(attr_step);
+
+      /* compute */
+      vector<float3> mN_float(verts_size, zero_float3());
+
+      for (size_t i = 0; i < triangles_size; i++) {
+        const Triangle tri = get_triangle(i);
+        const float3 fN = tri.compute_normal(mP);
+        for (size_t j = 0; j < 3; j++) {
+          mN_float[tri.v[j]] += fN;
+        }
+      }
+
+      if (flip) {
+        for (size_t i = 0; i < verts_size; i++) {
+          mN[i] = packed_normal(-normalize(mN_float[i]));
+        }
+      }
+      else {
+        for (size_t i = 0; i < verts_size; i++) {
+          mN[i] = packed_normal(normalize(mN_float[i]));
+        }
+      }
+    }
+  }
+
+  /* subd vertex normals */
+  if (!subd_attributes.find(ATTR_STD_VERTEX_NORMAL) && get_num_subd_faces()) {
+    /* get attributes */
+    Attribute *attr_vN = subd_attributes.add(ATTR_STD_VERTEX_NORMAL);
+    packed_normal *vN = attr_vN->data_for_write<packed_normal>();
+
+    /* compute vertex normals */
+    vector<float3> vN_float(verts_size, zero_float3());
+
+    for (size_t i = 0; i < get_num_subd_faces(); i++) {
+      const SubdFace face = get_subd_face(i);
+      const float3 fN = face.normal(this);
+
+      for (size_t j = 0; j < face.num_corners; j++) {
+        const size_t corner = subd_face_corners[face.start_corner + j];
+        vN_float[corner] += fN;
+      }
+    }
+
+    if (flip) {
+      for (size_t i = 0; i < verts_size; i++) {
+        vN[i] = packed_normal(-normalize(vN_float[i]));
+      }
+    }
+    else {
+      for (size_t i = 0; i < verts_size; i++) {
+        vN[i] = packed_normal(normalize(vN_float[i]));
+      }
+    }
+  }
+}
+
+void Mesh::add_undisplaced(Scene *scene)
+{
+  if (need_attribute(scene, ATTR_STD_POSITION_UNDISPLACED) &&
+      !attributes.find(ATTR_STD_POSITION_UNDISPLACED))
+  {
+    /* Copy position to attribute. */
+    Attribute *attr = attributes.add(ATTR_STD_POSITION_UNDISPLACED);
+
+    size_t size = attr->buffer_size(this, ATTR_PRIM_GEOMETRY) / sizeof(packed_float3);
+    std::copy_n(get_position(), size, attr->data_for_write<packed_float3>());
+  }
+
+  if (need_attribute(scene, ATTR_STD_NORMAL_UNDISPLACED) &&
+      !attributes.find(ATTR_STD_NORMAL_UNDISPLACED))
+  {
+    /* Copy corner or vertex normal to attribute, using the matching element type
+     * so the kernel reads and interpolates it correctly. */
+    Attribute *attr_N = attributes.find(ATTR_STD_CORNER_NORMAL);
+    if (!attr_N) {
+      attr_N = attributes.find(ATTR_STD_VERTEX_NORMAL);
+    }
+    if (attr_N) {
+      Attribute *attr = attributes.add(
+          ustring(Attribute::standard_name(ATTR_STD_NORMAL_UNDISPLACED)),
+          TypeNormal,
+          attr_N->element);
+      attr->std = ATTR_STD_NORMAL_UNDISPLACED;
+
+      size_t size = attr->buffer_size(this, ATTR_PRIM_GEOMETRY) / sizeof(packed_normal);
+      std::copy_n(attr_N->data<packed_normal>(), size, attr->data_for_write<packed_normal>());
+    }
+  }
+}
+
+void Mesh::update_generated(Scene *scene)
+{
+  if (!num_triangles() && !num_subd_faces) {
+    return;
+  }
+
+  AttributeSet &attrs = num_subd_faces ? subd_attributes : attributes;
+
+  /* apply generated attributes if needed or missing */
+  if (need_attribute(scene, ATTR_STD_GENERATED) && !attrs.find(ATTR_STD_GENERATED)) {
+    const Attribute *attr_P = attrs.find(ATTR_STD_POSITION);
+    if (attr_P) {
+      const size_t verts_size = attr_P->size;
+      const packed_float3 *verts = attr_P->data<packed_float3>();
+      Attribute *attr_generated = attrs.add(ATTR_STD_GENERATED);
+      packed_float3 *generated = attr_generated->data_for_write<packed_float3>();
+      for (size_t i = 0; i < verts_size; ++i) {
+        generated[i] = verts[i];
+      }
+    }
+  }
+}
+
+void Mesh::update_tangents(Scene *scene, bool undisplaced)
+{
+  if (!num_triangles()) {
+    return;
+  }
+
+  assert(attributes.find(ATTR_STD_VERTEX_NORMAL) || attributes.find(ATTR_STD_CORNER_NORMAL));
+
+  ccl::set<ustring> uv_maps;
