Interactive Architecture
Short Descriptions of his Works


In interactive architecture, the viewer becomes the pivot of the installation; s/he is the constitutive and active part of the architecture, which is set in motion by the viewer when detected by sensors. This triggers the changing form of the installations. The perspective is divided from the outset: the viewer not only sees the work, but is in turn perceived by the installation and the two form an interactive system.

The shattering of the habitual perspective accentuates the degree to which perception of all spatial phenomena is relative to the viewer, and activating the whole issue goes hand in hand with a further disruption: interactive architecture presents itself in a tangible, sensuous form that unsettles our very day-to- day perception of things.

In the interactive installations featured below, the tactile becomes visible, the visible becomes audible and the acoustic, visible. Interactive architecture conveys impressions in another sense dimension: what is cast into question and becomes an object of playful development is the medium in which things appear to us.

In the spatial installations, reflection on the media is given a special profile. These barren, pure spaces, which - if one ignores the high-tech equipment - have only themselves as furnishings. They exude a feeling of stability when the viewer enters them. Stability is linked to a medium, and a medium with the appearance of architecture is, for example, made up of its irreversibility. Stone upon stone, a spatial chronology which predestines them to become stone witnesses to millennia. This medium is torn asunder by virtual spaces that rest on electronic media, with their fast forward and instant replay, their recursive, reversible nature.

Cinematoscope: An Installation

A co-production with TAT (Theater am Turm) in the subway between the Hauptwache and Eschersheimer Tor subway stations in Frankfurt in 1991. The project proved to be impossible to realize, as the city transport authority believed that safety could not be guaranteed.

Speed serves us all solely to further the aim of getting from Point A to Point B--if we disregard those people who jog through the woods or along the streets in order to keep fit or achieve recognition in their sport, or those who get a buzz out of high speed, or seek to realize some dream of flying in free fall. Owing to our daily habits, we hardly take note any longer of the phenomena whereby we move relatively effortlessly with astonishing speed. If speed becomes an event that we notice in everyday life, it is usually as a result of an accident or catastrophe.

Cinematoscopes were developed at the end of the 19th century and were all the rage at fairs. In a simpler version, they were sold as toys for the children of well-to-do families.

The linear cinamoscope is based on the same optic principle. It involves not a drum but a line of pictures of random length being created by using a fixed installation with two layers of walls. The first layer, which the viewer looks at, consists of a black screen with small slit-like openings at regular intervals. The pictures are positioned three meters behind the screen on the tunnel wall.

The individual pictures, mounted on fiberboard, are hung on a simple latticework construction attached to the tunnel wall. The screen wall-- matt black and complete with slits-- is positioned between the supporting columns bearing the roof of the tunnel. Halogen spotlights are located along the axis of the supporting columns in the space between the lower edge of the reinforced concrete ceiling and the upper edge of the screen.

The viewer travels past the linear cinematoscope at a speed of approximately 50 kph and thus enjoys a film at 12 frames per second or the complete length of the installation. A photoelectric barrier at the entrance and exit to the tunnel switch the halogen spots on and off.

Technical Consultant

Klaus Bollinger, Frankfurt

Space Balance

A real building with a virtual interior is at the same time in different states of equilibrium. The experiment, entitled "Space Balance", was presented in the Danube Park as part of the ARS Electronica 92 Festival in Linz, Austria.

The exterior is formed by a 16 x 2 meter wide box-like body. The viewer enters the interior through a light trap in the middle of the building. The viewer sees the interior in virtual and life-size form via back projection onto the projection surfaces mounted directly behind and in front of him or her. To this end, two CAD large-screen data projectors are used. Two networked computers (Silicon Graphics Indigos ELAN) calculate and draw a real-time image of the continually changing interior perspective. In the narrow space between the projection surfaces, the geometry of the walls, ceiling and floor correspond to their virtual depiction on the two screen surfaces.

The viewer stands in virtual space.

The floor in the central area of the part of the installation to which the viewers have access is itself flexible: the floor tilts like a seesaw depending on where the viewer stands, yet in such a way that the room always remains at right angles to the floor. Loudspeakers are positioned at the front and back of the structure, i.e., respectively 8 meters from the middle. These play the computer-controlled digitalized sound of the contact the "collision" of the virtual balls in the room -- thus providing an acoustic simulation of the point of collision. The human sense of balance is irritated by all this. You feel the same sensation of being at sea, below deck during an ocean cruise. However, unlike on a cruise, the viewer in the installation controls the movement of the waves. If the illusion thus created is complete, the experience after you have left the installation and have "terra firma" under your feet is that you still have to fight to regain your balance.

Programming by

Dieter Beck, Langen

This project was made possible by

the generous assistance of MBM Metallbau, Mockmuhl GmbH and Stadelschule,

Institut fur Neue Medien, Frankfurt.

Kinetic Light for the Zeilgalery (1992)

"On Justifying the Hypothetical Nature of Art and its Non-Identity with the Object World"

Construction of real and virtual architecture for the installation by Peter Weibel, the artist, at the Tanja Grunert Gallery in Cologne, 1992.

This is a permanent installation on the facade of the Zeilgalerie. In this case, interactive architecture visualises something that can otherwise only be felt by the skin:  temperature, wind and humidity. It also transforms the utterances of passers by into tonal sculptures.

This light sculpture significantly changes the appearance of the folded aluminium wall between day and night. By day, the perforated sheet metal in front of a blue building facade remains grey and reserved, oscillating only through the play of daylight. When dusk falls, it transforms itself into blue-yellow floating figures, which depending on weather conditions, faces up or down and varies in yellow intensity, controlled by three groups of light totalling 120 spots shining from inside and outside the layer of sheets in front of the building wall.

The image of the facade is controlled by a Silicon Graphics Indigo computer, fed with data from a weather station on top of the building. The temperature determines the level of yellowness, the yellow patches orient themselves according to wind direction or rain level.

A 3-by-16 metre LED display across the top of the facade visualises the degree of sound made by passers by, or during the day it act a a message board for local news.

Surfaces of Variable Visibility

These were first tested as an installation in the Saint Roche assembly in Brussels in 1992.

The surfaces of variable visiblity are formed by vertically positioned rectangular surfaces placed one behind the other. They consist of a large-size LCD film between two thin panes of laminated glass. By electrical inputs of between 0 and 118 volts, the glass surface, which is opaque when the current changes in line with the changes in the translucency of the glass.

A computer system controls the on/off switching and voltage is passed through the LCD films. Its sensors detect outside noise and the respective position of the viewer and it sets in motion the surface on which the image is shown by changing the amout of light flooding through the film. If the viewer stands at the front end of the installation, then the surface on which the image appears comes closer and moves further away in a rhythmical, pulsating movement.

Programming: Daniel Schmitt, Dietzenbach

Levels of variable Visibility - Electronic Mirror 1

The mirror will be displayed at the exhibition on The Inner World of Equipment World to be held at the Institute for the New Media attached to the Städle Art Academy, Frankfurt, in 1993, and is a piece from a series on surfaces of variable visibility.

A mirror is mounted in a frame behind a pane of private lite - a large size LCD film between two thin panes of laminated glass. By introducing the LCD-film the pane can be rendered transparent to varying degrees. The film is manipulated via a computer controlled dimmer switch. An ultra sonic sensor (Siemens Sonar) measures the viewer's distance from the mirror image surface and feeds this information to a PC (using 288 chips) which then modifies the degree of transparency of the pane and thus the sharpness of focus of the image via the dimmer.

What occurs is a self portrait of the viewer with the focus altered. Each point along the middle axis of the room corresponds to a specific degree of transparency of the mirror pane. By walking closer or further away, the viewer can change how sharply the mirror portrays the contours of his or her person.

programming: Daniel Schmitt, Dietzenbach

The project was made possible with the kind of support of Siemens AG, Frankfurt.

Surfaces of Variable Visibility - framed by images

The installation was a part of the Chapter three exhibition in the cloisters of the Carmelite Monastery in Frankfurt on Main.

This glass installation in the cloisters of the Carmelite monastery in Frankfurt can only be viewed if the viewer moves around. The cloisters, which symbolise the switch from blindness to light, which in turn can only be viewed by movement through it, also reflects on the change from historical to interactive architecture.

The surfaces are marked out between two vertically-positioned rectangular surfaces like a line of pods erected one behind the other. The surfaces are not material but imaginary and first become visual when the viewer moves through them. The surfaces fix spatial boundaries but remain electronically flexible.

A computer system calculates the space between the front and back walls of the installation and creates referential surfaces. The ultra-sonic sensor conveys this information to the computer. A window opening,m covered over with a pane of Priva- Lite is inserted in the front wall of the installation, consisting of a video monitor and a videodisc player.

Each surface measured by the computer in the space of the installation corresponds to both a predetermined sequence of images on the video disc and a specific degree of transparency of the LCD film in the pane. The viewer directs the sequence of images screened on the monitor and the translucency of the glass surface by moving up and down the interactive space. Floor markings are provided as an orientation guide and bear the mainframe numbers of the video disc.

