使用带有SKTransition的presentScene的GameViewController到GameScene

Question

尝试从GameViewController首次加载GameScene时执行SKTransition，但似乎没有任何事情发生。我们不能直接从GameViewController呈现场景时执行一些转换吗？在我看来，正常的当前场景正在发挥作用，而不是那个有过渡的场景，这对我来说非常有趣。这是代码：

 class GameViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        if let view = self.view as! SKView? {

            let scene = GameScene(size: view.bounds.size)
                // Set the scale mode to scale to fit the window
                scene.scaleMode = .aspectFill
                //transition
                let transition = SKTransition.doorsOpenVertical(withDuration: 2)
                // Present the scene
                view.presentScene(scene, transition: transition)

            view.ignoresSiblingOrder = true

            view.showsFPS = true
            view.showsNodeCount = true
        }
    }
}

    class GameScene: SKScene {

    override func didMove(to view: SKView) {
        self.backgroundColor = SKColor.red
    }
}

请解决查询。