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Asked: 2026-05-25T11:32:00+00:00

I am pretty new to OpenGL and have run into a problem trying to

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I am pretty new to OpenGL and have run into a problem trying to render a skybox.
This picture illustrates the issue fairly well.

The sides of the skybox do not show up, and when I view an edge (like in the pic),
it just looks like the images are rendered right next to each other, instead of as
different sides of a cube.

void display ( void )   // Create The Display Function
{
glPushMatrix();
glDepthMask(0);
/* replace this code with your height field implementation */
/* you may also want to precede it with your rotation/translation/scaling */
/* Clear buffers */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
gluLookAt( 0.0, 0.0, 0.0,  // eye position
           0.1, 0.0, 0.1,  // camera direction
           0.0, 1.0, 0.0); // up direction

glPushAttrib(GL_ENABLE_BIT);
glEnable(GL_TEXTURE_2D);
glDisable(GL_DEPTH_TEST);
glDisable(GL_LIGHTING);
glDisable(GL_BLEND);

glColor4f(1.0, 1.0, 1.0, 1.0);

/*!!!!!!!!!!!!!! FRONT FACE !!!!!!!!!!!!!!!*/

glBindTexture(GL_TEXTURE_2D,frontTextureId); // select which texture to use
glBegin(GL_QUADS);
    glTexCoord2f(0, 0); glVertex3f(  0.5f,  0.5f, -0.5f );
    glTexCoord2f(1, 0); glVertex3f( -0.5f,  0.5f, -0.5f );
    glTexCoord2f(1, 1); glVertex3f( -0.5f, -0.5f, -0.5f );
    glTexCoord2f(0, 1); glVertex3f(  0.5f, -0.5f, -0.5f );
glEnd();

/*!!!!!!!!!!!!!! LEFT FACE !!!!!!!!!!!!!!!*/
glBindTexture(GL_TEXTURE_2D, leftTextureId); // select which texture to use
glBegin(GL_QUADS);
    glTexCoord2f(0, 0); glVertex3f(  0.5f,  0.5f,  0.5f );
    glTexCoord2f(1, 0); glVertex3f(  0.5f,  0.5f, -0.5f );
    glTexCoord2f(1, 1); glVertex3f(  0.5f, -0.5f, -0.5f );
    glTexCoord2f(0, 1); glVertex3f(  0.5f, -0.5f,  0.5f );
glEnd();

/*!!!!!!!!!!!!!! RIGHT FACE !!!!!!!!!!!!!!!*/
glBindTexture(GL_TEXTURE_2D, rightTextureId); // select which texture to use
glBegin(GL_QUADS);
    glTexCoord2f(0, 0); glVertex3f( -0.5f,  0.5f, -0.5f );
    glTexCoord2f(1, 0); glVertex3f( -0.5f,  0.5f,  0.5f );
    glTexCoord2f(1, 1); glVertex3f( -0.5f, -0.5f,  0.5f );
    glTexCoord2f(0, 1); glVertex3f( -0.5f, -0.5f, -0.5f );
glEnd();

/*!!!!!!!!!!!!!! BACK FACE !!!!!!!!!!!!!!!*/
glBindTexture(GL_TEXTURE_2D, backTextureId); // select which texture to use
glBegin(GL_QUADS);
    glTexCoord2f(0, 0); glVertex3f( -0.5f,  0.5f,  0.5f );
    glTexCoord2f(1, 0); glVertex3f(  0.5f,  0.5f,  0.5f );
    glTexCoord2f(1, 1); glVertex3f(  0.5f, -0.5f,  0.5f );
    glTexCoord2f(0, 1); glVertex3f( -0.5f, -0.5f,  0.5f );

glEnd();

/*!!!!!!!!!!!!!! TOP FACE !!!!!!!!!!!!!!!*/
glBindTexture(GL_TEXTURE_2D, upTextureId); // select which texture to use
glBegin(GL_QUADS);
    glTexCoord2f(0, 1); glVertex3f( -0.5f,  0.5f, -0.5f );
    glTexCoord2f(0, 0); glVertex3f( -0.5f,  0.5f,  0.5f );
    glTexCoord2f(1, 0); glVertex3f(  0.5f,  0.5f,  0.5f );
    glTexCoord2f(1, 1); glVertex3f(  0.5f,  0.5f, -0.5f );
glEnd();

/*!!!!!!!!!!!!!! BOTTOM FACE !!!!!!!!!!!!!!!*/
glBindTexture(GL_TEXTURE_2D, downTextureId); // select which texture to use
glBegin(GL_QUADS);
    glTexCoord2f(0, 0); glVertex3f( -0.5f, -0.5f, -0.5f );
    glTexCoord2f(0, 1); glVertex3f( -0.5f, -0.5f,  0.5f );
    glTexCoord2f(1, 1); glVertex3f(  0.5f, -0.5f,  0.5f );
    glTexCoord2f(1, 0); glVertex3f(  0.5f, -0.5f, -0.5f );
glEnd();

/*!!!!!!!!!!!!!! end of drawing of a textured quad !!!!!!!!!!!!!!!*/
glPopAttrib();
glPopMatrix();

/* Swap buffers, so one we just drew is displayed */
glutSwapBuffers();
}

I feel like I am missing something basic here, but I am not sure what. The code is
more or less verbatim from the tutorial site (http://sidvind.com/wiki/Skybox_tutorial).
The code was compiled with g++ 4.5.2 on Ubuntu Linux, but the same problem arises under
visual studio as well.

I should state, as well, that the numbers used in the code above are the values that
produced the linked picture.

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1 Answer

  1. Editorial Team

    Your textures need to form a seamless join across cube edges. In the screenshot you’ve supplied, these images don’t form a seamless join (look at the sky).

    Also check your projection matrix – are you setting a perspective transform?

    To set up a perspective projection (the most common for 3D apps):

    glMatrixMode(GL_PROJECTION);  // switch to projection matrix
glLoadIdentity();  // reset projection
gluPerspective(90.0,4.0/3.0,0.01,10.0);   // 90deg FOV, 4:3 aspect ratio, 0.01 near clip plane, 10.0 far clip plane
glMatrixMode(GL_MODELVIEW);  // back to model matrix
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