Two players sit across the table from each other. They grasp handles. They stare straight at each other through a darkened tunnel, their faces perfectly aligned. The handles are physically coupled: when one player moves his handle left, the other is forced to the left. As the handles move, a line appears in the air between the players' faces, tracking its movement, creating a drawing. Each player tries to trace the face of the other. Where their faces are symmetrical, and therefore aligned, the players agree on the drawing to create and collaborate. Where their faces differ, the players are forced to negotiate a strategy for eliding the differences or to compete for physical control of the drawing point.

When they have completed their drawing, the players get a single physical copy of the drawing to share between them.

Background
In addition to the history of collaborative drawing practices described above, this project was inspired by the aesthetics and interactivity mechanics of early electro-mechanical arcade games. Many of those games create a sense of illusion or visual magic by combining projected or reflected screen-based images with physical objects or printed materials. Also, unlike their screen-based offspring, these electro-mechanical cabinets create a sense of fun by involving the player's physical body in the game.

Audience
While Face Fight could be used by anyone, the interaction it creates will be most interesting for pairs of people with a pre-existing history. The machine forces you to stare directly into the face of your collaborator for an extended period of time, which can create a surprisingly intimate connection. Also, the delicate balance Face Fight creates between collaboration and conflict will be an interesting test for the communication skills of such pre-existing couples.


User Scenario
In order for the projected drawing to be visible, Face Fight should be situated in a relatively darkened environment. The users will need to sit down in chairs across a table-top device so they will need enough room to do that comfortably with margin to move their arms back and forth while playing the game. They will need to have the ability to talk to each other so a relatively quiet environment (where they can at least speak without shouting) would be preferred.

So: two people approach a table-top arcade cabinet-like game, sitting in a dim corner where the ambient noise is no more deafening than a conventional arcade. They take their places on either of the game, adjusting their chairs so they can sit comfortably with their faces and arms in position. They play the game. When they are finished they press a button to receive a printout of their collaborative drawing. They are able to collect that from a nearby printer.

Implementation
Face Fight's moving parts are made from metal draw slides to ensure smooth movement and so that it will not fall apart under vigorous competitive play. See video of the movement fully operational here: http://www.youtube.com/watch?v=mCZx6YKAQoE The movement is detected by a potentiometer (y-axis) and an IR sensor (x-axis) and fed into an arduino connected to a laptop running processing. This laptop's screen is reflected into a transparent piece of plastic positioned in a wooden box between and framing the players faces. The plastic will allow the users to see the emerging drawing between them while still being able through to their partner's faces. See video of a test of this projection here: http://www.youtube.com/watch?v=YWbeE8JTY7U (it's hard to tell in this video, but the drawing is being powered by the sensors on the movement itself; look for the handle in the foreground).