OpenGL场景居中问题

Question

我正在尝试制作一个场景，让我看着 XY 平面，Z 朝向和远离相机视图。我想看到比我面前的对象更远且大小不同的对象，所以我想我应该为此使用 gluPerspective。我的屏幕上应该有一些轴来自原点，但是，我什么都看不到。我让它与一堆翻译一起工作，但我想确保我理解如何正确操作它，因为这都是猜测和检查。

void resizeWindow(GLint newWidth, GLint newHeight)
{
    glViewport(0, 0, newWidth, newHeight);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(60.0f, (GLfloat)newWidth / (GLfloat)newHeight, 0.1f, 100.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    gluLookAt(0.0, 0.0, -1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
}

glPushMatrix();
glColor4ub(0, 120, 20, 255);
glBegin(GL_LINE_STRIP);
glVertex3f(0.0f, 0.0f, 0.0f);
glVertex3f(3.0f, 0.0f, 0.0f);
glVertex3f(2.85f, 0.10f, 0.0f);
glVertex3f(2.85f, -0.10f, 0.0f);
glVertex3f(3.0f, 0.0f, 0.0f);
glVertex3f(2.85f, 0.0f, 0.10f);
glVertex3f(2.85f, 0.0f, -0.10f);
glVertex3f(3.0f, 0.0f, 0.0f);
glEnd();
glBegin(GL_LINE_STRIP);
glVertex3f(0.0f, 0.0f, 0.0f);
glVertex3f(0.0f, 3.0f, 0.0f);
glVertex3f(0.0f, 2.85f, 0.10f);
glVertex3f(0.0f, 2.85f, -0.10f);
glVertex3f(0.0f, 3.0f, 0.0f);
glVertex3f(0.10f, 2.85f, 0.0f);
glVertex3f(-0.10f, 2.85f, 0.0f);
glVertex3f(0.0f, 3.0f, 0.0f);
glEnd();
glBegin(GL_LINE_STRIP);
glVertex3f(0.0f, 0.0f, 0.0f);
glVertex3f(0.0f, 0.0f, 3.0f);
glVertex3f(0.10f, 0.0f, 2.85f);
glVertex3f(-0.10f, 0.0f, 2.85f);
glVertex3f(0.0f, 0.0f, 3.0f);
glVertex3f(0.0f, 0.10f, 2.85f);
glVertex3f(0.0f, -0.10f, 2.85f);
glVertex3f(0.0f, 0.0f, 3.0f);
glEnd();

Answer 1

没有尝试运行代码，而是快速浏览了一下：

• 删除 glPushMatrix()。你不会在任何地方弹出它......也不会修改它们
• 您的“眼睛”坐标（0.0、0.0、-1.0）似乎有点太接近原始坐标了，因为您的轴长度为 3.0 单位。试试 (0.0, 0.0, -20.0) 左右。