1 files changed, 95 insertions, 0 deletions
diff --git a/source/blender/io/usd/intern/usd_reader_mesh.h b/source/blender/io/usd/intern/usd_reader_mesh.h
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+++ b/source/blender/io/usd/intern/usd_reader_mesh.h
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+/*
+ * 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.
+ *
+ * Adapted from the Blender Alembic importer implementation.
+ *
+ * Modifications Copyright (C) 2021 Tangent Animation and
+ * NVIDIA Corporation.  All rights reserved.
+ */
+#pragma once
+
+#include "usd.h"
+#include "usd_reader_geom.h"
+
+#include "pxr/usd/usdGeom/mesh.h"
+
+struct MPoly;
+
+namespace blender::io::usd {
+
+class USDMeshReader : public USDGeomReader {
+ private:
+  pxr::UsdGeomMesh mesh_prim_;
+
+  std::unordered_map<std::string, pxr::TfToken> uv_token_map_;
+  std::map<const pxr::TfToken, bool> primvar_varying_map_;
+
+  /* TODO(makowalski): Is it the best strategy to cache the
+   * mesh geometry in the following members? It appears these
+   * arrays are never cleared, so this might bloat memory. */
+  pxr::VtIntArray face_indices_;
+  pxr::VtIntArray face_counts_;
+  pxr::VtVec3fArray positions_;
+  pxr::VtVec3fArray normals_;
+
+  pxr::TfToken normal_interpolation_;
+  pxr::TfToken orientation_;
+  bool is_left_handed_;
+  bool has_uvs_;
+  bool is_time_varying_;
+
+  /* This is to ensure we load all data once, because we reuse the read_mesh function
+   * in the mesh seq modifier, and in initial load. Ideally, a better fix would be
+   * implemented.  Note this will break if faces or positions vary. */
+  bool is_initial_load_;
+
+ public:
+  USDMeshReader(const pxr::UsdPrim &prim,
+                const USDImportParams &import_params,
+                const ImportSettings &settings);
+
+  bool valid() const override;
+
+  void create_object(Main *bmain, double motionSampleTime) override;
+  void read_object_data(Main *bmain, double motionSampleTime) override;
+
+  struct Mesh *read_mesh(struct Mesh *existing_mesh,
+                         double motionSampleTime,
+                         int read_flag,
+                         const char **err_str) override;
+
+  bool topology_changed(Mesh *existing_mesh, double motionSampleTime) override;
+
+ private:
+  void process_normals_vertex_varying(Mesh *mesh);
+  void process_normals_face_varying(Mesh *mesh);
+  void process_normals_uniform(Mesh *mesh);
+  void readFaceSetsSample(Main *bmain, Mesh *mesh, double motionSampleTime);
+  void assign_facesets_to_mpoly(double motionSampleTime,
+                                struct MPoly *mpoly,
+                                int totpoly,
+                                std::map<pxr::SdfPath, int> *r_mat_map);
+
+  void read_mpolys(Mesh *mesh);
+  void read_uvs(Mesh *mesh, double motionSampleTime, bool load_uvs = false);
+  void read_colors(Mesh *mesh, double motionSampleTime);
+
+  void read_mesh_sample(ImportSettings *settings,
+                        Mesh *mesh,
+                        double motionSampleTime,
+                        bool new_mesh);
+};
+
+}  // namespace blender::io::usd