[In the second in this
series of articles which deconstructs a particularly fun or interesting
mechanic in a recent, relevant game, Jeremy Alessi pulls apart Valve's Portal and puts it back together again
-- to give us a clearer understanding of the compellingly-executed
teleportation mechanics central to that game's astoundingly entertaining
EDITOR'S NOTE: To download the
associated demo and code sample for Portal Demystified, please click here.
Welcome back to Games
Demystified. This month we'll be examining the chief gameplay mechanic behind
last year's amazing Portal! Anyone who's played Portal
has heard GLaDOS state, "Speedy thing goes in, speedy thing comes out".
That line sums up the
mechanics that distinguished Portal from the rest of the herd this past
winter. Sure, the impressive story and rendering also had a part, but it's simply
not a game without the mechanics.
Game mechanics are usually
abstractions based on real-world physics. In the previous Games Demystified
column, we covered gravity as it was applied in Super Mario Galaxy, a
force that is mostly unexplainable and yet tremendously fun with the proper
application in gameplay.
This go-round we're looking at wormholes,
Einstein-Rosen Bridges, or portals,
if you will. These phenomena are predicted by Einstein's theory of General
From Samuel Joseph George's description of The Einstein-Rosen Bridge
Like gravity, Einstein-Rosen
Bridges are mostly a mystery. Perhaps someday through imagination and cool video
games we'll gain a proper understanding. Until then, we've got a nice pseudo-laboratory
in Portal to experiment with these mechanics.
Just playing the game is a
mind-trip. Exactly how can we simulate a tunnel or wormhole through the fabric
of space-time? How do we do speedy-in, speedy-out, momentum redirection -- or "flinging",
as Valve calls it?
Teleport mechanics in video
games are nothing new. Puzzles from the original Gauntlet were memorable
-- and more than likely, that wasn't the first game to use teleportation as a
gameplay mechanic. The difference between Portal and all those that came
before it is that Portal's teleportation acts as a frictionless tube
between point A and point B.
Physics are still hard at
work inside the frictionless tube. Instead of simply repositioning an object
from point A to point B, the player enters point A with full velocity and exits
point B with the same speed, but moving in a new direction.