usd_reader_prim.hh

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/* SPDX-FileCopyrightText: 2021 Tangent Animation. All rights reserved.
 * SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * Adapted from the Blender Alembic importer implementation. */
 
#pragma once
 
#include "usd.hh"
#include "usd_hash_types.hh"
 
#include "BLI_map.hh"
#include "BLI_set.hh"
 
#include "WM_types.hh"
 
#include <pxr/usd/sdf/path.h>
#include <pxr/usd/usd/prim.h>
 
#include <string>
 
struct CacheFile;
struct Main;
struct Material;
struct Object;
struct ReportList;
 
namespace blender::io::usd {
 
struct ImportSettings {
  bool blender_stage_version_prior_44 = false;
  bool do_convert_mat = false;
  float conversion_mat[4][4] = {};
 
  /* From MeshSeqCacheModifierData.read_flag */
  int read_flag = 0;
 
  std::function<CacheFile *()> get_cache_file{};
 
  /*
   * The fields below are mutable because they are used to keep track
   * of what the importer is doing. This is necessary even when all
   * the other import settings are to remain const.
   */
 
  /* Map a USD material prim path to a Blender material.
   * This map is updated by readers during stage traversal. */
  mutable blender::Map<pxr::SdfPath, Material *> usd_path_to_mat{};
  /* Map a material name to Blender material.
   * This map is updated by readers during stage traversal. */
  mutable blender::Map<std::string, Material *> mat_name_to_mat{};
  /* Map a USD material prim path to a Blender material to be
   * converted by invoking the 'on_material_import' USD hook.
   * This map is updated by readers during stage traversal. */
  mutable blender::Map<pxr::SdfPath, Material *> usd_path_to_mat_for_hook{};
  /* Set of paths to USD material primitives that can be converted by the
   * 'on_material_import' USD hook. For efficiency this set should
   * be populated prior to stage traversal. */
  mutable blender::Set<pxr::SdfPath> mat_import_hook_sources{};
 
  /* We use the stage metersPerUnit to convert camera properties from USD scene units to the
   * correct millimeter scale that Blender uses for camera parameters. */
  double stage_meters_per_unit = 1.0;
 
  pxr::SdfPath skip_prefix{};
 
  /* Combined user-specified and unit conversion scales. */
  double scene_scale = 1.0;
};
 
/* Most generic USD Reader. */
 
class USDPrimReader {
 
 protected:
  StringRefNull name_;
  Object *object_;
  pxr::UsdPrim prim_;
  USDPrimReader *parent_reader_;
  const USDImportParams &import_params_;
  const ImportSettings *settings_;
  int refcount_;
  bool is_in_instancer_proto_;
 
 public:
  USDPrimReader(const pxr::UsdPrim &prim,
                const USDImportParams &import_params,
                const ImportSettings &settings);
  virtual ~USDPrimReader();
 
  const pxr::UsdPrim &prim() const;
 
  virtual bool valid() const;
 
  virtual void create_object(Main *bmain) = 0;
  virtual void read_object_data(Main * /*bmain*/, pxr::UsdTimeCode /*time*/) {};
 
  Object *object() const;
  void object(Object *ob);
 
  USDPrimReader *parent() const
  {
    return parent_reader_;
  }
  void parent(USDPrimReader *parent)
  {
    parent_reader_ = parent;
  }

  ReportList *reports() const
  {
    return import_params_.worker_status ? import_params_.worker_status->reports : nullptr;
  }
 
  /* Since readers might be referenced through handles
   * maintained by modifiers and constraints, we provide
   * a reference count to facilitate managing the object
   * lifetime.
   * TODO(makowalski): investigate transitioning to using
   * smart pointers for readers, or, alternatively look into
   * making the lifetime management more robust, e.g., by
   * making the destructors protected and implementing deletion
   * in decref(), etc. */
  int refcount() const;
  void incref();
  void decref();
 
  StringRefNull name() const
  {
    return name_;
  }
  pxr::SdfPath prim_path() const
  {
    return prim_.GetPrimPath();
  }
 
  virtual pxr::SdfPath object_prim_path() const
  {
    return prim_path();
  }
 
  virtual pxr::SdfPath data_prim_path() const
  {
    return prim_path();
  }
 
  void set_is_in_instancer_proto(bool flag)
  {
    is_in_instancer_proto_ = flag;
  }
 
  bool is_in_instancer_proto() const
  {
    return is_in_instancer_proto_;
  }
 
  bool is_in_proto() const;
 
 protected:
  void set_props(bool merge_with_parent = false,
                 pxr::UsdTimeCode time = pxr::UsdTimeCode::Default());
};
 
}  // namespace blender::io::usd