“Interactive chalk cars” is an installation based on a traditional children's game, that was originally played on the streets. It uses new digital technologies to review a non-technological game. By using computer vision algorithms and projection mapping, it brings together the real and the virtual. In doing this, we try to combine two playing modes that are usually confronted: the individual video game and the outdoor social game.

The installation has two parts:

Drawing: where users draw the circuit with chalk. The circuit can be erased or re-drawn at any point during the game. The system dynamically recognizes the chalk drawing.

Playing: two virtuals cars are controlled by users using a hand made controller. Virtual cars crash against each other and against the chalk lines/boundaries of the circuit. The game has no pre-established rules (number of laps, time limits, etc...). The players make them up each time, just as we did when we were children.

Virtual cars crash against each other and against the chalk lines/boundaries of the circuit. The game has no pre-established rules (number of laps, time limits, etc...). The players make them up each time, just as we did when we were children.

The circuit can be erased or re-drawn at any point during the game. The system dynamically recognises the chalk drawing.

The installation has been programmed using Openframeworks with Opencv for the circuit recognition and Madmapper for the mapping.