public Transform target;
    public float distance ;
    public float targetHeight;
    private float x = 0.0f;
    private float y = 0.0f;  
     
    void Start () {
        var angles = transform.eulerAngles;
        x = angles.x;
        y = angles.y;
    }
     
    void LateUpdate () 
    {
       if(!target)
          return;
       
       y = target.eulerAngles.y;

       // ROTATE CAMERA:
       Quaternion rotation = Quaternion.Euler(x, y, 0);
       transform.rotation = rotation;
       
       // POSITION CAMERA:
       Vector3 position = target.position - (rotation * Vector3.forward * distance + new Vector3(0,-targetHeight,0));
       transform.position = position;
    }