让物体上下移动

    float radian;
    float Perdian = 0.2f;
    Vector3 oldpos;
    void Start () {
        oldpos = transform.position;
    }
    void Update () {
        radian += Perdian;
        float dy = Mathf.Cos(radian)*10;
        transform.position = oldpos + new Vector3(0, dy, 0);
    }
}