# WaitForEndOfFrame

> Suspends a coroutine until the end of the frame after Unity has rendered every Camera and GUI, just before displaying the frame on screen.

## Definition

* **Type:** Class
* **Namespace:** [UnityEngine](/engine/6000.7/script-reference/unityengine.md)
* **Assembly:** UnityEngine.CoreModule
* **Inherits from:** [YieldInstruction](/engine/6000.7/script-reference/unityengine/yieldinstruction.md)

```csharp
public sealed class WaitForEndOfFrame : YieldInstruction
```

## Remarks

`WaitForEndOfFrame` can only be used with a `yield` statement in coroutines.

You can use `WaitForEndOfFrame` to read the display into a Texture, encode it as an image file, and store it on a device.

Switching from the Game view to the Scene view causes `WaitForEndOfFrame` to freeze. It only continues when the application switches back to the Game view. This can only happen when the application is working in the Unity Editor.

**Note:** `WaitForEndOfFrame` does not run when you run the Editor in batch mode, even if the script it's in uses [ExecuteInEditMode](/engine/6000.7/script-reference/unityengine/executeineditmode.md) or [ExecuteAlways](/engine/6000.7/script-reference/unityengine/executealways.md).

Additional Resources: [Texture2D.ReadPixels](/engine/6000.7/script-reference/unityengine/texture2d/readpixels.md), [ExecuteAlways](/engine/6000.7/script-reference/unityengine/executealways.md).

```csharp
using System.IO;
using UnityEngine;
using UnityEngine.Networking;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    // Take a shot immediately
    IEnumerator Start()
    {
        UploadPNG();
        yield return null;
    }

    IEnumerator UploadPNG()
    {
        // We should only read the screen buffer after rendering is complete
        yield return new WaitForEndOfFrame();

        // Create a texture the size of the screen, RGB24 format
        int width = Screen.width;
        int height = Screen.height;
        Texture2D tex = new Texture2D(width, height, TextureFormat.RGB24, false);

        // Read screen contents into the texture
        tex.ReadPixels(new Rect(0, 0, width, height), 0, 0);
        tex.Apply();

        // Encode texture into PNG
        byte[] bytes = tex.EncodeToPNG();
        Destroy(tex);

        // For testing purposes, also write to a file in the project folder
        // File.WriteAllBytes(Application.dataPath + "/../SavedScreen.png", bytes);


        // Create a Web Form
        WWWForm form = new WWWForm();
        form.AddField("frameCount", Time.frameCount.ToString());
        form.AddBinaryData("fileUpload", bytes);

        // Upload to a cgi script
        var w = UnityWebRequest.Post("http://localhost/cgi-bin/env.cgi?post", form);
        yield return w.SendWebRequest();
        if (w.result != UnityWebRequest.Result.Success)
            print(w.error);
        else
            print("Finished Uploading Screenshot");
        yield return null;
    }
}
```

```csharp
using UnityEngine;
using System.Collections;

public class ExampleScript : MonoBehaviour
{
    // A script that shows destination alpha channel in the game view.

    Material mat;

    void CreateMaterial()
    {
        // Unity has a built-in shader that is useful for drawing
        // simple colored things. In this case, we just want to use
        // a blend mode that inverts destination colors.
        var shader = Shader.Find("Hidden/Internal-Colored");
        mat = new Material(shader);
        mat.hideFlags = HideFlags.HideAndDontSave;
        // Set blend mode to show destination alpha channel.
        mat.SetInt("_SrcBlend", (int)UnityEngine.Rendering.BlendMode.DstAlpha);
        mat.SetInt("_DstBlend", (int)UnityEngine.Rendering.BlendMode.Zero);
        // Turn off backface culling, depth writes, depth test.
        mat.SetInt("_Cull", (int)UnityEngine.Rendering.CullMode.Off);
        mat.SetInt("_ZWrite", 0);
        mat.SetInt("_ZTest", (int)UnityEngine.Rendering.CompareFunction.Always);
    }

    public IEnumerator Start()
    {
        CreateMaterial();
        while (true)
        {
            // Wait until all rendering + UI is done.
            yield return new WaitForEndOfFrame();
            // Draw a quad that shows alpha channel.
            GL.PushMatrix();
            GL.LoadOrtho();
            mat.SetPass(0);
            GL.Begin(GL.QUADS);
            GL.Vertex3(0, 0, 0);
            GL.Vertex3(1, 0, 0);
            GL.Vertex3(1, 1, 0);
            GL.Vertex3(0, 1, 0);
            GL.End();
            GL.PopMatrix();
        }
        yield return null;
    }
}
```

Additional Resources: [AsyncOperation](/engine/6000.7/script-reference/unityengine/asyncoperation.md), [WaitForSeconds](/engine/6000.7/script-reference/unityengine/waitforseconds.md), [WaitForFixedUpdate](/engine/6000.7/script-reference/unityengine/waitforfixedupdate.md), [WaitForSecondsRealtime](/engine/6000.7/script-reference/unityengine/waitforsecondsrealtime.md), [WaitUntil](/engine/6000.7/script-reference/unityengine/waituntil.md),[WaitWhile](/engine/6000.7/script-reference/unityengine/waitwhile.md).