By now, everyone’s seen the viral video of the world’s largest game of tetris that was played on the side of a Philadelphia skyscraper. Fast Company has a post on how one Drexel gaming professor pulled it off.

It all started with a hallucination. As anybody who has spent some fraction of his or her life glued to Tetris knows, the game’s pieces have a way of showing up in the real world. This so-called Tetris Effect is a real thing, as Dr. Frank Lee experienced one day as he drove by the Philadelphia skyline and imagined Tetris shapes falling down the side of a skyscraper. It made him wonder: Could you hack a building and turn it into a giant video game?

Apparently you can. Lee, who co-founded the game design program at Drexel University, unveiled a skyscraper-sized version of Tetris this weekend as part of Philly Tech Week. For two nights, players took over opposite sides of the 29-story Cira Centre, a massive building whose LED-covered facade was commandeered by Lee and his team to create the game.

With an estimated 2,000 attendees, Saturday’s event was a hit, which you’d expect from something involving Tetris, food trucks, and beer. Indeed, the very concept of Tetris being played on a skyscraper was enough to attract national press coverage, including a roundup of animated GIFs. It also happened to coincide with the 30th anniversary of the game’s launch; Tetris Company co-founder Henk Rogers was there to mark the occasion…

HOW IT WORKS

The Cira Centre’s exterior is affixed with Philips Color Kinetics LED lights (the same kind adorning the Bay Bridge), which means that they’re Internet-connected. For Lee’s team, the first step was gaining access to the network that controls the lights.

Lee’s team solicited the owner of the building for several teams to get direct VPN access to the network. Once the owner supplied the code, Lee’s team mapped the physical location of each light and parsed them together into a grid so they could map the lights to pixels from the homegrown version of Pong they created. Luckily for them, somebody on GitHub had already written software to take control of lighting systems, which made their work considerably easier.

“At that point, I knew it was theoretically possible,” Lee says. “If you can control the pixels, you can create a game.”

Like Pong before it, the larger-than-life Tetris game is controlled by joysticks connected to laptops that send keystrokes over a 4G wireless hotspot to a server inside the Cira Centre network. These signals tell the system which LED lights to illuminate and when. The result is a crudely simple, yet fluid, animation of pixels that’s akin to an early Atari game, complete with sound effects.

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