The “CGN Caleidoscope” is an electronic game that allows visitors to create geometric shapes by simply moving their hands. The visitor controls a ribbon that is doubled several times on the screen by a feedback process, like in a kaleidoscope.

When approaching one sensor, the ribbon moves to the left, when approaching the other sensor, it moves to the right. When the ribbon hits the edge, it is reflected and the direction of rotation changes.

The program is based on an iterative process with a hidden image memory at its core: First, a screenshot is taken of the screen, then a square area of the screen is copied into this hidden image memory. The ribbon is then drawn on the screen.  Thirds, the hidden image memory is then copied back to the screen, where it is rotated and resized during this operation.

We digitalized historical exhibition flyers from the Bundeskunsthalle to create an digital picture archive for the visitor to look through. The observed images could be “swiped” to the right or left by simple hand gestures; long before “swiping” was a thing.