source/blender/render/hydra/engine.cc

@@ -87,7 +87,7 @@ void Engine::sync(Depsgraph *depsgraph, bContext *context)
       hydra_scene_delegate_ = std::make_unique<io::hydra::HydraSceneDelegate>(
           render_index_.get(), scene_path, scene_delegate_settings_);
     }
-    hydra_scene_delegate_->populate(depsgraph, CTX_wm_view3d(context));
+    hydra_scene_delegate_->populate(depsgraph, context ? CTX_wm_view3d(context) : nullptr);
   }
   else {
     /* Slow USD export for reference. */

source/blender/render/hydra/final_engine.cc

@@ -66,8 +66,6 @@ void FinalEngine::render(Depsgraph *depsgraph)
     }
   }
 
-  render_task_delegate_->bind();
-
   pxr::HdTaskSharedPtrVector tasks;
   if (light_tasks_delegate_) {
     if (scene->r.alphamode != R_ALPHAPREMUL) {
@@ -76,6 +74,9 @@ void FinalEngine::render(Depsgraph *depsgraph)
     tasks.push_back(light_tasks_delegate_->simple_task());
   }
   tasks.push_back(render_task_delegate_->task());
+
+  render_task_delegate_->bind();
+
   engine_->Execute(render_index_.get(), &tasks);
 
   char elapsed_time[32];

source/blender/render/hydra/render_task_delegate.cc

@@ -120,6 +120,7 @@ void RenderTaskDelegate::add_aov(pxr::TfToken const &aov_key)
   binding.aovName = aov_key;
   binding.renderBufferId = buf_id;
   binding.aovSettings = aov_desc.aovSettings;
+  binding.clearValue = pxr::VtValue(pxr::GfVec4f(0));
   task_params_.aovBindings.push_back(binding);
   render_index.GetChangeTracker().MarkTaskDirty(task_id_, pxr::HdChangeTracker::DirtyParams);
 
@@ -147,8 +148,11 @@ void RenderTaskDelegate::read_aov(pxr::TfToken const &aov_key, GPUTexture *textu
   if (!buffer) {
     return;
   }
+  eGPUDataFormat format = buffer->GetFormat() == pxr::HdFormat::HdFormatFloat16Vec4 ?
+                              GPU_DATA_HALF_FLOAT :
+                              GPU_DATA_FLOAT;
   void *buf_data = buffer->Map();
-  GPU_texture_update(texture, GPU_DATA_FLOAT, buf_data);
+  GPU_texture_update(texture, format, buf_data);
   buffer->Unmap();
 }
 
@@ -161,6 +165,17 @@ pxr::SdfPath RenderTaskDelegate::buffer_id(pxr::TfToken const &aov_key) const
   return GetDelegateID().AppendElementString("aov_" + aov_key.GetString());
 }
 
+GPURenderTaskDelegate::~GPURenderTaskDelegate()
+{
+  unbind();
+  if (tex_color_) {
+    GPU_texture_free(tex_color_);
+  }
+  if (tex_depth_) {
+    GPU_texture_free(tex_depth_);
+  }
+}
+
 void GPURenderTaskDelegate::set_viewport(pxr::GfVec4d const &viewport)
 {
   if (task_params_.viewport == viewport) {
@@ -270,22 +285,33 @@ void GPURenderTaskDelegate::bind()
 
   /* Workaround missing/buggy VAOs in hgiGL and hdSt. For OpenGL compatibility
    * profile this is not a problem, but for core profile it is. */
-  if (GPU_backend_get_type() == GPU_BACKEND_OPENGL) {
+  if (VAO_ == 0 && GPU_backend_get_type() == GPU_BACKEND_OPENGL) {
-    if (VAO_ == 0) {
     glGenVertexArrays(1, &VAO_);
-    }
     glBindVertexArray(VAO_);
   }
 }
 
 void GPURenderTaskDelegate::unbind()
 {
-  if (GPU_backend_get_type() == GPU_BACKEND_OPENGL) {
+  if (VAO_) {
     glDeleteVertexArrays(1, &VAO_);
+    VAO_ = 0;
   }
+  if (framebuffer_) {
     GPU_framebuffer_free(framebuffer_);
-  GPU_texture_free(tex_color_);
+    framebuffer_ = nullptr;
-  GPU_texture_free(tex_depth_);
+  }
+}
+
+GPUTexture *GPURenderTaskDelegate::aov_texture(pxr::TfToken const &aov_key)
+{
+  if (aov_key == pxr::HdAovTokens->color) {
+    return tex_color_;
+  }
+  if (aov_key == pxr::HdAovTokens->depth) {
+    return tex_depth_;
+  }
+  return nullptr;
 }
 
