XNA截图显示了Bloom之前,而不是最终渲染

Question

我有一个使用Reach图形设置在C#XNA 4.0中编码的Windows平台游戏.我的项目基于GameStateManagement示例,但后来我添加了Bloom和spriteSheet/spriteBatch功能.

我希望保存最终屏幕输出的屏幕截图.但是,当我保存我的截图时,它只显示Bloom应用之前和我的HUD文本显示之前的渲染(我在Bloom之后绘制).在这两个过程之后,我的Draw方法结束时保存了截图.

我尝试过各种各样的事情.安德鲁的答案在这里拍摄XNA中的屏幕截图是有帮助的并且可以保存图像; 但是,它并没有保存最终渲染.

我有一种感觉它与绽放过程或spograbatch有关.

这是我的代码:

    example {
    public override void Draw(GameTime gameTime)
    {
        ScreenManager.GraphicsDevice.SetRenderTarget(sceneRenderTarget);
        // Clear the screen to black
        ScreenManager.GraphicsDevice.Clear(ClearOptions.Target,
                                           Color.Black, 0, 0);
        SpriteBatch spriteBatch = ScreenManager.SpriteBatch;
        spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend);

    // then i draw all my game stuff

        spriteBatch.End();

        #region Post-Processing & Bloom
        ScreenManager.GraphicsDevice.SamplerStates[1] = SamplerState.LinearClamp;

        // Pass 1: draw the scene into rendertarget 1, using a
        // shader that extracts only the brightest parts of the image.
        bloomExtractEffect.Parameters["BloomThreshold"].SetValue(
            Settings.BloomThreshold);

        DrawFullscreenQuad(sceneRenderTarget, renderTarget1,
                           bloomExtractEffect,
                           IntermediateBuffer.PreBloom);

        // Pass 2: draw from rendertarget 1 into rendertarget 2,
        // using a shader to apply a horizontal gaussian blur filter.
        SetBlurEffectParameters(1.0f / (float)renderTarget1.Width, 0);

        DrawFullscreenQuad(renderTarget1, renderTarget2,
                           gaussianBlurEffect,
                           IntermediateBuffer.BlurredHorizontally);

        // Pass 3: draw from rendertarget 2 back into rendertarget 1,
        // using a shader to apply a vertical gaussian blur filter.
        SetBlurEffectParameters(0, 1.0f / (float)renderTarget1.Height);

        DrawFullscreenQuad(renderTarget2, renderTarget1,
                           gaussianBlurEffect,
                           IntermediateBuffer.BlurredBothWays);

        // Pass 4: draw both rendertarget 1 and the original scene
        // image back into the main backbuffer, using a shader that
        // combines them to produce the final bloomed result.
        ScreenManager.GraphicsDevice.SetRenderTarget(null);

        EffectParameterCollection parameters = bloomCombineEffect.Parameters;

        parameters["BloomIntensity"].SetValue(Settings.BloomIntensity);
        parameters["BaseIntensity"].SetValue(Settings.BaseIntensity);
        parameters["BloomSaturation"].SetValue(Settings.BloomSaturation);
        parameters["BaseSaturation"].SetValue(Settings.BaseSaturation);

        ScreenManager.GraphicsDevice.Textures[1] = sceneRenderTarget;

        Viewport viewport = ScreenManager.GraphicsDevice.Viewport;

        DrawFullscreenQuad(renderTarget1,
                           viewport.Width, viewport.Height,
                           bloomCombineEffect,
                           IntermediateBuffer.FinalResult);

        #endregion

        spriteBatch.Begin();
        // Draw HUD
        spriteBatch.End();


        if (screenShotTake)
        {
            using (FileStream fs = File.Open(@"screenshot" + (screenshotNumber) + @".png", FileMode.OpenOrCreate))
            {
                // Right here I try to save out the screen shot Texture2D
                sceneRenderTarget.SaveAsPng(fs, (int)viewportSize.X, (int)viewportSize.Y); // save render target to disk
            }
        }
    }




    #region PostProcess & Bloom
    void DrawFullscreenQuad(Texture2D texture, RenderTarget2D renderTarget,
                            Effect effect, IntermediateBuffer currentBuffer)
    {
        ScreenManager.GraphicsDevice.SetRenderTarget(renderTarget);

        DrawFullscreenQuad(texture,
                           renderTarget.Width, renderTarget.Height,
                           effect, currentBuffer);


    }

    void DrawFullscreenQuad(Texture2D texture, int width, int height,
                            Effect effect, IntermediateBuffer currentBuffer)
    {
        if (showBuffer < currentBuffer)
        {
            effect = null;
        }

        spriteBatch.Begin(0, BlendState.Opaque, null, null, null, effect);
        spriteBatch.Draw(texture, new Rectangle(0, 0, width, height), Color.White);
        spriteBatch.End();
    }

}

Answer 1

问题出在这里:

ScreenManager.GraphicsDevice.SetRenderTarget(null);

由于这一行,您将效果绘制到后台缓冲区,但您保存的渲染目标将保持不变.您可以看到效果的结果,因为它是直接绘制的,但是您保存的不是您向后缓冲区绘制的内容.要解决此问题,请将效果绘制到另一个RenderTarget,然后将其作为单个纹理绘制到后台缓冲区.显然这是对流程的另一种吸引力,但这是一个最小的成本.通过这样做,您可以从新的RenderTarget中获取纹理,并根据需要保存它.