Unity3D调用摄像头显示当前拍摄画面

using UnityEngine;
using System.Collections;

public class CameraTest : MonoBehaviour
{
public WebCamTexture cameraTexture;
public string cameraName="";
private bool isPlay = false;
// Use this for initialization
void Start()
{
StartCoroutine(Test());
}

// Update is called once per frame
void Update()
{

}

IEnumerator Test()
{
yield return Application.RequestUserAuthorization(UserAuthorization.WebCam);
if (Application.HasUserAuthorization(UserAuthorization.WebCam))
{
WebCamDevice[] devices = WebCamTexture.devices;
cameraName = devices[0].name;
cameraTexture = new WebCamTexture(cameraName, 400, 300, 15);
cameraTexture.Play();
isPlay = true;
}
}

void OnGUI()
{
if (isPlay)
{
GUI.DrawTexture(new Rect(0, 0, 400, 300), cameraTexture, ScaleMode.ScaleToFit);
}
}
}