OpenGL 渲染导致图形故障

Question

代码如下。当程序运行时，它会生成或多或少正确的图像，但存在一些图形故障。以下是一些图片：。关于可能导致此问题的任何想法？最奇怪的部分是问题似乎是在三角形上形成的，即使图像是用多边形（四边形）绘制的。

void buildList() {
    cubelist = glGenLists(1);
    glNewList(cubelist,GL_COMPILE);

    // Multi-colored side - FRONT
    glBegin(GL_POLYGON);
    glColor3b(0,0,0);
    glVertex3f( -0.5, -0.5, -0.5);
    glVertex3f( -0.5,  0.5, -0.5);
    glVertex3f(  0.5,  0.5, -0.5);
    glVertex3f(  0.5, -0.5, -0.5);
    // Black side - BACK
    glBegin(GL_POLYGON);
    glColor3b(0,0,0);
    glVertex3f(  0.5, -0.5, 0.5 );
    glVertex3f(  0.5,  0.5, 0.5 );
    glVertex3f( -0.5,  0.5, 0.5 );
    glVertex3f( -0.5, -0.5, 0.5 );
    glEnd();

    // Purple side - RIGHT
    glBegin(GL_POLYGON);
    glColor3f(  1.0,  0.0,  1.0 );
    glVertex3f( 0.5, -0.5, -0.5 );
    glVertex3f( 0.5,  0.5, -0.5 );
    glVertex3f( 0.5,  0.5,  0.5 );
    glVertex3f( 0.5, -0.5,  0.5 );
    glEnd();

    // Green side - LEFT
    glBegin(GL_POLYGON);
    glColor3f(   0.0,  1.0,  0.0 );
    glVertex3f( -0.5, -0.5,  0.5 );
    glVertex3f( -0.5,  0.5,  0.5 );
    glVertex3f( -0.5,  0.5, -0.5 );
    glVertex3f( -0.5, -0.5, -0.5 );
    glEnd();

    // Blue side - TOP
    glBegin(GL_POLYGON);
    glColor3f(   0.0,  0.0,  1.0 );
    glVertex3f(  0.5,  0.5,  0.5 );
    glVertex3f(  0.5,  0.5, -0.5 );
    glVertex3f( -0.5,  0.5, -0.5 );
    glVertex3f( -0.5,  0.5,  0.5 );
    glEnd();

    // Red side - BOTTOM
    glBegin(GL_POLYGON);
    glColor3f(   1.0,  0.0,  0.0 );
    glVertex3f(  0.5, -0.5, -0.5 );
    glVertex3f(  0.5, -0.5,  0.5 );
    glVertex3f( -0.5, -0.5,  0.5 );
    glVertex3f( -0.5, -0.5, -0.5 );
    glEnd();
    glEndList();
}

void setupGL() {
    glClearColor(1, 1, 1, 0);
    glEnable(GL_DEPTH_CLAMP);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
    glCullFace(GL_FRONT_AND_BACK);
}

int main(int, char const**)
{
    sf::Window window(sf::VideoMode(1600, 1200), "OpenGL", sf::Style::Default, sf::ContextSettings(32));
    window.setVerticalSyncEnabled(true);
    //initWorld();
    setupGL();
    buildList();

    while (running)
    {

        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        // Process events
        sf::Event event;
        handleInput(window);
        while (window.pollEvent(event))
        {
            // Close window: exit
            if (event.type == sf::Event::Closed) {
                running = false;
            }

            // Escape pressed: exit
            if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Escape) {
                running = false;
            }
        }

        glCallList(cubelist);

        // Update the window (c is a "Camera" object that just sets the perspective.   I can provide code if necessary)
        c.draw();
        window.display();
    }

    return EXIT_SUCCESS;
}

编辑：因此将 GL_POLYGONS 语句更改为 GL_QUADS 似乎可以解决问题，但我仍然对原因有些好奇。

Answer 1

您的第一个 glBegin 没有匹配的 glEnd，这会导致在下一个 glEnd 之前忽略所有其他 glBegin。这意味着正面泄漏到背面。

即刻模式和相关的 displayList 已弃用，而是查看 VBO 来存储顶点数据。

OpenGL 渲染导致图形故障

OpenGL rendering causes graphical glitch

opengl

3d

graphics

sfml

immediate-mode