Unity 2d 不基于射线检测使鼠标改变物体方向

    void Rotate()
    {
        Vector3 mousePoint = Camera.main.ScreenToWorldPoint(Input.mousePosition);
        mousePoint.z = transform.position.z;
        Vector3 dir = (mousePoint - transform.position).normalized;
        transform.up = dir;
    }

PS:

然后在Update方法中调用。