private const float maximumDelay = 15f; // Maximaler Dauer der extrapolation der Position eines Markers

    // Start is called before the first frame update
    void Start()
    {
        // starten des Vuforia Tracking Moduls
        trackerDevice = TrackerManager.Instance.InitTracker <PositionalDeviceTracker>();

        // Referenzbildung der Marker
        savedBuildings = FindObjectOfType <building>();
        targets        = savedBuildings.GetAllTargets();

        // 3D-Modelle deaktieren
        building.gameObject.SetActive(false);
    }