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

@@ -0,0 +1,54 @@
+"""
+Base class for integrating USD Hydra based renderers.
+
+USD Hydra Based Renderer
+++++++++++++++++++++++++
+"""
+
+import bpy
+
+class CustomHydraRenderEngine(bpy.types.HydraRenderEngine):
+    # Identifier and name in the user interface.
+    bl_idname = "CUSTOM_HYDRA_RENDERER"
+    bl_label = "Custom Hydra Renderer"
+
+    # Name of the render plugin.
+    bl_delegate_id = "HdCustomRendererPlugin"
+
+    # Register path to plugin.
+    @classmethod
+    def register(cls):
+        super().register()
+
+        import pxr
+        pxr.Plug.Registry().RegisterPlugins(['/path/to/plugin'])
+
+    # Render settings that will be passed to the delegate.
+    def get_render_settings(self, engine_type):
+        return {
+            'myBoolean': True,
+            'myValue': 8,
+        }
+
+    # Settings used by the synchronization process.
+    def get_sync_settings(self, engine_type):
+        return {
+            'MaterialXFilenameKey': "MaterialXFilename",
+        }
+
+    # RenderEngine methods for update, render and draw are implemented in
+    # HydraRenderEngine. Optionally extra work can be done before or after
+    # by implementing the methods like this.
+    def update(self, data, depsgraph):
+        super().update(data, depsgraph)
+        # Do extra work here
+
+# Registration
+def register():
+    bpy.utils.register_class(CustomHydraRenderEngine)
+
+def unregister():
+    bpy.utils.unregister_class(CustomHydraRenderEngine)
+
+if __name__ == "__main__":
+    register()

scripts/modules/bpy_hydra.py

@@ -1,147 +1,9 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 
-"""
-Implementation of class `HydraRenderEngine`.
-
-Render Blender addon with Hydra render delegate should inherit `HydraRenderEngine`.
-Example:
-```
-import bpy_hydra
-
-class CustomHydraRenderEngine(HydraRenderEngine):
-    bl_idname = 'CustomHydraRenderEngine'
-    bl_label = "Hydra: Custom"
-    bl_info = "Hydra Custom render delegate"
-
-    delegate_id = 'HdCustomRendererPlugin'
-
-    @classmethod
-    def register(cls):
-        super().register()
-
-        bpy_hydra.register_plugins(["/path/to/plugin")])
-
-    def get_sync_settings(self, engine_type):
-        return {
-            'MaterialXFilenameKey': "MaterialXFilename",
-        }
-
-    def get_render_settings(self, engine_type):
-        return {
-            'enableTinyPrimCulling': True,
-            'maxLights': 8,
-        }
-```
-"""
-
 __all__ = (
-    "HydraRenderEngine",
     "export_mtlx",
-    "register_plugins",
 )
 
