Question

啊哈！看来我的问题是我给gluPerspective的zNear值必须大于0，我必须启用深度缓冲来使它工作。我已经更新了以下代码以便工作。

我已经尝试过这么做了，并且一直以为我是以错误的顺序定义我的四边形顶点，但是现在，我知道它的其他东西。

我尝试过启用Culling，将frontFace更改为顺时针，禁用混合，添加法线，但我总是得到一个看起来像这样的立方体;

what the cube looks like

希望您甚至不必查看我的代码就知道问题是什么，因为这样做并不太难。

如果您不立即知道问题所在，这里是用于设置和绘制多维数据集的代码。

// FIXED CODE.
// reshape, called on init, and window resize
void reshape(int w, int h) {
     scrw=w;
     scrh=h;
     glClearColor(0.8,0.8,0.8,1.0);
     glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
     gluPerspective(cfov,(float) scrw/ (float) scrh,1,1000); // this is also a part of the fix.
     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();
     glEnable(GL_BLEND);
     glEnable(GL_DEPTH_TEST); // this is a part of the fix
     glEnable(GL_CULL_FACE);
     glCullFace(GL_FRONT);
     glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
     glViewport(0,0,scrw,scrh);
}
// drawQuadCube(), called every frame.
void drawQuadCube() {
     glPushMatrix();
     glTranslated(0.5,0.5,0.5);
     glRotated(xangle,0,1,0);
     glRotated(yangle,1,0,0);
     glRotated(zangle,0,0,1);
     glTranslated(-0.5,-0.5,-0.5);
     glBegin(GL_QUADS);
               //   bottom
               glColor4ub(30,30,255,255);
          glVertex3f(0.0f, 0.0f, 1.0f);
          glVertex3f(1.0f, 0.0f, 1.0f);
          glVertex3f(1.0f, 0.0f, 0.0f);
          glVertex3f(0.0f, 0.0f, 0.0f);
               //   top
               glColor4ub(40,40,255,255);
          glVertex3f(0.0f, 1.0f, 1.0f);
          glVertex3f(1.0f, 1.0f, 1.0f);
          glVertex3f(1.0f, 1.0f, 0.0f);
          glVertex3f(0.0f, 1.0f, 0.0f);
               //   left
               glColor4ub(60,60,255,255);
          glVertex3f(0.0f, 0.0f, 1.0f);
          glVertex3f(0.0f, 0.0f, 0.0f);
          glVertex3f(0.0f, 1.0f, 0.0f);
          glVertex3f(0.0f, 1.0f, 1.0f);
               //   right
               glColor4ub(60,60,200,255);
          glVertex3f(1.0f, 0.0f, 1.0f);
          glVertex3f(1.0f, 0.0f, 0.0f);
          glVertex3f(1.0f, 1.0f, 0.0f);
          glVertex3f(1.0f, 1.0f, 1.0f);
               //   near
               glColor4ub(70,70,100,255);
          glVertex3f(0.0f, 0.0f, 0.0f);
          glVertex3f(1.0f, 0.0f, 0.0f);
          glVertex3f(1.0f, 1.0f, 0.0f);
          glVertex3f(0.0f, 1.0f, 0.0f);
               //   far
               glColor4ub(20,20,90,255);
          glVertex3f(0.0f, 0.0f, 1.0f);
          glVertex3f(1.0f, 0.0f, 1.0f);
          glVertex3f(1.0f, 1.0f, 1.0f);
          glVertex3f(0.0f, 1.0f, 1.0f);
          glNormal3f(0,0,0);
          glNormal3f(0,0,1);
          glNormal3f(0,1,0);
          glNormal3f(1,0,0);
          glNormal3f(1,0,1);
          glNormal3f(1,1,0);
          glNormal3f(1,1,1);
          glNormal3f(0,1,1);
     glEnd();
     glPopMatrix();

}
// if that isn't enough, this is the function used to set up the view.
void setView(void) {
     glLoadIdentity();
     gluLookAt(0.5,0.5,-5,0.5,0.5,0.5,0,1,0);
}