doc/python_api/examples/bpy.types.HydraRenderEngine.py

@@ -7,6 +7,7 @@ USD Hydra Based Renderer
 
 import bpy
 
+
 class CustomHydraRenderEngine(bpy.types.HydraRenderEngine):
     # Identifier and name in the user interface.
     bl_idname = "CUSTOM_HYDRA_RENDERER"
@@ -53,8 +54,10 @@ class CustomHydraRenderEngine(bpy.types.HydraRenderEngine):
 def register():
     bpy.utils.register_class(CustomHydraRenderEngine)
 
+
 def unregister():
     bpy.utils.unregister_class(CustomHydraRenderEngine)
 
+
 if __name__ == "__main__":
     register()

scripts/modules/bpy_hydra.py

@@ -4,13 +4,10 @@ __all__ = (
     "export_mtlx",
 )
 
+
 def export_mtlx(material):
     """ Exports material to .mtlx file. It is called from Blender source code. """
-    try:
     import materialx.utils as mx_utils
-    except ImportError:
-        print("ERROR: no MaterialX addon available")
-        return ""
 
     doc = mx_utils.export(material, None)
     if not doc:

source/blender/io/usd/hydra/material.cc

@@ -113,9 +113,34 @@ pxr::HdCullStyle MaterialData::cull_style() const
 
 void MaterialData::export_mtlx()
 {
-  /* Call of python function hydra.export_mtlx() */
-
   PyGILState_STATE gstate;
+
+  /* Checking materialx addon */
+  static bool matx_addon_checked = false;
+  static bool has_matx_addon = false;
+
+  if (!matx_addon_checked) {
+    gstate = PyGILState_Ensure();
+    /* Adding second check into the lock, good practice to make this fully correct */
+    if (!matx_addon_checked) {
+      PyObject *mx_module = PyImport_ImportModule("materialx");
+      has_matx_addon = mx_module != nullptr;
+      Py_XDECREF(mx_module);
+
+      if (!has_matx_addon) {
+        PyErr_Print();
+        CLOG_WARN(LOG_HYDRA_SCENE, "No MaterialX addon, materials won't be exported.");
+      }
+      matx_addon_checked = true;
+    }
+    PyGILState_Release(gstate);
+  }
+
+  if (!has_matx_addon) {
+    return;
+  }
+
+  /* Call of python function bpy_hydra.export_mtlx() */
   gstate = PyGILState_Ensure();
 
   PyObject *module, *dict, *func, *result;

source/blender/render/hydra/CMakeLists.txt

@@ -62,6 +62,7 @@ set(INC_SYS
   ${BOOST_INCLUDE_DIR}
   ${TBB_INCLUDE_DIR}
   ${GFLAGS_INCLUDE_DIRS}
+  ${EIGEN3_INCLUDE_DIRS}
 )
 
 set(LIB

source/blender/render/hydra/engine.cc

@@ -55,7 +55,7 @@ Engine::Engine(RenderEngine *bl_engine, const std::string &render_delegate_name)
   free_camera_delegate_ = std::make_unique<pxr::HdxFreeCameraSceneDelegate>(
       render_index_.get(), pxr::SdfPath::AbsoluteRootPath().AppendElementString("freeCamera"));
 
-  if (bl_engine->type->flag & RE_USE_GPU_CONTEXT) {
+  if (bl_engine->type->flag & RE_USE_GPU_CONTEXT && GPU_backend_get_type() == GPU_BACKEND_OPENGL) {
     render_task_delegate_ = std::make_unique<GPURenderTaskDelegate>(
         render_index_.get(), pxr::SdfPath::AbsoluteRootPath().AppendElementString("renderTask"));
   }
@@ -133,4 +133,22 @@ float Engine::renderer_percent_done()
   return (float)it->second.UncheckedGet<double>();
 }
 