-import os
-import platform
-from pathlib import Path
-
-import bpy
-import _bpy_hydra
-
-from _bpy_hydra import register_plugins
-
-
-class HydraRenderEngine(bpy.types.RenderEngine):
-    """ Render addon with Hydra render delegate should inherit this class """
-
-    bl_use_shading_nodes_custom = False
-
-    delegate_id = ''
-    engine_ptr = None
-
-    def __del__(self):
-        if not self.engine_ptr:
-            return
-
-        _bpy_hydra.engine_free(self.engine_ptr)
-
-    @classmethod
-    def register(cls):
-        root_folder = "blender.shared" if platform.system() == 'Windows' else "lib"
-        os.environ['PXR_MTLX_STDLIB_SEARCH_PATHS'] = os.pathsep.join([
-            str(Path(bpy.app.binary_path).parent / f"{root_folder}/materialx/libraries"),
-            os.environ.get('PXR_MTLX_STDLIB_SEARCH_PATHS', "")])
-
-    @classmethod
-    def unregister(cls):
-        pass
-
-    def get_sync_settings(self, engine_type):
-        """
-        Provide settings for Blender scene delegate. Available settings:
-            `MaterialXFilenameKey` - if provided then MaterialX file will be provided directly to render delegate
-                                     without converting to HdMaterialNetwork
-        """
-        return {}
-
-    def get_render_settings(self, engine_type):
-        """
-        Provide render settings for render delegate. List of settings should be available in render delegate
-        documentation or in `pxr.UsdImagingGL.Engine.GetRendererSettingsList()`
-        """
-        return {}
-
-    # final render
-    def _update(self, depsgraph):
-        """This function is preferable to override in child classes instead of update()"""
-        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)
-
-        _bpy_hydra.engine_sync(self.engine_ptr, depsgraph.as_pointer(), bpy.context.as_pointer())
-
-    def update(self, data, depsgraph):
-        # If bl_use_gpu_context is true, this function is ignored and render() is used
-        if not self.bl_use_gpu_context:
-            self._update(depsgraph)
-
-    def render(self, depsgraph):
-        if self.bl_use_gpu_context:
-            self._update(depsgraph)
-
-        if not self.engine_ptr:
-            return
-
-        for key, val in self.get_render_settings('PREVIEW' if self.is_preview else 'FINAL').items():
-            _bpy_hydra.engine_set_render_setting(self.engine_ptr, key, val)
-
-        _bpy_hydra.engine_render(self.engine_ptr, depsgraph.as_pointer())
-
-    # viewport render
-    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)
-
-        _bpy_hydra.engine_sync(self.engine_ptr, depsgraph.as_pointer(), context.as_pointer())
-
-        for key, val in self.get_render_settings('VIEWPORT').items():
-            _bpy_hydra.engine_set_render_setting(self.engine_ptr, key, val)
-
-    def view_draw(self, context, depsgraph):
-        if not self.engine_ptr:
-            return
-
-        _bpy_hydra.engine_view_draw(self.engine_ptr, depsgraph.as_pointer(), context.as_pointer())
-
-
 def export_mtlx(material):
     """ Exports material to .mtlx file. It is called from Blender source code. """
     try:

scripts/modules/bpy_types.py

@@ -935,10 +935,6 @@ class PropertyGroup(StructRNA, metaclass=RNAMetaPropGroup):
     __slots__ = ()
 
 
-class RenderEngine(StructRNA, metaclass=RNAMeta):
-    __slots__ = ()
-
-
 class KeyingSetInfo(StructRNA, metaclass=RNAMeta):
     __slots__ = ()
 
@@ -1249,3 +1245,86 @@ class GeometryNode(NodeInternal):
     @classmethod
     def poll(cls, ntree):
         return ntree.bl_idname == 'GeometryNodeTree'
+
+
+class RenderEngine(StructRNA, metaclass=RNAMeta):
+    __slots__ = ()
+
+
+class HydraRenderEngine(RenderEngine):
+    __slots__ = ()
+
+    bl_use_shading_nodes_custom = False
+    bl_delegate_id = 'HdStormRendererPlugin'
+
+    def __init__(self):
+        self.engine_ptr = None
+
+    def __del__(self):
+        if hasattr(self, 'engine_ptr'):
+            if self.engine_ptr:
+                import _bpy_hydra
+                _bpy_hydra.engine_free(self.engine_ptr)
+
+    def get_sync_settings(self, engine_type: str):
+        """
+        Provide settings for Blender scene export. Available settings:
+            `MaterialXFilenameKey` - if provided then MaterialX file will be provided directly to render delegate
+                                     without converting to HdMaterialNetwork
+        """
+        return {}
+
+    def get_render_settings(self, engine_type: str):
+        """
+        Provide render settings for `HdRenderDelegate`.
+        """
+        return {}
+
+    # Final render.
+    def update(self, data, depsgraph):
+        import _bpy_hydra
+        import bpy
+
+        engine_type = 'PREVIEW' if self.is_preview else 'FINAL'
+        if not self.engine_ptr:
+            self.engine_ptr = _bpy_hydra.engine_create(self, engine_type, self.bl_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)
+
+        _bpy_hydra.engine_update(self.engine_ptr, depsgraph, bpy.context)
+
+        for key, val in self.get_render_settings('PREVIEW' if self.is_preview else 'FINAL').items():
+            _bpy_hydra.engine_set_render_setting(self.engine_ptr, key, val)
+
+    def render(self, depsgraph):
+        if not self.engine_ptr:
+            return
+
+        import _bpy_hydra
+        _bpy_hydra.engine_render(self.engine_ptr, depsgraph)
+
+    # Viewport render.
+    def view_update(self, context, depsgraph):
+        import _bpy_hydra
+        if not self.engine_ptr:
+            self.engine_ptr = _bpy_hydra.engine_create(self, 'VIEWPORT', self.bl_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)
+
+        _bpy_hydra.engine_update(self.engine_ptr, depsgraph, context)
+
+        for key, val in self.get_render_settings('VIEWPORT').items():
+            _bpy_hydra.engine_set_render_setting(self.engine_ptr, key, val)
+
+    def view_draw(self, context, depsgraph):
+        if not self.engine_ptr:
+            return
+
+        import _bpy_hydra
+        _bpy_hydra.engine_view_draw(self.engine_ptr, depsgraph, context)

