[Unity基础]RenderTexture

Posted 2020-11-06 lyh916

参考链接：

https://www.cnblogs.com/Jimm/p/5951362.html

 

一.相关API

1.Texture2D.ReadPixels

从RenderTexture.active中复制像素，以左下角为原点。

2.MonoBehaviour.OnPostRender

当相机渲染完所有物体就会调用该方法，并且只有当这个脚本挂在相机时才会调用。

 

二.测试

新建一个场景，新建一个camera和一个go，把go设置为一个单独的层，让camera单独照这个层，主camera不要照这个层。调整camera的深度和targetTexture。

 1 using UnityEngine;
 2 using System.Collections;
 3 using UnityEngine.UI;
 4 using System.IO;
 5 
 6 public class TestRenderTexture : MonoBehaviour {
 7 
 8     public Camera camera;
 9     public RawImage rawImage;
10     bool isScreenShot = false;
11 
12     void Update()
13     {
14         //将镜头的画面保存到本地
15         if (Input.GetKeyDown(KeyCode.Q))
16         {
17             Texture2D tex = RenderTexture2Texture2D(camera.targetTexture);
18 
19             //展示
20             rawImage.texture = tex;
21 
22             //保存到本地
23             byte[] bytes = tex.EncodeToPNG();
24             File.WriteAllBytes(Application.dataPath + "/RenderTexture/Test.png", bytes);
25             UnityEditor.AssetDatabase.Refresh();
26         }
27 
28         //屏幕截图(方法1)
29         if (Input.GetKeyDown(KeyCode.W))
30         {
31             StartCoroutine(ScreenShotIEnumerator());
32         }
33 
34         //屏幕截图(方法2)
35         if (Input.GetKeyDown(KeyCode.E))
36         {
37             isScreenShot = true;
38         }
39     }
40 
41     public IEnumerator ScreenShotIEnumerator()
42     {
43         yield return new WaitForEndOfFrame();
44         rawImage.texture = ScreenShot();
45     }
46 
47     private void OnPostRender()
48     {
49         //Debug.Log("OnPostRender");
50         if (isScreenShot)
51         {
52             isScreenShot = false;
53             rawImage.texture = ScreenShot();
54         }
55     }
56 
57     //屏幕截图
58     public Texture2D ScreenShot()
59     {
60         Texture2D tex = new Texture2D(Screen.width, Screen.height, TextureFormat.ARGB32, false);
61         tex.ReadPixels(new Rect(0, 0, Screen.width, Screen.height), 0, 0);
62         tex.Apply();
63         return tex;
64     }
65 
66     //RenderTexture转Texture2D
67     public Texture2D RenderTexture2Texture2D(RenderTexture rt)
68     {
69         RenderTexture preRT = RenderTexture.active;
70         RenderTexture.active = rt;
71         Texture2D tex = new Texture2D(rt.width, rt.height, TextureFormat.ARGB32, false);
72         tex.ReadPixels(new Rect(0, 0, rt.width, rt.height), 0, 0);
73         tex.Apply();
74         RenderTexture.active = preRT;
75         return tex;
76     }
77 }