private void Run()
        {
            //initialize FaceTracker
            faceTracker = new FaceTracker(tracker_model_json_filepath);
            //initialize FaceTrackerParams
            faceTrackerParams = new FaceTrackerParams();

            cascade = new CascadeClassifier();
            cascade.load(haarcascade_frontalface_alt_xml_filepath);
            //            if (cascade.empty())
            //            {
            //                Debug.LogError("cascade file is not loaded.Please copy from “FaceTrackerExample/StreamingAssets/” to “Assets/StreamingAssets/” folder. ");
            //            }

            webCamTextureToMatHelper = gameObject.GetComponent <WebCamTextureToMatHelper>();
            webCamTextureToMatHelper.Init();
        }
 /// <summary>
 /// Raises the change camera button event.
 /// </summary>
 public void OnChangeCameraButton()
 {
     webCamTextureToMatHelper.Init(null, webCamTextureToMatHelper.requestWidth, webCamTextureToMatHelper.requestHeight, !webCamTextureToMatHelper.requestIsFrontFacing);
 }