scripts/modules/bpy_hydra.py

@@ -92,6 +92,9 @@ class HydraRenderEngine(bpy.types.RenderEngine):
 
     # final render
     def update(self, data, depsgraph):
+        # Note: if bl_use_gpu_context = True, leave this function empty and move engine creation 
+        #       and syncing to render() function
+
         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:

source/blender/render/hydra/final_engine.cc

@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: Apache-2.0
  * Copyright 2011-2022 Blender Foundation */
 
-#include <pxr/imaging/glf/drawTarget.h>
+#include <pxr/imaging/garch/glApi.h>
 #include <pxr/imaging/hd/light.h>
 
 #include "BKE_lib_id.h"
@@ -115,7 +115,7 @@ void FinalEngine::prepare_for_render(Depsgraph *depsgraph)
       std::vector<float>(resolution_[0] * resolution_[1] * 4)); /* 4 - number of channels. */
 }
 
-void FinalEngineGL::render(Depsgraph *depsgraph)
+void FinalEngineGPU::render(Depsgraph *depsgraph)
 {
   prepare_for_render(depsgraph);
 
@@ -155,10 +155,11 @@ void FinalEngineGL::render(Depsgraph *depsgraph)
   }
   GPU_framebuffer_clear_color_depth(framebuffer, clear_color, 1.0f);
 
-  // Generate vertex array
-  GLuint vao;
-  glGenVertexArrays(1, &vao);
-  glBindVertexArray(vao);
+  /* Important: we have to create and bind at least one  Vertex Array Object (VAO) before render
+     execution: More info at https://open.gl/drawing */
+  GLuint VAO;
+  glGenVertexArrays(1, &VAO);
+  glBindVertexArray(VAO);
 
   engine_->Execute(render_index_.get(), &tasks_);
 
@@ -197,6 +198,7 @@ void FinalEngineGL::render(Depsgraph *depsgraph)
   MEM_freeN(data);
   update_render_result();
 
+  glDeleteVertexArrays(1, &VAO);
   GPU_framebuffer_free(framebuffer);
   GPU_texture_free(tex_color);
   GPU_texture_free(tex_depth);

source/blender/render/hydra/final_engine.h

@@ -26,7 +26,7 @@ class FinalEngine : public Engine {
   pxr::GfVec2i resolution_;
 };
 
-class FinalEngineGL : public FinalEngine {
+class FinalEngineGPU : public FinalEngine {
  public:
   using FinalEngine::FinalEngine;
 

source/blender/render/hydra/python.cc

@@ -75,7 +75,7 @@ static PyObject *engine_create_func(PyObject * /*self*/, PyObject *args)
     }
     else {
       if (bl_engine->type->flag & RE_USE_GPU_CONTEXT) {
-        engine = new FinalEngineGL(bl_engine, render_delegate_id);
+        engine = new FinalEngineGPU(bl_engine, render_delegate_id);
       }
       else {
         engine = new FinalEngine(bl_engine, render_delegate_id);