+  Attribute *attr_std_uv = attributes.find(ATTR_STD_UV);
+
+  AttributeStandard tangent_std = (undisplaced) ? ATTR_STD_UV_TANGENT_UNDISPLACED :
+                                                  ATTR_STD_UV_TANGENT;
+  AttributeStandard tangent_sign_std = (undisplaced) ? ATTR_STD_UV_TANGENT_SIGN_UNDISPLACED :
+                                                       ATTR_STD_UV_TANGENT_SIGN;
+  const char *tangent_postfix = (undisplaced) ? ".undisplaced_tangent" : ".tangent";
+  const char *tangent_sign_postfix = (undisplaced) ? ".undisplaced_tangent_sign" : ".tangent_sign";
+
+  /* standard UVs */
+  if ((need_attribute(scene, tangent_std) || need_attribute(scene, tangent_sign_std)) &&
+      !attributes.find(tangent_std))
+  {
+    mikk_compute_tangents(attr_std_uv,
+                          this,
+                          true,
+                          tangent_std,
+                          tangent_sign_std,
+                          tangent_postfix,
+                          tangent_sign_postfix); /* sign */
+  }
+
+  /* now generate for any other UVs requested */
+  for (Attribute &attr : attributes.attributes) {
+    if (!(attr.type == TypeFloat2 && attr.element == ATTR_ELEMENT_CORNER)) {
+      continue;
+    }
+
+    const ustring tangent_name = ustring(attr.name.string() + tangent_postfix);
+    const ustring tangent_sign_name = ustring(attr.name.string() + tangent_sign_postfix);
+
+    if ((need_attribute(scene, tangent_name) || need_attribute(scene, tangent_sign_name)) &&
+        !attributes.find(tangent_name))
+    {
+      mikk_compute_tangents(&attr,
+                            this,
+                            true,
+                            tangent_std,
+                            tangent_sign_std,
+                            tangent_postfix,
+                            tangent_sign_postfix); /* sign */
+    }
+  }
+}
+
+void Mesh::pack_shaders(Scene *scene, uint *tri_shader)
+{
+  uint shader_id = 0;
+  uint last_shader = -1;
+  bool last_smooth = false;
+
+  const size_t triangles_size = num_triangles();
+  const int *shader_ptr = shader.data();
+
+  /* Corner normals override the smooth flag, as the flatness is already
+   * encoded in the corner normals and we always interpolate them. */
+  const bool use_corner_normals = attributes.find(ATTR_STD_CORNER_NORMAL) != nullptr;
+  const bool *smooth_ptr = (use_corner_normals) ? nullptr : smooth.data();
+  const bool smooth_constant = (use_corner_normals) ? true : false;
+
+  for (size_t i = 0; i < triangles_size; i++) {
+    const int new_shader = shader_ptr ? shader_ptr[i] : INT_MAX;
+    const bool new_smooth = smooth_ptr ? smooth_ptr[i] : smooth_constant;
+
+    if (new_shader != last_shader || last_smooth != new_smooth) {
+      last_shader = new_shader;
+      last_smooth = new_smooth;
+      Shader *shader = (last_shader < used_shaders.size()) ?
+                           static_cast<Shader *>(used_shaders[last_shader]) :
+                           scene->default_surface;
+      shader_id = scene->shader_manager->get_shader_id(shader, last_smooth);
+    }
+
+    tri_shader[i] = shader_id;
+  }
+}
+
+void Mesh::pack_triangles(packed_uint3 *tri_vindex)
+{
+  const size_t triangles_size = num_triangles();
+  const int *p_tris = triangles.data();
+  int off = 0;
+  for (size_t i = 0; i < triangles_size; i++) {
+    tri_vindex[i] = make_packed_uint3(p_tris[off + 0], p_tris[off + 1], p_tris[off + 2]);
+    off += 3;
+  }
+}
+
+bool Mesh::has_motion_blur() const
+{
+  Attribute *attr_P = attributes.find(ATTR_STD_POSITION);
+  Attribute *subd_attr_P = subd_attributes.find(ATTR_STD_POSITION);
+  return use_motion_blur &&
+         (attr_P->has_motion() || (get_subdivision_type() != Mesh::SUBDIVISION_NONE &&
+                                   subd_attr_P && subd_attr_P->has_motion()));
+}
+
+PrimitiveType Mesh::primitive_type() const
+{
+  return has_motion_blur() ? PRIMITIVE_MOTION_TRIANGLE : PRIMITIVE_TRIANGLE;
+}
+
+CCL_NAMESPACE_END