コライダーの範囲内か範囲外なのかを取得して動画を再生させる

using UnityEngine;
using System.Collections;

public class TestTriggerMovie : MonoBehaviour {
    //settings
    public GameObject _trigger;
    public GameObject _target;
    //objects
    private Bounds TriggerBounds;

    void Start ()
    {
        TriggerBounds = _trigger.transform.collider.bounds;
        _target = this.transform.FindChild("Plane").gameObject;     
    }

    void Update () {
        this.transform.position += new Vector3(0, 0, 1); 
        Vector3 pos = this.transform.localPosition;
        //Debug.Log(pos);    
        if (TriggerBounds.Contains(pos) == false)
        {
            Debug.Log("Fire");
            MovieTexture movieTexture = _target.renderer.material.mainTexture as MovieTexture;
            //movieTexture.loop = true;
            movieTexture.Play();
        } 
    }

}