Camera Fork

ScreenFork.cs

using UnityEngine;

[ExecuteInEditMode, RequireComponent(typeof(Camera))]
public class ScreenFork: MonoBehaviour {

    public RenderTexture copyTo;

    private void OnRenderImage(RenderTexture src, RenderTexture dest) {
        Graphics.Blit(src, dest);
        if(copyTo != null)
            Graphics.Blit(src, copyTo);
    }
}