private void Awake()
 {
     // using Singleton Design Pattern
     if (singleton == null)
     {
         singleton = this;
     }
     _myTransform = transform;
     // 实际上这个是相机离人物的水平距离
     _defaultPos = cameraTransform.localPosition.z;
     //
     _ignoreLayers = ~(1 << 8 | 1 << 9 | 1 << 10);
 }
 private void Awake()
 {
     _cameraHandler = CameraHandler.singleton;
 }