计算角色和物体之间距离来触发动画【Unity3d】

function Update () {
     var aa = GameObject.Find("tishen");
     var bb =GameObject.Find("xar");
     var dis : float=Vector3.Distance(aa.transform.position, bb.transform.position);

     if (dis>5.0 && dis<=7.0 )
     {
           animation.Play("xarzx");
     }

     else if (dis>7.0)
     {
           animation.Play("idle");
     }
     else

           animation.Play("xarjh");
}