Question

我正在尝试在我的场景中使用SSAA。以前，我已将整个场景设置为FBO，并且工作正常（它在我的屏幕上呈现完美）。但是，一旦我尝试将SSAA应用到它，屏幕总是黑色的，我不确定为什么。我已经遵循了基于iOS的教程，但复制到可以找到here的窗口非常简单然而正如我在尝试使用类似技术时说的那样它不起作用。我理解SSAA的理论/概念，但似乎无法使其发挥作用。任何帮助我都非常感激，因为我找不到太多的材料（主要是MSAA或其他A.A.技术）

FBO初始化

void InitSSAAFBO()
{
    // Create the on-screen FBO.

    glGenFramebuffers(1, &fbo);
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER,
        GL_COLOR_ATTACHMENT0,
        GL_RENDERBUFFER,
        fboColTex);

    glGenRenderbuffers(1, &bigColour);
    glBindRenderbuffer(GL_RENDERBUFFER, bigColour);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8,
        windowWidth * supersamplingLevel, windowHeight * supersamplingLevel);

    glGenRenderbuffers(1, &bigDepth);
    glBindRenderbuffer(GL_RENDERBUFFER, bigDepth);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24,
        windowWidth * supersamplingLevel, windowHeight * supersamplingLevel);

    glGenFramebuffers(1, &fboBig);
    glBindFramebuffer(GL_FRAMEBUFFER, fboBig);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER,
        GL_COLOR_ATTACHMENT0,
        GL_RENDERBUFFER,
        bigColour);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER,
        GL_DEPTH_ATTACHMENT,
        GL_RENDERBUFFER,
        bigDepth);

    // Create a texture object and associate it with the big FBO.

    glGenTextures(1, &offscreenTexture);
    glBindTexture(GL_TEXTURE_2D, offscreenTexture);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, windowWidth * supersamplingLevel, windowHeight * supersamplingLevel, 0,
        GL_RGBA, GL_UNSIGNED_BYTE, 0);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
        GL_TEXTURE_2D, offscreenTexture, 0);

    GLenum demoFBOStatus = glCheckFramebufferStatus(GL_FRAMEBUFFER);

    if (demoFBOStatus != GL_FRAMEBUFFER_COMPLETE) {

        fboOkay = false;
        cout << "Could not successfully create framebuffer object to render texture!" << endl;

    }
    else {

        fboOkay = true;
        cout << "FBO successfully created" << endl;
    }

    // Unbind FBO for now! (Plug main framebuffer back in as rendering destination)
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

渲染

void display(void) {

    //Bind Large FBO
    glBindFramebuffer(GL_FRAMEBUFFER, fboBig);
    glBindRenderbuffer(GL_RENDERBUFFER, bigColour);
    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glViewport(0, 0, windowWidth * supersamplingLevel, windowHeight * supersamplingLevel);
    glEnable(GL_DEPTH_TEST);
    DrawScene();


    //Bind small/Onscreen FBO
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    glBindRenderbuffer(GL_RENDERBUFFER, fboColTex);

    glViewport(0, 0, windowWidth, windowHeight);
    glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    glDisable(GL_DEPTH_TEST);
    glUseProgram(fboShader);
    glBindVertexArray(quadVAO);
    glBindTexture(GL_TEXTURE_2D, offscreenTexture);
    glDrawArrays(GL_TRIANGLES, 0, 6);
    glBindVertexArray(0);

    glutSwapBuffers();
}

fboShader（顶点着色器）

#version 330 core
layout (location = 0) in vec2 position;
layout (location = 1) in vec2 texCoords;

out vec2 TexCoords;

void main()
{
    gl_Position = vec4(position.x, position.y, 0.0f, 1.0f); 
    TexCoords = texCoords;
}

fboShader（片段着色器）

#version 330 core
in vec2 TexCoords;
out vec4 color;

uniform sampler2D screenTexture;

void main()
{ 
    color = texture(screenTexture, TexCoords);
}

C ++ OpenGL尝试超级采样时没有渲染

0 个答案: