WaitForEndOfFrame

Description

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

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 or ExecuteAlways.

Additional resources: Texture2D.ReadPixels, ExecuteAlways.

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;
    }
}

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, WaitForSeconds, WaitForFixedUpdate, WaitForSecondsRealtime, WaitUntil,WaitWhile.

Inherited Members