OpenGL只显示2个四边形

Question

我正在尝试在openGL中创建一个房间，但我有以下四边形但是wall2和wall4没有显示。我猜这与透视有关，好像我走出房间，我可以看到它们已被渲染。

glColor3f(0.1f, 0.9f, 0.9f);
//Wall1
glBegin(GL_QUADS);
glNormal3f(0,0,1);
glVertex3f(-10,0,-10);
glVertex3f( 10,0,-10);
glVertex3f( 10,5,-10);
glVertex3f(-10,5,-10);
glEnd();

//Wall2
glColor3f(1.0f, 1.0f, 1.0f);
glBegin(GL_QUADS);
glNormal3f(0,0,1);
glVertex3f(-10,0, 10);
glVertex3f( 10,0, 10);
glVertex3f( 10,5, 10);
glVertex3f(-10,5, 10);
glEnd();

//Wall3
glColor3f(0.4f, 0.9f, 0.1f);
glBegin(GL_QUADS);
glNormal3f(-1,0, 0);
glVertex3f( 10,0,-10);
glVertex3f( 10,0,10);
glVertex3f( 10,5,10);
glVertex3f( 10,5,-10);
glEnd();

//Wall4
glColor3f(0.1f, 0.2f, 0.2f);
glBegin(GL_QUADS);
glNormal3f(1, 0, 0);
glVertex3f( -10,0,-10);
glVertex3f( -10,0,10);
glVertex3f( -10,5,10);
glVertex3f( -10,5,-10);
glEnd();

Answer 1

尝试禁用脸部剔除！ ：）