1.这里我代码没啥问题~~~编辑器里也没毛病

 void Start()
    {
        // 加载底图和上层图片
        string backgroundImagePath = Application.streamingAssetsPath + "/background.jpg";
        Texture2D backgroundTexture = new Texture2D(2, 2);
        byte[] backgroundImageData = System.IO.File.ReadAllBytes(backgroundImagePath);
        backgroundTexture.LoadImage(backgroundImageData);

        string overlayImagePath = Application.streamingAssetsPath + "/1.png";
        Texture2D overlayTexture = new Texture2D(2, 2);
        byte[] overlayImageData = System.IO.File.ReadAllBytes(overlayImagePath);
        overlayTexture.LoadImage(overlayImageData);


        // 创建合成材质
        Material imageProcessingMaterial = new Material(Shader.Find("Custom/ImageProcessingShader"));
        imageProcessingMaterial.SetTexture("_MainTex", backgroundTexture);
        imageProcessingMaterial.SetTexture("_OverlayTex", overlayTexture);

        // 创建RenderTexture，并渲染到其中
        RenderTexture renderTexture = new RenderTexture(backgroundTexture.width, backgroundTexture.height, 0);
        Graphics.Blit(null, renderTexture, imageProcessingMaterial);

        // 将RenderTexture转换为Texture2D
        Texture2D outputTexture = new Texture2D(renderTexture.width, renderTexture.height, TextureFormat.RGBA32, false);
        RenderTexture.active = renderTexture;
        outputTexture.ReadPixels(new UnityEngine.Rect(0, 0, renderTexture.width, renderTexture.height), 0, 0);
        outputTexture.Apply();
        RenderTexture.active = null;

        // 显示处理后的图像
        raw.texture = outputTexture;
    }

2.但是打包完之后，原本要合并的图片却没有反应

3.解决方法如下：

选择Edit->ProjectSettings->Graphics：

在ProjectSettings里面的Graphics，Always Included Shaders数组更改size，并将所需用到的Shader拖入其中