message: Don't commit the model while it's being rendered asynchronously
  Fixes crash in bouncing spheres tutorial
diff: @@ -337,8 +337,9 @@ void displayCallback(GLFWOSPRayWindow *glfwOSPRayWindow)
  updateSpheresCoordinates();
  updateSpheresGeometry();
  - // commit the model since the spheres geometry changed
  - ospCommit(g_model);
  + // queue the model to be committed since it changed, however don't commit
  + // it immediately because it's being rendered asynchronously
  + glfwOSPRayWindow->addObjectToCommit(g_model);
  // update the model on the GLFW window
  glfwOSPRayWindow->setModel(g_model);
  