Модели заходят друг на друга. Как исправить? Python

from OpenGL.GLU import *
from OpenGL.GL import *
import pygame
from pygame.locals import *
 
size_display = (230*4, 230 * 3)
 
pygame.init()
pygame.display.set_mode(size_display, DOUBLEBUF|OPENGL)
pygame.display.set_caption("SQUARE 3D")
gluPerspective(45, (size_display[0] / size_display[1]), 0.1, 50.0, )
glTranslatef(0.0, 0.0, -10)
 
 
def Square():
    glBegin(GL_QUADS)
 
    glColor3f(0.6, 4.0, 0.0)
 
    glVertex3f(0, 1, 0)
    glVertex3f(0, 0, 0)
    glVertex3f(1, 0, 0)
    glVertex3f(1, 1, 0)
 
    glColor3f(0.0, 0.3, 1.0)
 
    glVertex3f(0, 1, 1)
    glVertex3f(0, 0, 1)
    glVertex3f(1, 0, 1)
    glVertex3f(1, 1, 1)
 
    glColor3f(0.7, 0.0, 1.0)
 
 
    glEnd()
 
 
while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            quit()
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    Square()
    glRotatef(1, 1, 0, 0)
    pygame.display.flip()
    pygame.time.wait(10)