Lightstrivefor: meso image spaces
During the Olympics of 2004 in Athens a series of installations was set up around the city as part of the cultural program accompanying the games. One of them was Lightstrive which we realized in cooperation with Michael Höpfel. Lighstrive is an interactive facade projection whereby the facade is lit by an invisible lightsource that seems to be moving in front of the building. In the lower part of the building that lightsource manifests itself in the form of a ball that passers by can kick with their shadows thus influencing the way shadows are being cast on the facade.
The bank building with its different types of balkonies was a very good target as the architecture would cast many shadows onto itself.
As the virtual light ball flying in front of the building was also interacting with the architecture, it was sometimes caught in a balkony causing a kind of magic light situation.
On the lower part of the building a screen was hung to have a flat surface where players see their shadows interacting with the ball. A camera was pointed at that screen from the opposite side of the street to analyze the shadows that would influence the physics of the ball.
A 3d geometry representation of the facade was created and projected to fit exactly onto the architecture. The images below show the 3d geometry rendered in wireframe mode during setup.
The setup needed a lot of manual calibration to get both real and virtual shadows connected to people, architecture and virtual light source. Here are some impressions of this process:
Documentation on hoepfel.net