Have you played the classic FPSs like DOOM and Wolfestein? Do you want to know how they did it? They did it using a technique called raycasting!
This, of course, isn't a completely fair statement, they also had some damn clever design! Raycasting, is however how they achieved their games. It is a way of getting a 3D-like effect on hardware that really isn't capable of 3D. I mean, DOOM is available on anything from the SNES to modern Windows(albeit through DOSBox).
Sure, knowing the technique isn't going to mean your game instanly is a hit. It would even be a stretch to say it has any practical application, yet it remains as an interesting artifact to times long gone.
If you want more information on raycasting's limits and how to do it, feel free to read the documentation available for download below.
Click download now to get access to the following files: