Based on an idea from Roy Ascott, computer animation sequences were created for the elevator of the Ars Electronica Center. In the Ars Electronica Center’s lift, computer animation sequences synchronized with the elevator’s movements are projected from below onto the cabin’s floor.Thus, visitors can move about within a video sequence, and the linear video becomes a transparent and interactive medium.
In order to provide passengers with the illusion of motion, the elevator’s movements and the animation must be synchronized as precisely as possible, especially during acceleration and deceleration phases. However, since the behavior of the lift cabin when it’s in motion cannot be predicted down to the tenth of a second, it’s impossible to work with prerecorded animation sequences. For this reason, the animation was rendered with a frame rate that is four time higher than normal, whereby the playback speed can be reduced to as low as a quarter of the regular rate.
From real-time elevator movement data, a script computes the necessary speed of the animation and transmits the appropriate frames via the perception board to the projector. At normal elevator speed, only every fourth frame is displayed. When the cabin stops at a floor or subsequently moves on, every third, every second, or every single frame is displayed during the respective deceleration and acceleration phases. In this way, the animation is always played back at a constant rate of 25 frames/second, which delivers a smooth-running video sequence to the human eye.
Volker Christian, Hermann Wakolbinger
Keyresearcher / Interactive Spaces: