Vuforia切换回识别场景后黑屏解决

IEnumerator LoadScenes(string sceneName)
    {
        if (TrackerManager.Instance.GetTracker<MarkerTracker>() != null)
        {
            MarkerTracker marker = TrackerManager.Instance.GetTracker<MarkerTracker>();
            marker.Stop();
        }

        if (TrackerManager.Instance.GetTracker<TextTracker>() != null)
        {
            TextTracker textTracker = TrackerManager.Instance.GetTracker<TextTracker>();
            textTracker.Stop();
        }

        if (TrackerManager.Instance.GetTracker<ObjectTracker>() != null)
        {
            ObjectTracker objTracker = TrackerManager.Instance.GetTracker<ObjectTracker>();
            objTracker.Stop();
        }
　　　　　
　　　　//此处返回waitForSeconds,因为我是在OnGUI中启动协程，如果不用WaitForSeconds,就会识别两次模型
        yield return new WaitForSeconds(0.5f);  //WaitForEndOfFrame();

        Application.LoadLevel(sceneName);
    }