unity 打开webcam

using UnityEngine;
using System.Collections;

public class OpenCamera : MonoBehaviour {
public WebCamTexture tex;
private string deviceName="";

// Use this for initialization
void Start () {
StartCoroutine(openCam());

}

IEnumerator openCam()
{
yield return Application.RequestUserAuthorization(UserAuthorization.WebCam);//授权
if (Application.HasUserAuthorization(UserAuthorization.WebCam))
{
WebCamDevice[] devices = WebCamTexture.devices;
deviceName = devices[0].name;
print(deviceName);

//设置摄像机摄像的区域
tex = new WebCamTexture(deviceName, 400, 300, 12);
GetComponent<Renderer>().material.mainTexture = tex;///材质赋值不能在外面赋值，不然画面传不进来
tex.Play();//开始摄像
}
}
}