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.
A year earlier, Lee used the structure to display a playable version of Pong. The project won the Guinness World Record for being the largest architectural video game display ever created.
"I was less interested in the fact that we had this 29-story version of Pong and more that it was visible by the entire city," Lee says. "As two people stood and played Pong, there were a few hundred people watching at the Philadelphia Museum of Art. Beyond that, there were potentially thousands of people across the city of Philadelphia sharing in that moment."
With Tetris, Lee would not only return to his original vision for skyscraper gaming, but could expand this collective experience across a wider geographic swath of the city. Whereas Pong was visible on the north side of the Cira Centre, Tetris would occupy opposite sides of the building, with players located across the city from one another.
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.
Several blocks away from the building and on either side (most were just over the river in front of the Philadelphia Museum of Art), participants lined up to play their invisible opponents in a series of Tetris duels--imagine the single-screen competitive version of Tetris found in arcades, but with rows of blocks lining up on opposite sides of a building rather than side-by-side on a screen. Then imagine playing the game surrounded by dozens of onlookers and the collective sighs, grunts, and cheering--not to mention the group humming the original Tetris theme song. That's what Saturday and Sunday nights were like.
As you might imagine, designing a video game to display on a skyscraper is not without its challenges. Thankfully for Lee, last year's Pong installation served as a sort of dry run--it was still a big deal, but it had fewer pixels, fewer players, and fewer observers.
"Pong was fairly easy, because given the resolution, we knew that it could be done and it would look good," says Lee. "We didn't know how Tetris would look. If you look at our shapes, they're almost double the size of normal Tetris shapes, so they look good at 20x20 pixels."
Other details--such as the exact color of the some of the shapes--were constrained by the limitations of the lights and by the building itself. The Cira Centre is a pretty weird structure. With its reflective exterior and asymmetrical shape, the 437-foot-high building resembles a magic crystal jutting out into the sky. It happens to be very wide and adorned with LED lights, but beyond that, its design is not particularly forgiving to game designers.
"Even the vertical edges of the building don't come down straight," says Lee. "They go inwards or outwards depending on the edge. The south side is also slightly narrower. So we had to figure out the maximum size we could use between the two sides. That dropped us to playable area of 18 x 23 pixels."
The building's awkward shape also made it difficult to design competitive feedback into the game. With players standing more than a mile apart and unable to track one another's progress, there was no obvious way to clue players into the status of their competitors. Lee initially wanted to give each player a live video feed of their opponent's screen, but doing so would eat up precious wireless bandwidth needed to send keystrokes and game play data to and from the building's network.
"The solution was to create a feedback mechanism by taking a vertical line that we weren’t using on the north side, and use one of the columns of lights to track the height of the highest point of the opposing player," Lee explains. Since the south side of the building isn't symmetrical, they had to squeeze this feedback onto the southwest corner of the building in a way that would be visible to the players on that side.
Anyone who works in interactive design knows the tedium of designing for different devices, screens, and resolutions. And while designing for only one display does simplify things, it doesn't help if that display isn't a screen so much as a place where people go to work. For Lee and his team, that meant that they couldn't always trust the laptop-based simulator they used to develop the game.
"It was a challenge to see it working perfectly on our simulator and then finding out that it looks crappy on the building," says Lee. "After a lot of simulation work, it was an iteration of test, test, and more test. And let me tell you, it’s not easy to debug something when your display is two opposite sides of a building."
And things like external lighting conditions and the weather matter a great deal. Where you're standing is also important. At a VIP event at Drexel on Sunday night, a select group of people got to play the game from a terrace with a view of the Cira Centre that was more direct, their view was obscured ever so slightly by the reflection of lights from an adjacent skyscraper. It's a minor detail, but one that is unique to the task of turning an urban environment into a giant arcade.
"I think the design lesson that I took away was that while you should respect the constraints that one is given, there are always creative ways to overcome those constraints if you just step back and give yourself some time to actually think things through," says Lee.