source/blender/render/hydra/engine.cc

@@ -43,6 +43,8 @@ Engine::Engine(RenderEngine *bl_engine, const std::string &render_delegate_name)
   render_index_.reset(pxr::HdRenderIndex::New(render_delegate_.Get(), hd_drivers));
   free_camera_delegate_ = std::make_unique<pxr::HdxFreeCameraSceneDelegate>(
       render_index_.get(), pxr::SdfPath::AbsoluteRootPath().AppendElementString("freeCamera"));
+  scene_delegate_ = std::make_unique<BlenderSceneDelegate>(
+      render_index_.get(), pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"), this);
   render_task_delegate_ = std::make_unique<RenderTaskDelegate>(
       render_index_.get(), pxr::SdfPath::AbsoluteRootPath().AppendElementString("renderTask"));
   if (render_delegate_name == "HdStormRendererPlugin") {
@@ -56,7 +58,7 @@ Engine::Engine(RenderEngine *bl_engine, const std::string &render_delegate_name)
 
 void Engine::set_sync_setting(const pxr::TfToken &key, const pxr::VtValue &val)
 {
-  settings[key] = val;
+  scene_delegate_->set_setting(key, val);
 }
 
 void Engine::set_render_setting(const pxr::TfToken &key, const pxr::VtValue &val)

source/blender/render/hydra/engine.h

@@ -25,8 +25,6 @@ extern struct CLG_LogRef *LOG_RENDER_HYDRA;
 
 class Engine {
  public:
-  enum class EngineType { VIEWPORT = 1, FINAL, PREVIEW };
-
   Engine(RenderEngine *bl_engine, const std::string &render_delegate_name);
   virtual ~Engine() = default;
 
@@ -36,9 +34,7 @@ class Engine {
   void set_sync_setting(const pxr::TfToken &key, const pxr::VtValue &val);
   void set_render_setting(const pxr::TfToken &key, const pxr::VtValue &val);
 
-  EngineType type;
   std::string render_delegate_name;
-  pxr::TfHashMap<pxr::TfToken, pxr::VtValue, pxr::TfToken::HashFunctor> settings;
 
  protected:
   float renderer_percent_done();

source/blender/render/hydra/final_engine.cc

@@ -13,16 +13,8 @@
 
 namespace blender::render::hydra {
 
-FinalEngine::FinalEngine(RenderEngine *bl_engine, const std::string &render_delegate_name)
-    : Engine(bl_engine, render_delegate_name)
-{
-  type = EngineType::FINAL;
-}
-
 void FinalEngine::sync(Depsgraph *depsgraph, bContext *context)
 {
-  scene_delegate_ = std::make_unique<BlenderSceneDelegate>(
-      render_index_.get(), pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"), this);
   scene_delegate_->populate(depsgraph, context);
 }
 

source/blender/render/hydra/final_engine.h

@@ -9,7 +9,7 @@ namespace blender::render::hydra {
 
 class FinalEngine : public Engine {
  public:
-  FinalEngine(RenderEngine *bl_engine, const std::string &render_delegate_name);
+  using Engine::Engine;
 
   virtual void sync(Depsgraph *depsgraph, bContext *context) override;
   virtual void render(Depsgraph *b_depsgraph) override;

source/blender/render/hydra/preview_engine.cc

@@ -13,12 +13,6 @@ const double LIFETIME = 180.0;
 
 std::unique_ptr<PreviewEngine> PreviewEngine::instance_;
 
-PreviewEngine::PreviewEngine(RenderEngine *bl_engine, const std::string &render_delegate_name)
-    : FinalEngine(bl_engine, render_delegate_name)
-{
-  type = EngineType::PREVIEW;
-}
-
 PreviewEngine *PreviewEngine::get_instance(RenderEngine *bl_engine,
                                            const std::string &render_delegate_name)
 {
@@ -44,10 +38,6 @@ void PreviewEngine::schedule_free()
 
 void PreviewEngine::sync(Depsgraph *depsgraph, bContext *context)
 {
-  if (!scene_delegate_) {
-    scene_delegate_ = std::make_unique<BlenderSceneDelegate>(
-        render_index_.get(), pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"), this);
-  }
   scene_delegate_->clear();
   scene_delegate_->populate(depsgraph, context);
 }

source/blender/render/hydra/preview_engine.h

@@ -9,8 +9,7 @@ namespace blender::render::hydra {
 
 class PreviewEngine : public FinalEngine {
  public:
-  PreviewEngine(RenderEngine *bl_engine, const std::string &render_delegate_name);
+  using FinalEngine::FinalEngine;
-
   static PreviewEngine *get_instance(RenderEngine *bl_engine,
                                      const std::string &render_delegate_name);
   static void schedule_free();
@@ -19,12 +18,13 @@ class PreviewEngine : public FinalEngine {
   void render(Depsgraph *depsgraph) override;
 
  private:
-  /* Singleton class instance */
   static double free_instance(uintptr_t uuid, void *user_data);
-  static std::unique_ptr<PreviewEngine> instance_;
 
   void update(RenderEngine *bl_engine, const std::string &render_delegate_name);
   void update_render_result(std::vector<float> &pixels);
+
+  /* Singleton class instance */
+  static std::unique_ptr<PreviewEngine> instance_;
 };
 
