在unity3d中可能會遇到截圖然後儲存到材質中作為某種顯示使用，網上的程式碼基本都是截圖是的截圖。今天介紹一種截指定區域或者自定義區域的方法。

using UnityEngine;
using System.Collections;
using System.IO;
using UnityEngine.UI;
using UnityEngine.SceneManagement;
using System;

public class TakePhoto : MonoBehaviour
{
    public static TakePhoto _Instance;
    // 拍照擷取的區域
 

    [Tooltip("拍照擷取的區域")]
    public Image im；
    //用於控制指定區域的左上點和右下點，並且他們的錨點分別在左上和右下
     public Image zuodingIma, xiaIma;
    //展示拍照的RawImage
    public RawImage[] tx;
    public RawImage showTx;
    int capx = 0;
    int capy = 0;
    int capwidth = 0;
    int capheight = 0;
    int index = 0;
    Texture2D t;


    private
 
 void Awake()
    {
        _Instance = this;


    }


    /// <summary>
    /// 將截圖區域的Pivot設定為左下角，即 0  0,thisIm是具體的截圖區域
    /// </summary>
    void SetPivot(Image thisIm)
    {
        thisIm.GetComponent<RectTransform>().pivot = new Vector2(0, 0);

    }


    public void Shoot()
    {
        AudioController.instance.PlayFX("shoot"
 
);
        StartCoroutine(GetScreenTexture());
    }
    /// <summary>
    /// 截指定區域圖並賦值給材質
    /// </summary>
    /// <returns></returns>
    IEnumerator GetScreenTexture()
    {
        capx = Mathf.Abs((int)im.gameObject.transform.position.x);
        capy = Mathf.Abs((int)im.gameObject.transform.position.y);

        capwidth = Mathf.Abs((int)(xiaIma.gameObject.transform.position.x - im.gameObject.transform.position.x)) ;
        capheight = Mathf.Abs((int)(zuodingIma.gameObject.transform.position.y - im.gameObject.transform.position.y)) ;

        yield return new WaitForEndOfFrame();
        t = new Texture2D(capwidth, capheight, TextureFormat.RGB24, false);//需要正確設定好圖片儲存格式
        t.ReadPixels(new Rect(capx, capy, capwidth, capheight), 0, 0, false);//按照設定區域讀取畫素；注意是以左下角為原點讀取
  t.Compress(false);
        t.Apply();
        //二進位制轉換，儲存到手機
        // byte[] byt = t.EncodeToPNG();
        //   File.WriteAllBytes(Application.dataPath + this.index + ".png", byt);



    }

    /// <summary>
    ///截圖不滿意重拍
    /// </summary>
    public void ReShootPhoto()
    {

        //重拍

    }
    /// <summary>
    ///  繼續拍照
    /// </summary>
    public void ContinueShoot()
    {


    }


    public string deviceName;

    WebCamTexture tex;//接收返回的圖片資料
    IEnumerator Camera()
    {
       // yield return Application.RequestUserAuthorization(UserAuthorization.WebCam);//授權
        int height = Screen.height;
        int width = Screen.width;
        if (Application.HasUserAuthorization(UserAuthorization.WebCam))
        {
            WebCamDevice[] devices = WebCamTexture.devices;
            deviceName = devices[0].name;
            //設定攝像機攝像的區域
            tex = new WebCamTexture(deviceName, width, height, 40);
            tex.Play();//開始攝像
        }
        yield return new WaitForSeconds(0.1f);
    }
}