RECEIPT RACER
a microproject by undef and Joshua Noble

The receipt racer combines different in and output devices into a complete game. It was made during the "Let's feed the future workshop", organized by creativeapplications.net as a part of the OFFF Festival in Barcelona on June 8th 2011.

The game is played on a receipt printer, a common device you can see at every convenient store. It prints those papers you usually find crumbled up in your pockets, just to throw them away. It is a thermal printer using heat to darken the paper. This eliminates any slowdowns in printing lots of black. A roll can be ordered online and costs around 80 cents.

50 meters is the maximum distance you are theoretically able to race in one run, before running out of paper. So ecologically it's pretty much a disaster, just like any real car.

Print is a static medium. that's why it was an intriguing challenge to create an interactive game with it. First we tried to do it only with the printer as the visual representation but that seemed rather impossible. But then Joshua Noble came up with this tiny beamer, perfect to project a car onto a preprinted road.

There is no game without an input device. So we were lucky each of us always carries a gamepad around. We use them a lot because

they're physical and you can control something without have to look at it. And it is a game after all, so a joypad is the perfect match.

The cables come together on a laptop running an openframeworks application all three of us wrote parts of. The app was entirely programmed during the workshop. Internally it runs something like the basic js game. Onnly a car driving on a randomly generated race track. Then it broadcasts its components to the external devices, prints the street and guesses where the car's projection is supposed to be to perform the hit test. That's the trickiest part. Everything has to be in sync and needs some calibration in the beginning. The paper also has a

little bit of a mind of it's own and tends to slide around or curl. But that's nothing some duct tape and cardboard can't fix.

It was a lucky day. Somehow everything was just lying around, waiting to be used. Even the stand and this plastic thing you would normally use to put in your name on a conference. Even the timing was perfect. Right at the end of the workshop we finished adding the details like a little score and the YOU CRASHED TEXTS. Components that make it a complete game. It was a great experience and we thank creativeapplications.net to provide this platform and gathering all these people in one room for a whole day.

You can download the source code and a compiled mac version here: receiptRacer. It should compile on other systems as well. But beware! It was a one day project, so it's quite a mess...

[undef June 12th 2011]