@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();
}