+pxr::HdTaskSharedPtrVector Engine::tasks()
+{
+  pxr::HdTaskSharedPtrVector res;
+  if (light_tasks_delegate_) {
+    if (scene_->r.alphamode != R_ALPHAPREMUL) {
+#ifndef __APPLE__
+      /* TODO: Temporary disable skydome task for MacOS due to crash with error:
+       * Failed to created pipeline state, error depthAttachmentPixelFormat is not valid
+       * and shader writes to depth */
+      res.push_back(light_tasks_delegate_->skydome_task());
+#endif
+    }
+    res.push_back(light_tasks_delegate_->simple_task());
+  }
+  res.push_back(render_task_delegate_->task());
+  return res;
+}
+
 }  // namespace blender::render::hydra

source/blender/render/hydra/engine.h

@@ -64,7 +64,10 @@ class Engine {
 
  protected:
   float renderer_percent_done();
-  virtual void notify_status(float progress, const std::string &title, const std::string &info) = 0;
+  pxr::HdTaskSharedPtrVector tasks();
+  virtual void notify_status(float progress,
+                             const std::string &title,
+                             const std::string &info) = 0;
 };
 
 }  // namespace blender::render::hydra

source/blender/render/hydra/final_engine.cc

@@ -66,18 +66,10 @@ void FinalEngine::render()
     render_task_delegate_->add_aov(pxr::HdAovTokens->depth);
   }
 
-  pxr::HdTaskSharedPtrVector tasks;
-  if (light_tasks_delegate_) {
-    if (scene_->r.alphamode != R_ALPHAPREMUL) {
-      tasks.push_back(light_tasks_delegate_->skydome_task());
-    }
-    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);
+  auto t = tasks();
+  engine_->Execute(render_index_.get(), &t);
 
   char elapsed_time[32];
   double time_begin = PIL_check_seconds_timer();

source/blender/render/hydra/python.cc

@@ -37,6 +37,7 @@ static PyObject *engine_create_func(PyObject * /*self*/, PyObject *args)
 
   RenderEngine *bl_engine = pyrna_to_pointer<RenderEngine>(pyengine, &RNA_RenderEngine);
 
+  CLOG_INFO(LOG_HYDRA_RENDER, 1, "Engine %s", engine_type);
   Engine *engine = nullptr;
   try {
     if (STREQ(engine_type, "VIEWPORT")) {
@@ -53,9 +54,7 @@ static PyObject *engine_create_func(PyObject * /*self*/, PyObject *args)
     CLOG_ERROR(LOG_HYDRA_RENDER, "%s", e.what());
   }
 
-  if (engine) {
-    CLOG_INFO(LOG_HYDRA_RENDER, 1, "Engine %p %s", engine, engine_type);
-  }
+  CLOG_INFO(LOG_HYDRA_RENDER, 1, "Engine %p", engine);
   return PyLong_FromVoidPtr(engine);
 }
 
@@ -67,9 +66,9 @@ static PyObject *engine_free_func(PyObject * /*self*/, PyObject *args)
   }
 
   Engine *engine = static_cast<Engine *>(PyLong_AsVoidPtr(pyengine));
+  CLOG_INFO(LOG_HYDRA_RENDER, 1, "Engine %p", engine);
   delete engine;
 
-  CLOG_INFO(LOG_HYDRA_RENDER, 1, "Engine %p", engine);
   Py_RETURN_NONE;
 }
 

source/blender/render/hydra/render_task_delegate.cc

@@ -13,8 +13,9 @@
 
 #include "MEM_guardedalloc.h"
 
+#include "Eigen/Core"
+
 #include "engine.h"
-#include "render_task_delegate.h"
 
 namespace blender::render::hydra {
 
@@ -107,6 +108,16 @@ void RenderTaskDelegate::add_aov(pxr::TfToken const &aov_key)
       aov_key);
 
   if (aov_desc.format == pxr::HdFormatInvalid) {
+    CLOG_ERROR(LOG_HYDRA_RENDER, "Invalid AOV: %s", aov_key.GetText());
+    return;
+  }
+  if (!ELEM(
+          pxr::HdGetComponentFormat(aov_desc.format), pxr::HdFormatFloat32, pxr::HdFormatFloat16))
+  {
+    CLOG_WARN(LOG_HYDRA_RENDER,
+              "Unsupported data format %s for AOV %s",
+              pxr::TfEnum::GetName(aov_desc.format).c_str(),
+              aov_key.GetText());
     return;
   }
 