 }  // namespace blender::render::hydra

source/blender/render/hydra/render_task_delegate.h

@@ -52,6 +52,7 @@ class GPURenderTaskDelegate : public RenderTaskDelegate {
 
  public:
   using RenderTaskDelegate::RenderTaskDelegate;
+  ~GPURenderTaskDelegate() override;
 
   void set_viewport(pxr::GfVec4d const &viewport) override;
   void add_aov(pxr::TfToken const &aov_key) override;
@@ -59,6 +60,7 @@ class GPURenderTaskDelegate : public RenderTaskDelegate {
   void read_aov(pxr::TfToken const &aov_key, GPUTexture *texture) override;
   void bind() override;
   void unbind() override;
+  GPUTexture *aov_texture(pxr::TfToken const &aov_key);
 };
 
 }  // namespace blender::render::hydra

source/blender/render/hydra/viewport_engine.cc

@@ -183,18 +183,16 @@ void DrawTexture::write_data(int width, int height, const void *data)
                                    width,
                                    height,
                                    1,
-                                   GPU_RGBA16F,
+                                   GPU_RGBA32F,
                                    GPU_TEXTURE_USAGE_GENERAL,
                                    (float *)data);
 }
 
-void DrawTexture::draw(GPUShader *shader, const pxr::GfVec4d &viewport)
+void DrawTexture::draw(GPUShader *shader, const pxr::GfVec4d &viewport, GPUTexture *tex)
-{
-  draw(shader, texture_, viewport);
-}
-
-void DrawTexture::draw(GPUShader *shader, GPUTexture *tex, const pxr::GfVec4d &viewport)
 {
+  if (!tex) {
+    tex = texture_;
+  }
   int slot = GPU_shader_get_sampler_binding(shader, "image");
   GPU_texture_bind(tex, slot);
   GPU_shader_uniform_1i(shader, "image", slot);
@@ -237,20 +235,8 @@ void ViewportEngine::render(Depsgraph *depsgraph, bContext *context)
     light_tasks_delegate_->set_viewport(viewport);
   }
 
-  if ((bl_engine_->type->flag & RE_USE_GPU_CONTEXT) == 0) {
   render_task_delegate_->add_aov(pxr::HdAovTokens->color);
-  }
+  render_task_delegate_->add_aov(pxr::HdAovTokens->depth);
-
-  /* Workaround missing/buggy VAOs in hgiGL and hdSt. For OpenGL compatibility
-   * profile this is not a problem, but for core profile it is. */
-  GLuint VAO;
-  if (GPU_backend_get_type() == GPU_BACKEND_OPENGL) {
-    glGenVertexArrays(1, &VAO);
-    glBindVertexArray(VAO);
-  }
-
-  GPUShader *shader = GPU_shader_get_builtin_shader(GPU_SHADER_3D_IMAGE);
-  GPU_shader_bind(shader);
 
   pxr::HdTaskSharedPtrVector tasks;
   if (light_tasks_delegate_) {
@@ -260,9 +246,24 @@ void ViewportEngine::render(Depsgraph *depsgraph, bContext *context)
     tasks.push_back(light_tasks_delegate_->simple_task());
   }
   tasks.push_back(render_task_delegate_->task());
+
+  GPUFrameBuffer *view_framebuffer = GPU_framebuffer_active_get();
+  render_task_delegate_->bind();
+
   engine_->Execute(render_index_.get(), &tasks);
 
-  if ((bl_engine_->type->flag & RE_USE_GPU_CONTEXT) == 0) {
+  render_task_delegate_->unbind();
+
+  GPU_framebuffer_bind(view_framebuffer);
+  GPUShader *shader = GPU_shader_get_builtin_shader(GPU_SHADER_3D_IMAGE);
+  GPU_shader_bind(shader);
+
+  GPURenderTaskDelegate *gpu_task = dynamic_cast<GPURenderTaskDelegate *>(
+      render_task_delegate_.get());
+  if (gpu_task) {
+    draw_texture_.draw(shader, viewport, gpu_task->aov_texture(pxr::HdAovTokens->color));
+  }
+  else {
     draw_texture_.write_data(view_settings.width(), view_settings.height(), nullptr);
     render_task_delegate_->read_aov(pxr::HdAovTokens->color, draw_texture_.texture());
     draw_texture_.draw(shader, viewport);
@@ -270,10 +271,6 @@ void ViewportEngine::render(Depsgraph *depsgraph, bContext *context)
 
   GPU_shader_unbind();
 
-  if (GPU_backend_get_type() == GPU_BACKEND_OPENGL) {
-    glDeleteVertexArrays(1, &VAO);
-  }
-
   if (renderer_percent_done() == 0.0f) {
     time_begin_ = PIL_check_seconds_timer();
   }

source/blender/render/hydra/viewport_engine.h

@@ -23,8 +23,7 @@ class DrawTexture {
   ~DrawTexture();
 
   void write_data(int width, int height, const void *data);
-  void draw(GPUShader *shader, const pxr::GfVec4d &viewport);
+  void draw(GPUShader *shader, const pxr::GfVec4d &viewport, GPUTexture *tex = nullptr);
-  void draw(GPUShader *shader, GPUTexture *tex, const pxr::GfVec4d &viewport);
   GPUTexture *texture() const;
 
  private: