多重采样 FBO 忽略深度测试

Multisampled FBO is ignoring depth testing

我修改了我的渲染引擎以使用多重采样纹理,除了现在忽略深度测试。

下面是我创建多重采样 FBO 的方法,

public MSAA_FBO(int WindowWidth, int WindowHeight)
{
    this.width = WindowWidth;
    this.height = WindowHeight;

    GL.GenFramebuffers(1, out ID);
    GL.BindFramebuffer(FramebufferTarget.Framebuffer, ID);

    // Colour texture
    GL.GenTextures(1, out textureColorBufferMultiSampled);
    GL.BindTexture(TextureTarget.Texture2DMultisample, textureColorBufferMultiSampled);
    GL.TexImage2DMultisample(TextureTargetMultisample.Texture2DMultisample, 4, PixelInternalFormat.Rgb8, WindowWidth, WindowHeight, true);
    GL.FramebufferTexture2D(FramebufferTarget.Framebuffer, FramebufferAttachment.ColorAttachment0, TextureTarget.Texture2DMultisample, textureColorBufferMultiSampled, 0);

    // Depth render buffer
    GL.GenRenderbuffers(1, out RBO);
    GL.BindRenderbuffer(RenderbufferTarget.RenderbufferExt, RBO);
    GL.RenderbufferStorageMultisample(RenderbufferTarget.Renderbuffer, 4, RenderbufferStorage.DepthComponent, WindowWidth, WindowHeight);
    GL.BindRenderbuffer(RenderbufferTarget.Renderbuffer, 0);

    var status = GL.CheckFramebufferStatus(FramebufferTarget.Framebuffer);
    Console.WriteLine("MSAA: " + status);
    GL.BindFramebuffer(FramebufferTarget.Framebuffer, 0);
}      

执行解析,

public void resolveToFBO(FBO outputFBO)
{
    GL.BindFramebuffer(FramebufferTarget.DrawFramebuffer, outputFBO.ID);
    GL.BindFramebuffer(FramebufferTarget.ReadFramebuffer, this.ID);
    GL.BlitFramebuffer(0, 0, this.width, this.height, 0, 0, outputFBO.width, outputFBO.height, ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit, BlitFramebufferFilter.Nearest);     
}

并渲染图像,

public void MSAAPass(Shader shader)
{
    GL.UseProgram(shader.ID);
    GL.BindFramebuffer(FramebufferTarget.Framebuffer, MSAAbuffer.ID);
    GL.Viewport(0, 0, Width, Height);

    GL.Enable(EnableCap.Multisample);
    GL.ClearColor(System.Drawing.Color.Black);
    GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
    GL.Enable(EnableCap.DepthTest);
    GL.Disable(EnableCap.Blend);

    // Uniforms
    Matrix4 viewMatrix = player.GetViewMatrix();
    GL.UniformMatrix4(shader.getUniformID("viewMatrix"), false, ref viewMatrix);

    // Draw all geometry
    DrawScene(shader);

    GL.BindFramebuffer(FramebufferTarget.Framebuffer, 0);
    MSAAbuffer.resolveToFBO(testBuffer);
}

您的多重采样 FBO 没有深度缓冲区,因此深度测试将不起作用。虽然您实际上创建了一个 GL_DEPTH_COMPONENT 格式的多重采样渲染缓冲区,但您忘记将其附加为 FBO 的 GL_DEPTH_ATTACHMENT。您需要在 MSAA_FBO() 函数中添加一个 glFramebufferRenderbuffer() 调用。