3D graphics

[Matthew A Machlis]

I know this is a simple question, but...

I wrote a small c program which draws a cube with 2 opposing sides
removed to make it "hollow," and which lets you move around inside
the cube.  I use "makeobj()" to define the cube and "polf()" to
draw each face.  It looks correct from one side, but when you look
at it from the opposite side, the computer still draws the faces
in the same order of overlap, so it does not look right.  Does this
have something to do with zbuffering?  I'm using a 3020, by the
way.  Any help would be appreciated.