Unity调用外部摄像头，全屏显示摄像头画面

有两种方法，常用的是GUI方法，代码如下：

public class CameraTest : MonoBehaviour {

    WebCamTexture camTexture;

    void Start () {
        StartCoroutine(CallCamera());
    }

    IEnumerator CallCamera()
    {
        yield return Application.RequestUserAuthorization(UserAuthorization.WebCam);
        if (Application.HasUserAuthorization(UserAuthorization.WebCam))
        {
            if (camTexture != null)
                camTexture.Stop();

            WebCamDevice[] cameraDevices = WebCamTexture.devices;

            string deviceName = cameraDevices[0].name;
            Debug.Log(deviceName);

            camTexture = new WebCamTexture(deviceName);
            camTexture.Play();
        }
    }

    void OnGUI()
    {
        if(camTexture!=null)
        {
            GUI.DrawTexture(new Rect(0, 0, Screen.width, Screen.height), camTexture, ScaleMode.StretchToFill);
       }
    }
}

　　

GUI已经被抛弃，效率,DrawCall,适配等各种差，现使用UGUI实现：

public class CameraTest : MonoBehaviour {

    WebCamTexture camTexture;

    Image img;

    public GameObject quad;

    void Start () {
        img = GetComponentInChildren<Image>();
        StartCoroutine(CallCamera());
    }

    IEnumerator CallCamera()
    {
        yield return Application.RequestUserAuthorization(UserAuthorization.WebCam);
        if (Application.HasUserAuthorization(UserAuthorization.WebCam))
        {
            if (camTexture != null)
                camTexture.Stop();

            WebCamDevice[] cameraDevices = WebCamTexture.devices;

            string deviceName = cameraDevices[0].name;
            Debug.Log(deviceName);

            camTexture = new WebCamTexture(deviceName);
            img.canvasRenderer.SetTexture(camTexture); //注意改行代码
            camTexture.Play();
        }
    }

}