scripts/modules/bpy_hydra.py

@@ -63,7 +63,6 @@ class HydraRenderEngine(bpy.types.RenderEngine):
             return
 
         _bpy_hydra.engine_free(self.engine_ptr)
-        del self.engine_ptr
 
     @classmethod
     def register(cls):
@@ -95,6 +94,8 @@ class HydraRenderEngine(bpy.types.RenderEngine):
     def update(self, data, depsgraph):
         engine_type = 'PREVIEW' if self.is_preview else 'FINAL'
         self.engine_ptr = _bpy_hydra.engine_create(self.as_pointer(), engine_type, self.delegate_id)
+        if not self.engine_ptr:
+            return
 
         for key, val in self.get_sync_settings(engine_type).items():
             _bpy_hydra.engine_set_sync_setting(self.engine_ptr, key, val)
@@ -114,6 +115,8 @@ class HydraRenderEngine(bpy.types.RenderEngine):
     def view_update(self, context, depsgraph):
         if not self.engine_ptr:
             self.engine_ptr = _bpy_hydra.engine_create(self.as_pointer(), 'VIEWPORT', self.delegate_id)
+        if not self.engine_ptr:
+            return
 
         for key, val in self.get_sync_settings('VIEWPORT').items():
             _bpy_hydra.engine_set_sync_setting(self.engine_ptr, key, val)

source/blender/render/hydra/engine.cc

@@ -23,7 +23,6 @@ Engine::Engine(RenderEngine *bl_engine, const std::string &render_delegate_name)
   pxr::HdRendererPluginRegistry &registry = pxr::HdRendererPluginRegistry::GetInstance();
 
   pxr::TF_PY_ALLOW_THREADS_IN_SCOPE();
-  render_delegate_ = registry.CreateRenderDelegate(pxr::TfToken(render_delegate_name));
 
   /* USD has limited support for Vulkan. To make it works USD should be built
    * with PXR_ENABLE_VULKAN_SUPPORT=TRUE which is not possible now */
@@ -39,6 +38,11 @@ Engine::Engine(RenderEngine *bl_engine, const std::string &render_delegate_name)
 
     hd_drivers.push_back(&hgi_driver_);
   }
+  render_delegate_ = registry.CreateRenderDelegate(pxr::TfToken(render_delegate_name));
+
+  if (!render_delegate_) {
+    throw std::runtime_error("Cannot create render delegate: " + render_delegate_name);
+  }
 
   render_index_.reset(pxr::HdRenderIndex::New(render_delegate_.Get(), hd_drivers));
   free_camera_delegate_ = std::make_unique<pxr::HdxFreeCameraSceneDelegate>(

source/blender/render/hydra/python.cc

@@ -65,7 +65,8 @@ static PyObject *engine_create_func(PyObject * /*self*/, PyObject *args)
 
   RenderEngine *bl_engine = (RenderEngine *)PyLong_AsVoidPtr(pyengine);
 
-  Engine *engine;
+  Engine *engine = nullptr;
+  try {
     if (STREQ(engine_type, "VIEWPORT")) {
       engine = new ViewportEngine(bl_engine, render_delegate_id);
     }
@@ -80,8 +81,14 @@ static PyObject *engine_create_func(PyObject * /*self*/, PyObject *args)
         engine = new FinalEngine(bl_engine, render_delegate_id);
       }
     }
+  }
+  catch (std::runtime_error &e) {
+    CLOG_ERROR(LOG_RENDER_HYDRA, "%s", e.what());
+  }
 
+  if (engine) {
     CLOG_INFO(LOG_RENDER_HYDRA, 1, "Engine %016llx %s", engine, engine_type);
+  }
   return PyLong_FromVoidPtr(engine);
 }