 }  // namespace blender::render::hydra

source/blender/render/hydra/python.cc

@@ -216,7 +216,7 @@ static pxr::VtValue get_setting_val(PyObject *pyval)
     val = PyFloat_AsDouble(pyval);
   }
   else if (PyUnicode_Check(pyval)) {
-    val = PyUnicode_AsUTF8(pyval);
+    val = std::string(PyUnicode_AsUTF8(pyval));
   }
   return val;
 }

source/blender/render/hydra/scene_delegate/blender_scene_delegate.cc

@@ -203,6 +203,13 @@ void BlenderSceneDelegate::clear()
   view3d = nullptr;
 }
 
+void BlenderSceneDelegate::set_setting(const pxr::TfToken &key, const pxr::VtValue &val)
+{
+  if (key.GetString() == "MaterialXFilenameKey") {
+    settings.mx_filename_key = pxr::TfToken(val.Get<std::string>());
+  }
+}
+
 pxr::SdfPath BlenderSceneDelegate::prim_id(ID *id, const char *prefix) const
 {
   /* Making id of object in form like <prefix>_<pointer in 16 hex digits format> */

source/blender/render/hydra/scene_delegate/blender_scene_delegate.h

@@ -29,6 +29,10 @@ class BlenderSceneDelegate : public pxr::HdSceneDelegate {
   friend MaterialData; /* has access to objects and instancers */
 
  public:
+  struct Settings {
+    pxr::TfToken mx_filename_key;
+  };
+
   BlenderSceneDelegate(pxr::HdRenderIndex *parent_index,
                        pxr::SdfPath const &delegate_id,
                        Engine *engine);
@@ -54,12 +58,14 @@ class BlenderSceneDelegate : public pxr::HdSceneDelegate {
 
   void populate(Depsgraph *depsgraph, bContext *context);
   void clear();
+  void set_setting(const pxr::TfToken &key, const pxr::VtValue &val);
 
   Depsgraph *depsgraph = nullptr;
   bContext *context = nullptr;
   View3D *view3d = nullptr;
   Scene *scene = nullptr;
   Engine *engine;
+  Settings settings;
 
  private:
   pxr::SdfPath prim_id(ID *id, const char *prefix) const;

source/blender/render/hydra/scene_delegate/material.cc

@@ -14,6 +14,7 @@
 #include "RNA_blender_cpp.h"
 #include "bpy_rna.h"
 
+#include "../engine.h"
 #include "blender_scene_delegate.h"
 #include "material.h"
 #include "mtlx_hydra_adapter.h"
@@ -31,8 +32,65 @@ void MaterialData::init()
 {
   ID_LOG(2, "");
   double_sided = (((Material *)id)->blend_flag & MA_BL_CULL_BACKFACE) == 0;
-  material_network_map_ = pxr::VtValue();
 
+  export_mtlx();
+  if (!scene_delegate_->settings.mx_filename_key.IsEmpty()) {
+    write_material_network_map();
+  }
+}
+
+void MaterialData::insert()
+{
+  ID_LOG(2, "");
+  scene_delegate_->GetRenderIndex().InsertSprim(
+      pxr::HdPrimTypeTokens->material, scene_delegate_, prim_id);
+}
+
+void MaterialData::remove()
+{
+  CLOG_INFO(LOG_RENDER_HYDRA_SCENE, 2, "%s", prim_id.GetText());
+  scene_delegate_->GetRenderIndex().RemoveSprim(pxr::HdPrimTypeTokens->material, prim_id);
+}
+
+void MaterialData::update()
+{
+  ID_LOG(2, "");
+  bool prev_double_sided = double_sided;
+  init();
+  scene_delegate_->GetRenderIndex().GetChangeTracker().MarkSprimDirty(prim_id,
+                                                                      pxr::HdMaterial::AllDirty);
+  if (prev_double_sided != double_sided) {
+    for (auto &it : scene_delegate_->objects_) {
+      MeshData *m_data = dynamic_cast<MeshData *>(it.second.get());
+      if (m_data) {
+        m_data->update_double_sided(this);
+      }
+    }
+    for (auto &it : scene_delegate_->instancers_) {
+      it.second->update_double_sided(this);
+    }
+  }
+}
+
+pxr::VtValue MaterialData::get_data(pxr::TfToken const &key) const
+{
+  pxr::VtValue ret;
+  if (key.GetString() == "MaterialXFilename") {
+    if (!mtlx_path_.GetResolvedPath().empty()) {
+      ret = mtlx_path_;
+    }
+    ID_LOG(3, "%s", key.GetText());
+  }
+  return ret;
+}
+
+pxr::VtValue MaterialData::get_material_resource() const
+{
+  return material_network_map_;
+}
+
+void MaterialData::export_mtlx()
+{
   /* Call of python function hydra.export_mtlx() */
 