@@ -120,7 +131,7 @@ 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));
+  binding.clearValue = aov_desc.clearValue;
   task_params_.aovBindings.push_back(binding);
   render_index.GetChangeTracker().MarkTaskDirty(task_id_, pxr::HdChangeTracker::DirtyParams);
 
@@ -134,12 +145,26 @@ void RenderTaskDelegate::read_aov(pxr::TfToken const &aov_key, void *data)
   if (!buffer) {
     return;
   }
+
+  pxr::HdFormat format = buffer->GetFormat();
+  size_t len = buffer->GetWidth() * buffer->GetHeight() * pxr::HdGetComponentCount(format);
+  if (pxr::HdGetComponentFormat(format) == pxr::HdFormatFloat32) {
     void *buf_data = buffer->Map();
-  memcpy(data,
-         buf_data,
-         buffer->GetWidth() * buffer->GetHeight() * pxr::HdDataSizeOfFormat(buffer->GetFormat()));
+    memcpy(data, buf_data, len * sizeof(float));
     buffer->Unmap();
   }
+  else if (pxr::HdGetComponentFormat(format) == pxr::HdFormatFloat16) {
+    Eigen::half *buf_data = (Eigen::half *)buffer->Map();
+    float *fdata = (float *)data;
+    for (size_t i = 0; i < len; ++i) {
+      fdata[i] = buf_data[i];
+    }
+    buffer->Unmap();
+  }
+  else {
+    BLI_assert_unreachable();
+  }
+}
 
 void RenderTaskDelegate::read_aov(pxr::TfToken const &aov_key, GPUTexture *texture)
 {
@@ -210,6 +235,7 @@ void GPURenderTaskDelegate::add_aov(pxr::TfToken const &aov_key)
     tex = &tex_depth_;
   }
   else {
+    CLOG_ERROR(LOG_HYDRA_RENDER, "Invalid AOV: %s", aov_key.GetText());
     return;
   }
 
@@ -253,14 +279,11 @@ void GPURenderTaskDelegate::read_aov(pxr::TfToken const &aov_key, void *data)
 void GPURenderTaskDelegate::read_aov(pxr::TfToken const &aov_key, GPUTexture *texture)
 {
   GPUTexture *tex = nullptr;
-  int c;
   if (aov_key == pxr::HdAovTokens->color) {
     tex = tex_color_;
-    c = 4;
   }
   else if (aov_key == pxr::HdAovTokens->depth) {
     tex = tex_depth_;
-    c = 1;
   }
   if (!tex) {
     return;

source/blender/render/hydra/viewport_engine.cc

@@ -232,19 +232,11 @@ void ViewportEngine::render()
   render_task_delegate_->add_aov(pxr::HdAovTokens->color);
   render_task_delegate_->add_aov(pxr::HdAovTokens->depth);
 
-  pxr::HdTaskSharedPtrVector tasks;
-  if (light_tasks_delegate_) {
-    if (scene_->r.alphamode != R_ALPHAPREMUL) {
-      tasks.push_back(light_tasks_delegate_->skydome_task());
-    }
-    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);
+  auto t = tasks();
+  engine_->Execute(render_index_.get(), &t);
 
   render_task_delegate_->unbind();
 
@@ -293,7 +285,8 @@ void ViewportEngine::render(bContext *context)
   render();
 }
 
-void ViewportEngine::notify_status(float /*progress*/, const std::string &info,
+void ViewportEngine::notify_status(float /*progress*/,
+                                   const std::string &info,
                                    const std::string &status)
 {
   RE_engine_update_stats(bl_engine_, status.c_str(), info.c_str());