延迟着色天空盒，在全屏四边形后渲染
Deferred shading skybox, rendered after full screen quad
因此，作为延迟着色器的最后一步，我一直在尝试让天空盒工作。本质上，我经历了所有常规的延迟着色器步骤，然后使用一些 post 处理东西，如 HDR 和 bloom，最后一步使用前向着色器渲染到全屏四边形。现在，如果我只是单独渲染天空盒或延迟着色结果，一切看起来都正常。当我最后尝试渲染天空盒时，它并没有出现在屏幕上。
所以基本上在我用结果渲染四边形之后，我想使用几何通道的深度值渲染天空盒。我已经尝试按照 的建议 blitting 深度缓冲区，但它没有任何效果，我认为问题在于我如何为 FBO 设置深度缓冲区，因为它共享一个模板附件。
我对天空盒的渲染调用：
//draw skybox
glEnable(GL_DEPTH_TEST);
glBindFramebuffer(GL_READ_FRAMEBUFFER, mFBO);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
glBlitFramebuffer(0, 0, mWindowWidth, mWindowHeight, 0, 0, mWindowWidth, mWindowHeight, GL_DEPTH_BUFFER_BIT, GL_NEAREST);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// Draw skybox as last
glDepthFunc(GL_LEQUAL); // Change depth function so depth test passes when values are equal to depth buffer's content
ShaderMan.bindShader(SKY_BOX_SHADER);
glm::mat4 view = glm::mat4(glm::mat3(CameraMan.getActiveCamera()->getViewMatrix())); // Remove any translation component of the view matrix
glm::mat4 projection = CameraMan.getActiveCamera()->getProjectionMatrix();
glUniformMatrix4fv(ShaderMan.getActiveShader().getUniformLocation("viewMatrix"), 1, GL_FALSE, glm::value_ptr(view));
glUniformMatrix4fv(ShaderMan.getActiveShader().getUniformLocation("projectionMatrix"), 1, GL_FALSE, glm::value_ptr(projection));
// skybox cube
glUniform1i(ShaderMan.getActiveShader().getUniformLocation("skybox"), 0);
mSkybox.render();
glDepthFunc(GL_LESS); // Set depth function back to default
ShaderMan.unbindShader();
以及我如何设置延迟的 FBO
//POSIITON
glGenTextures(1, &mPositionTexture);
glBindTexture(GL_TEXTURE_2D, mPositionTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F, mWindowWidth, mWindowHeight, 0, GL_RGB, GL_FLOAT, NULL);
//Nearest min mag filters since we dont want interpolated values
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
//glFrameBuffer attaches a texture as a color attachment, depth attachment or stencil etc
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mPositionTexture, 0);
glGenTextures(1, &mNormalTexture);
glBindTexture(GL_TEXTURE_2D, mNormalTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F, mWindowWidth, mWindowHeight, 0, GL_RGB, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, mNormalTexture, 0);
//Combined color and specular buffer
glGenTextures(1, &mSpecularAlbedoTexture);
glBindTexture(GL_TEXTURE_2D, mSpecularAlbedoTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F, mWindowWidth, mWindowHeight, 0, GL_RGBA, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, GL_TEXTURE_2D, mSpecularAlbedoTexture, 0);
//Depth & stencil texture for the FBO
glGenTextures(1, &mDepthTexture);
glBindTexture(GL_TEXTURE_2D, mDepthTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH32F_STENCIL8, mWindowWidth, mWindowHeight, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_TEXTURE_2D, mDepthTexture, 0);
// final
glGenTextures(1, &mFinalTexture);
glBindTexture(GL_TEXTURE_2D, mFinalTexture);
///Used to be GL_RGBA only
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, mWindowWidth, mWindowHeight, 0, GL_RGB, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT4, GL_TEXTURE_2D, mFinalTexture, 0);
我认为 GL_DEPTH_STENCIL_ATTACHMENT 是什么东西搞砸了，但我也不明白为什么如果你在 blit 函数中指定它，你不应该能够 blit 深度附件
结果图像，无天空盒：result
编辑
我尝试搜索了一下并将格式更改为 GL_DEPTH_24_STENCIL8 以防主 fbo 具有不同的 float 格式，但这也无济于事。
您不应尝试将 FBO 深度缓冲区 blit 到默认深度缓冲区。要从一个深度缓冲区 blit 到另一个深度缓冲区，两者的内部格式必须完全相同。虽然您可以定义 FBO 的格式，但默认深度缓冲区是实现定义的。您可能能够通过反复试验推断出其格式，但解决方案将不可移植。