scripts/site/sitecustomize.py

@@ -38,7 +38,11 @@ materialx_libs_dir = os.path.abspath(os.path.join(shared_lib_dir, "materialx", "
 materialx_libs_env = os.getenv("MATERIALX_SEARCH_PATH")
 if materialx_libs_env is None:
     os.environ["MATERIALX_SEARCH_PATH"] = materialx_libs_dir
-elif sys.platform == "win32":
-    os.environ["MATERIALX_SEARCH_PATH"] = materialx_libs_dir + ";" + materialx_libs_env
 else:
-    os.environ["MATERIALX_SEARCH_PATH"] = materialx_libs_dir + ":" + materialx_libs_env
+    os.environ["MATERIALX_SEARCH_PATH"] = materialx_libs_env + os.pathsep + materialx_libs_dir
+
+materialx_libs_env = os.getenv("PXR_MTLX_STDLIB_SEARCH_PATHS")
+if materialx_libs_env is None:
+    os.environ["PXR_MTLX_STDLIB_SEARCH_PATHS"] = materialx_libs_dir
+else:
+    os.environ["PXR_MTLX_STDLIB_SEARCH_PATHS"] = materialx_libs_env + os.pathsep + materialx_libs_dir

source/blender/makesrna/intern/rna_render.cc

@@ -1007,6 +1007,14 @@ static void rna_def_render_engine(BlenderRNA *brna)
   RNA_define_verify_sdna(1);
 }
 
+static void rna_def_hydra_render_engine(BlenderRNA *brna)
+{
+  /* This is implemented in Python. */
+  StructRNA *srna = RNA_def_struct(brna, "HydraRenderEngine", "RenderEngine");
+  RNA_def_struct_sdna(srna, "RenderEngine");
+  RNA_def_struct_ui_text(srna, "Hydra Render Engine", "Base class from USD Hydra based renderers");
+}
+
 static void rna_def_render_result(BlenderRNA *brna)
 {
   StructRNA *srna;
@@ -1235,6 +1243,7 @@ static void rna_def_render_pass(BlenderRNA *brna)
 void RNA_def_render(BlenderRNA *brna)
 {
   rna_def_render_engine(brna);
+  rna_def_hydra_render_engine(brna);
   rna_def_render_result(brna);
   rna_def_render_view(brna);
   rna_def_render_layer(brna);

source/blender/render/hydra/CMakeLists.txt

@@ -46,6 +46,8 @@ set(INC
   ../../gpu
   ../../gpu/intern
   ../../python/intern
+  # RNA_prototypes.h
+  ${CMAKE_BINARY_DIR}/source/blender/makesrna
   ..
   ${CMAKE_BINARY_DIR}/source/blender/makesrna/intern
 )
@@ -124,4 +126,5 @@ set(SRC
 
 blender_add_lib(bf_render_hydra "${SRC}" "${INC}" "${INC_SYS}" "${LIB}")
 