   PyGILState_STATE gstate;
@@ -87,71 +145,25 @@ void MaterialData::init()
 
   mtlx_path_ = pxr::SdfAssetPath(path, path);
   ID_LOG(2, "mtlx=%s", mtlx_path_.GetResolvedPath().c_str());
+}
+
+void MaterialData::write_material_network_map()
+{
+  ID_LOG(2, "");
+  if (mtlx_path_.GetResolvedPath().empty()) {
+    material_network_map_ = pxr::VtValue();
+    return;
+  }
 
-  /* Calculate material network map */
-  if (!path.empty()) {
   pxr::HdRenderDelegate *render_delegate = scene_delegate_->GetRenderIndex().GetRenderDelegate();
   pxr::TfTokenVector shader_source_types = render_delegate->GetShaderSourceTypes();
   pxr::TfTokenVector render_contexts = render_delegate->GetMaterialRenderContexts();
 
   pxr::HdMaterialNetworkMap network_map;
-    hdmtlx_convert_to_materialnetworkmap(path, shader_source_types, render_contexts, &network_map);
+  hdmtlx_convert_to_materialnetworkmap(
+      mtlx_path_.GetResolvedPath(), shader_source_types, render_contexts, &network_map);
 
   material_network_map_ = network_map;
-  }
-  else {
-    material_network_map_ = pxr::VtValue();
-  }
-}
-
-void MaterialData::insert()
-{
-  ID_LOG(2, "");
-  scene_delegate_->GetRenderIndex().InsertSprim(
-      pxr::HdPrimTypeTokens->material, scene_delegate_, prim_id);
-}
-
-void MaterialData::remove()
-{
-  CLOG_INFO(LOG_RENDER_HYDRA_SCENE, 2, "%s", prim_id.GetText());
-  scene_delegate_->GetRenderIndex().RemoveSprim(pxr::HdPrimTypeTokens->material, prim_id);
-}
-
-void MaterialData::update()
-{
-  ID_LOG(2, "");
-  bool prev_double_sided = double_sided;
-  init();
-  scene_delegate_->GetRenderIndex().GetChangeTracker().MarkSprimDirty(prim_id,
-                                                                      pxr::HdMaterial::AllDirty);
-  if (prev_double_sided != double_sided) {
-    for (auto &it : scene_delegate_->objects_) {
-      MeshData *m_data = dynamic_cast<MeshData *>(it.second.get());
-      if (m_data) {
-        m_data->update_double_sided(this);
-      }
-    }
-    for (auto &it : scene_delegate_->instancers_) {
-      it.second->update_double_sided(this);
-    }
-  }
-}
-
-pxr::VtValue MaterialData::get_data(pxr::TfToken const &key) const
-{
-  pxr::VtValue ret;
-  if (key.GetString() == "MaterialXFilename") {
-    if (!mtlx_path_.GetResolvedPath().empty()) {
-      ret = mtlx_path_;
-    }
-    ID_LOG(3, "%s", key.GetText());
-  }
-  return ret;
-}
-
-pxr::VtValue MaterialData::get_material_resource() const
-{
-  return material_network_map_;
 }
 
 }  // namespace blender::render::hydra

source/blender/render/hydra/scene_delegate/material.h

@@ -30,6 +30,9 @@ class MaterialData : public IdData {
   bool double_sided = true;
 
  private:
+  void export_mtlx();
+  void write_material_network_map();
+
   pxr::SdfAssetPath mtlx_path_;
   pxr::VtValue material_network_map_;
 };

source/blender/render/hydra/viewport_engine.cc

@@ -217,18 +217,8 @@ void DrawTexture::free()
   texture_ = nullptr;
 }
 
-ViewportEngine::ViewportEngine(RenderEngine *bl_engine, const std::string &render_delegate_name)
-    : Engine(bl_engine, render_delegate_name)
-{
-  type = EngineType::VIEWPORT;
-}
-
 void ViewportEngine::sync(Depsgraph *depsgraph, bContext *context)
 {
-  if (!scene_delegate_) {
-    scene_delegate_ = std::make_unique<BlenderSceneDelegate>(
-        render_index_.get(), pxr::SdfPath::AbsoluteRootPath().AppendElementString("scene"), this);
-  }
   scene_delegate_->populate(depsgraph, context);
 }
 

source/blender/render/hydra/viewport_engine.h

@@ -32,7 +32,7 @@ class DrawTexture {
 
 class ViewportEngine : public Engine {
  public:
-  ViewportEngine(RenderEngine *bl_engine, const std::string &render_delegate_name);
+  using Engine::Engine;
 
   void sync(Depsgraph *depsgraph, bContext *context) override;
   void render(Depsgraph *depsgraph) override;