一个解决方案是在几何过程中将你的深度写入 R32F 纹理颜色附件。稍后当您将天空盒绘制到默认帧缓冲区时，您可以将 R32F 纹理绑定到采样器并在片段着色器中读取该像素的深度。只输出天空盒到深度为0.0f的片段。
因此，作为延迟着色器的最后一步，我一直在尝试让天空盒工作。本质上，我经历了所有常规的延迟着色器步骤，然后使用一些 post 处理东西，如 HDR 和 bloom，最后一步使用前向着色器渲染到全屏四边形。现在，如果我只是单独渲染天空盒或延迟着色结果，一切看起来都正常。当我最后尝试渲染天空盒时，它并没有出现在屏幕上。
所以基本上在我用结果渲染四边形之后，我想使用几何通道的深度值渲染天空盒。我已经尝试按照
我对天空盒的渲染调用：
//draw skybox
glEnable(GL_DEPTH_TEST);
glBindFramebuffer(GL_READ_FRAMEBUFFER, mFBO);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
glBlitFramebuffer(0, 0, mWindowWidth, mWindowHeight, 0, 0, mWindowWidth, mWindowHeight, GL_DEPTH_BUFFER_BIT, GL_NEAREST);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// Draw skybox as last
glDepthFunc(GL_LEQUAL); // Change depth function so depth test passes when values are equal to depth buffer's content
ShaderMan.bindShader(SKY_BOX_SHADER);
glm::mat4 view = glm::mat4(glm::mat3(CameraMan.getActiveCamera()->getViewMatrix())); // Remove any translation component of the view matrix
glm::mat4 projection = CameraMan.getActiveCamera()->getProjectionMatrix();
glUniformMatrix4fv(ShaderMan.getActiveShader().getUniformLocation("viewMatrix"), 1, GL_FALSE, glm::value_ptr(view));
glUniformMatrix4fv(ShaderMan.getActiveShader().getUniformLocation("projectionMatrix"), 1, GL_FALSE, glm::value_ptr(projection));
// skybox cube
glUniform1i(ShaderMan.getActiveShader().getUniformLocation("skybox"), 0);
mSkybox.render();
glDepthFunc(GL_LESS); // Set depth function back to default
ShaderMan.unbindShader();
以及我如何设置延迟的 FBO
//POSIITON
glGenTextures(1, &mPositionTexture);
glBindTexture(GL_TEXTURE_2D, mPositionTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F, mWindowWidth, mWindowHeight, 0, GL_RGB, GL_FLOAT, NULL);
//Nearest min mag filters since we dont want interpolated values
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
//glFrameBuffer attaches a texture as a color attachment, depth attachment or stencil etc
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mPositionTexture, 0);
glGenTextures(1, &mNormalTexture);
glBindTexture(GL_TEXTURE_2D, mNormalTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F, mWindowWidth, mWindowHeight, 0, GL_RGB, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, mNormalTexture, 0);
//Combined color and specular buffer
glGenTextures(1, &mSpecularAlbedoTexture);
glBindTexture(GL_TEXTURE_2D, mSpecularAlbedoTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F, mWindowWidth, mWindowHeight, 0, GL_RGBA, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, GL_TEXTURE_2D, mSpecularAlbedoTexture, 0);
//Depth & stencil texture for the FBO
glGenTextures(1, &mDepthTexture);
glBindTexture(GL_TEXTURE_2D, mDepthTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH32F_STENCIL8, mWindowWidth, mWindowHeight, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_TEXTURE_2D, mDepthTexture, 0);
// final
glGenTextures(1, &mFinalTexture);
glBindTexture(GL_TEXTURE_2D, mFinalTexture);
///Used to be GL_RGBA only
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, mWindowWidth, mWindowHeight, 0, GL_RGB, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT4, GL_TEXTURE_2D, mFinalTexture, 0);
我认为 GL_DEPTH_STENCIL_ATTACHMENT 是什么东西搞砸了，但我也不明白为什么如果你在 blit 函数中指定它，你不应该能够 blit 深度附件
结果图像，无天空盒：result
编辑
我尝试搜索了一下并将格式更改为 GL_DEPTH_24_STENCIL8 以防主 fbo 具有不同的 float 格式，但这也无济于事。
您不应尝试将 FBO 深度缓冲区 blit 到默认深度缓冲区。要从一个深度缓冲区 blit 到另一个深度缓冲区，两者的内部格式必须完全相同。虽然您可以定义 FBO 的格式，但默认深度缓冲区是实现定义的。您可能能够通过反复试验推断出其格式，但解决方案将不可移植。
一个解决方案是在几何过程中将你的深度写入 R32F 纹理颜色附件。稍后当您将天空盒绘制到默认帧缓冲区时，您可以将 R32F 纹理绑定到采样器并在片段着色器中读取该像素的深度。只输出天空盒到深度为0.0f的片段。