int i ;

    int j ;

    public int w, h ;//w,h可变,适应其它图片

    public float stepTime ;

    // Use this for initialization

    void Start () {

        renderer.material.mainTextureScale = new Vector2(1f/(float)w, 1f/(float)h) ;

    }

    // Update is called once per frame

    void Update () {

        if(Time.time>stepTime){

            renderer.material.mainTextureOffset = new Vector2(1f/(float)w*i, 1f/(float)h*j) ;

            if(i+>=w) j = (j+)%h ;

            i = (i+)%w ;

            stepTime = Time.time + 0.5f ;

        }

    }