Programming: Daniel Schmitt, Dietzenbach

Photography: Stefan Morgenstern, Frankfurt

The project was made possible by the kind support of Siemens AG ASI/Appliences Factory,

Amberg and Städelschule, Institut für Neue medien, Frankfurt.

Unseen Vision-- An Aural space

The installation is located in a 10- by-12 metre room - the same size as the average stage in a theatre. An accessible, adjustable and hydraulically muffled glass platform stands in the centre of the room. Sensors transmit the respective angle of the platform to an Iris-Indigo workstation in the next room which is, in turn, networked into a second Indigo system in the Theatre's foyer.

Sound in the room is generated by a five-channel audio system, with a loudspeaker located in each of the four corners of the room. An additional speaker is, in addition, mounted above the platform. Each of the five channels is controlled individually by the Indigo computer system with the help of a MIDI mixer.

A screen for back projection measuring 3-by-4 meters is positioned in the hall between the two rooms. A video projector located in the ceiling area of the adjacent room projects realtime computer graphics onto the back of the screen.

Both computer systems are linked via Ethernet and the same program runs on both. The database contains a wire-frame model of the room in which a swarm of dots move, pursuing one another (the creature). The swarm moves in the room in relation to the angle of the platform which moves in reaction to the weight of the viewer. The swarm is linked to two different sounds which are moved by the audience through the space - as the perceptible expressions of the creature.

Two possible modes of viewing are generated simultaneously by the two interlinked computer systems: the viewer finds him/herself in the computer model of the room and occasionally sees a shadow on the screen whenever the creature moves between viewer and screen; or the monitor mounted in the foyer shows viewers there a virtual bird's eye image of the whole installation room via a camera positioned outside. From this vantage point, the swarm- like being in the installation room can be watched the whole time, as it is moved around the room interactively by the viewer.

A co-production with TAT (Theater am Turm) in Frankfurt, February 1993.

Composition and audio-technology: Peter Kuhlman, Frankfurt

Programming: Gideon May, Amsterdam and Karlsruhe

Natural Sound Insects: David Dunn, USA

The project was made possible by the friendly assistance provided by MBM Metallbau Möckmühl GmbH and Städelschule, Institut für Neue medien, Frankfurt.


The installation in the former subway tunnel at Unter den Linden presents historical pictures of the destruction of Berlin from the dramatic viewpoint of a contemporary observer. On display are sequences of pictures showing Berlin prior to and after the Second World War which mirror the time- cage of the viewers walking round them. This time-cage, a colourful 5 metre-wide and one metre-high wooden structure mounted in the middle of the tunnel installation, constitutes the viewer's sphere of action. By moving back and forth sideways across the years marked on the floor of the frame viewers trigger pictures of Berlin from the respectively activated years that are then projected onto the two screens in front and behind the cage. The pictures of the destruction of Berlin thus match the viewer's sidesteps.

This `interactive view of history' is generated by means of an ultrasonic sensor placed behind one of the front sides of the `cage'. It is linked to a computer system that continuously monitors where - on which marked year - the viewer happens to be. The time in the Chronolysis is the time of destruction: there are no flows here, but rather leaps in time. In the form of insect noises transmitted down the longitudinal axis of the tunnel by loudspeakers, visitors to the exhibition also control the acoustics of destruction: they move the swarming noise down along the tunnel.

Sounds: David Dunn

Programming: Daniel Schmitt, Sven Thöne

film sequences: Oskar Sala

The project was made possible by the kind support of the Preussischer Kulturbesitz's Picture Archive,Art + Com Berlin and Siemens AG, ASI/Gerätewerk Amberg.

Light Blaster

The Light Blaster installation first went on show in Frankfurt's Naxos Hall during Design Horizonte 93.

The side of the installation which faces the viewer is made up of a 4- by-5 metre wall of light. A water- cooled 4 watt argon laser scans this plane of light into the space by projecting its blue-green laser by glass fibre light conductors onto a highly reflective surface mirror positioned at a 45 degree angle and rotating at 2,000 rpm. The scanner mechanism rests on a three metre long, computer-controlled forward- feed toothed belt.

An electronic sensor communicates the viewer's pulse rate to the computer. The pulse signal moves the light plane backwards and forwards in a motion that corresponds to the beating of the viewer's heart. A loudspeaker system behind the wall of light transmits the audio impulses and acoustically supplements the pulsating motion of the wall of light in the room.

Programming: Daniel Schmitt, Sven Thöne

Laser technology: Harmut Florin

The project was made possible with the kind support of MBM Metallbau Möckmühl, Bison Lasertechnik, ISEL Automation and Nellcor.

Text: Susanne Craemer


updated 1993