@Override
public void start(Stage stage) throws IOException {

  // set up the scene
  FXMLLoader loader = new FXMLLoader(getClass().getResource("/orbit_the_camera_around_an_object/main.fxml"));
  Parent root = loader.load();
  controller = loader.getController();
  Scene scene = new Scene(root);

  // set up the stage
  stage.setTitle("Orbit the Camera Around an Object Sample");
  stage.setWidth(800);
  stage.setHeight(700);
  stage.setScene(scene);
  stage.show();
}