private void Update()
    {
        int playerMask = 1 << 9;
        playerMask = ~playerMask;
        RaycastHit RaHit;
        if (Physics.Raycast(transform.position, Vector3.down, out RaHit, 4.0f, playerMask))
        {
            transform.rotation = Quaternion.FromToRotation(transform.up, RaHit.normal);
        }
        Debug.DrawRay(transform.position, RaHit.point, Color.green);
    }