2d场景背景无限滚动

之前都是直接借用的DoTween插件，两个背景无限交替位置进行，还有就是三个背景在利用Trigger进行判断显示与否循环；

　　示例脚本：

　　

 private List<RectTransform> m_ScrollGroup;
    private RectTransform[] _ts;
    void Awake()
    {
        m_ScrollGroup = new List<RectTransform>();
        _ts = transform.GetComponentsInChildren<RectTransform>();
        foreach(RectTransform t in _ts)
        {
            if(t.name.StartsWith("Background"))
            {
                m_ScrollGroup.Add(t);                
            }           
        }
        //Debug.Log(m_ScrollGroup.Count + ":" + m_ScrollGroup[0]);//2 object
    }
    private Vector2 m_StartPos = new Vector2(788, 0);
    private int m_Speed = 50;   
    void Update () {
        PosLimit();
        m_ScrollGroup[0].transform.Translate(Vector3.left * Time.deltaTime * m_Speed);
        m_ScrollGroup[1].transform.Translate(Vector3.left * Time.deltaTime * m_Speed);
        //m_ScrollGroup[0].position = Vector2.Lerp(new Vector2(-11, 0), new Vector2(-800, 0), 60);       
    }
    public void PosLimit()
    {
        //width 800 height600
        if (m_ScrollGroup[0].position.x <= -400f)
        {
            m_ScrollGroup[0].position = new Vector2(1198f, m_ScrollGroup[0].position.y);
        }
        if (m_ScrollGroup[1].position.x <= -400f)
        {
            m_ScrollGroup[1].position = new Vector2(1198f, m_ScrollGroup[1].position.y);
        }

    }