We've all played some kind of 3D game at one point in our lives, so I think we are all on the same page already.

I'm considering attempting to develop a First-Person Shooter game (That's right, not in BYOND -- *gasp*). I've been curious for a long time about how exactly these 3D engines work (E.g. displaying walls and floors at the correct angles), but I haven't been able to locate any sites on the topic. I was wondering if anyone knew of any decent resources on how this is done. Not how it is done code-wise, but just generally how they work.
There's a book I used to own call the Black Art of 3D Game Programming, which is quite dated now, but may hold the info you seek. It was very well written, and had some basic games with C++ code to boot. Recomended reading.