public void Update()
 {
     if (isUptate)
     {
         if (isFadeOut)
         {
             time += Time.deltaTime;
             if (time >= maxTime || !audioManager.IsPlaying())
             {
                 isFadeOut = false;
                 time      = maxTime;
                 if (clip != null)
                 {
                     audioManager.SetClip(clip);
                     audioManager.play();
                 }
                 else
                 {
                     audioManager.stop();
                 }
             }
         }
         else
         {
             time -= Time.deltaTime;
             if (time <= 0)
             {
                 isUptate = false;
                 time     = 0;
             }
         }
         audioManager.SetVolume((maxTime - time) / maxTime);
     }
 }
 // Update is called once per frame
 void Update()
 {
     if (lastPosition == target.position && music.GetVolume() != 0)
     {
         music.SetVolume(0);
     }
     else
     {
         float sqrMagnitude = (lastPosition - target.position).magnitude;
         if (sqrMagnitude > maxDistance)
         {
             music.SetVolume(1);
         }
         else
         {
             music.SetVolume(sqrMagnitude / maxDistance);
         }
     }
     lastPosition = target.position;
 }