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Editorial Team
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Asked: 2026-06-04T04:00:22+00:00

I’m trying to program a rotaing cube. Therefore I generate a cube using my

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I’m trying to program a rotaing cube. Therefore I generate a cube using my make_cube method. Unfortunatly some faces of the cube don’t get rendered. I tried a lot I don’t understand why the cube is not “extruded” fully. Here is my code for generating the cube:

def make_cube(self):
    glColor3f(0, 1, 0)
    #front
    GL.glVertex3d(0.0, 0.0, 0.0)
    GL.glVertex3d(0.2, 0.0, 0.0)
    GL.glVertex3d(0.2, 0.2, 0.0)
    GL.glVertex3d(0.0, 0.2, 0.0)
    # back
    GL.glVertex3d(0.0, 0.0, -0.2)
    GL.glVertex3d(0.2, 0.0, -0.2)
    GL.glVertex3d(0.2, 0.2, -0.2)
    GL.glVertex3d(0.0, 0.2, -0.2)
    # right
    GL.glVertex3d(0.2, 0.0, 0.0)
    GL.glVertex3d(0.2, 0.0, -0.2)
    GL.glVertex3d(0.2, 0.2, -0.2)
    GL.glVertex3d(0.2, 0.2, 0.0)
    # left
    GL.glVertex3d(0.0, 0.0, 0.0)
    GL.glVertex3d(0.0, 0.0, -0.2)
    GL.glVertex3d(0.0, 0.2, -0.2)
    GL.glVertex3d(0.0, 0.2, 0.0)
    # top
    GL.glVertex3d(0.0, 0.2, 0.0)
    GL.glVertex3d(0.2, 0.2, 0.0)
    GL.glVertex3d(0.2, 0.2, -0.2)
    GL.glVertex3d(0.0, 0.2, -0.2)
    # bottom
    GL.glVertex3d(0.0, 0.0, 0.0)
    GL.glVertex3d(0.2, 0.0, 0.0)
    GL.glVertex3d(0.2, 0.0, -0.2)
    GL.glVertex3d(0.0, 0.0, -0.2)
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1 Answer

  1. Editorial Team

    It is caused by culling. Your front and back side differs only in z component, that means one is rendered clock-wise another counter-cw and same for every else opposite sides.

    #front
GL.glVertex3d(0.0, 0.0, 0.0)
GL.glVertex3d(0.2, 0.0, 0.0)
GL.glVertex3d(0.2, 0.2, 0.0)
GL.glVertex3d(0.0, 0.2, 0.0)
# back
GL.glVertex3d(0.0, 0.0, -0.2)
GL.glVertex3d(0.2, 0.0, -0.2)
GL.glVertex3d(0.2, 0.2, -0.2)
GL.glVertex3d(0.0, 0.2, -0.2)

    OpenGL culls off back faces to improve perfomace, however you have to have all your primitives CW or CCW.

    Look at glCullFace and glFrontFace.

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