+# RNA_prototypes.h
 add_dependencies(bf_render_hydra bf_rna)

source/blender/render/hydra/python.cc

@@ -3,56 +3,26 @@
 
 #include <Python.h>
 
-#include <boost/python/extract.hpp>
+#include "RE_engine.h"
 
-#include <pxr/base/plug/plugin.h>
-#include <pxr/base/plug/registry.h>
-#include <pxr/usd/usd/stage.h>
-#include <pxr/usdImaging/usdImagingGL/engine.h>
+#include "bpy_rna.h"
 
-#include "BKE_appdir.h"
-#include "BLI_fileops.h"
-#include "BLI_path_util.h"
+#include "BKE_context.h"
+
+#include "RNA_prototypes.h"
+
+#include "scene_delegate/image.h"
 
 #include "final_engine.h"
 #include "preview_engine.h"
-#include "scene_delegate/image.h"
 #include "viewport_engine.h"
 
 namespace blender::render::hydra {
 
-static PyObject *register_plugins_func(PyObject * /*self*/, PyObject *args)
+template<typename T> T *pyrna_to_pointer(PyObject *pyobject, const StructRNA *rnatype)
 {
-  PyObject *pyplugin_dirs;
-  if (!PyArg_ParseTuple(args, "O", &pyplugin_dirs)) {
-    Py_RETURN_NONE;
-  }
-
-  std::vector<std::string> plugin_dirs;
-  PyObject *pyiter, *pyitem;
-
-  pyiter = PyObject_GetIter(pyplugin_dirs);
-  if (pyiter) {
-    while ((pyitem = PyIter_Next(pyiter))) {
-      plugin_dirs.push_back(PyUnicode_AsUTF8(pyitem));
-      Py_DECREF(pyitem);
-    }
-    Py_DECREF(pyiter);
-  }
-
-  pxr::PlugRegistry &registry = pxr::PlugRegistry::GetInstance();
-  registry.RegisterPlugins(plugin_dirs);
-
-  /* logging */
-  std::stringstream ss;
-  ss << "plugins=[";
-  for (auto &s : plugin_dirs) {
-    ss << s << ", ";
-  }
-  ss << "]";
-  CLOG_INFO(LOG_RENDER_HYDRA, 0, "Register %s", ss.str().c_str());
-
-  Py_RETURN_NONE;
+  const PointerRNA *ptr = pyrna_struct_as_ptr_or_null(pyobject, rnatype);
+  return (ptr) ? static_cast<T *>(ptr->data) : nullptr;
 }
 
 static PyObject *engine_create_func(PyObject * /*self*/, PyObject *args)
@@ -63,7 +33,7 @@ static PyObject *engine_create_func(PyObject * /*self*/, PyObject *args)
     Py_RETURN_NONE;
   }
 
-  RenderEngine *bl_engine = (RenderEngine *)PyLong_AsVoidPtr(pyengine);
+  RenderEngine *bl_engine = pyrna_to_pointer<RenderEngine>(pyengine, &RNA_RenderEngine);
 
   Engine *engine = nullptr;
   try {
@@ -111,16 +81,16 @@ static PyObject *engine_free_func(PyObject * /*self*/, PyObject *args)
   Py_RETURN_NONE;
 }
 
-static PyObject *engine_sync_func(PyObject * /*self*/, PyObject *args)
+static PyObject *engine_update_func(PyObject * /*self*/, PyObject *args)
 {
   PyObject *pyengine, *pydepsgraph, *pycontext;
   if (!PyArg_ParseTuple(args, "OOO", &pyengine, &pydepsgraph, &pycontext)) {
     Py_RETURN_NONE;
   }
 
-  Engine *engine = (Engine *)PyLong_AsVoidPtr(pyengine);
-  Depsgraph *depsgraph = (Depsgraph *)PyLong_AsVoidPtr(pydepsgraph);
-  bContext *context = (bContext *)PyLong_AsVoidPtr(pycontext);
+  Engine *engine = static_cast<Engine *>(PyLong_AsVoidPtr(pyengine));
+  Depsgraph *depsgraph = pyrna_to_pointer<Depsgraph>(pydepsgraph, &RNA_Depsgraph);
+  bContext *context = pyrna_to_pointer<bContext>(pycontext, &RNA_Context);
 
   CLOG_INFO(LOG_RENDER_HYDRA, 2, "Engine %p", engine);
   engine->sync(depsgraph, context);
@@ -136,8 +106,8 @@ static PyObject *engine_render_func(PyObject * /*self*/, PyObject *args)
     Py_RETURN_NONE;
   }
 
-  Engine *engine = (Engine *)PyLong_AsVoidPtr(pyengine);
-  Depsgraph *depsgraph = (Depsgraph *)PyLong_AsVoidPtr(pydepsgraph);
+  Engine *engine = static_cast<Engine *>(PyLong_AsVoidPtr(pyengine));
+  Depsgraph *depsgraph = pyrna_to_pointer<Depsgraph>(pydepsgraph, &RNA_Depsgraph);
 
   CLOG_INFO(LOG_RENDER_HYDRA, 2, "Engine %p", engine);
 
@@ -156,9 +126,9 @@ static PyObject *engine_view_draw_func(PyObject * /*self*/, PyObject *args)
     Py_RETURN_NONE;
   }
 
-  ViewportEngine *engine = (ViewportEngine *)PyLong_AsVoidPtr(pyengine);
-  Depsgraph *depsgraph = (Depsgraph *)PyLong_AsVoidPtr(pydepsgraph);
-  bContext *context = (bContext *)PyLong_AsVoidPtr(pycontext);
+  ViewportEngine *engine = static_cast<ViewportEngine *>(PyLong_AsVoidPtr(pyengine));
+  Depsgraph *depsgraph = pyrna_to_pointer<Depsgraph>(pydepsgraph, &RNA_Depsgraph);
+  bContext *context = pyrna_to_pointer<bContext>(pycontext, &RNA_Context);
 
   CLOG_INFO(LOG_RENDER_HYDRA, 3, "Engine %p", engine);
 
@@ -235,11 +205,9 @@ static PyObject *cache_or_get_image_file_func(PyObject * /*self*/, PyObject *arg
 }
 
 static PyMethodDef methods[] = {
-    {"register_plugins", register_plugins_func, METH_VARARGS, ""},
-
     {"engine_create", engine_create_func, METH_VARARGS, ""},
     {"engine_free", engine_free_func, METH_VARARGS, ""},
-    {"engine_sync", engine_sync_func, METH_VARARGS, ""},
+    {"engine_update", engine_update_func, METH_VARARGS, ""},
     {"engine_render", engine_render_func, METH_VARARGS, ""},
     {"engine_view_draw", engine_view_draw_func, METH_VARARGS, ""},
     {"engine_set_sync_setting", engine_set_sync_setting_func, METH_VARARGS, ""},

source/blender/render/intern/engine.cc

@@ -919,9 +919,16 @@ static void engine_render_view_layer(Render *re,
 
   /* Sync data to engine, within draw lock so scene data can be accessed safely. */
   if (use_engine) {
+    const bool use_gpu_context = (engine->type->flag & RE_USE_GPU_CONTEXT);
+    if (use_gpu_context) {
+      DRW_render_context_enable(engine->re);
+    }
     if (engine->type->update) {
       engine->type->update(engine, re->main, engine->depsgraph);
     }
+    if (use_gpu_context) {
+      DRW_render_context_disable(engine->re);
+    }
   }
 
   if (re->draw_lock) {