Touch - interactive urban installation

Commissioner: Dexia
Artists: LAb[au]
Architects: Philippe Samyn & Partners, M & J.M. Jaspers - J. Eyers & Partners
Lightning engineer: Barbara Hediger

Touch is a project by the Belgian digital design and art lab, LAb[au], Laboratory for Architecture and Urbanism.

The 'Touch' project aims to transform the general perception of a media façade, in this case the Dexia Tower, from a marketing and corporate image device towards an urban light art work. The challenge lies in the design of participation and identification through interaction which involves every user with the setting up of an urban landmark. From this point of view the illumination concept is the design of communication. The project considers Brussels Dexia tower not as a media façade, a screen-like device, displaying pre-rendered video loops or images, but works on the architectural characteristics of the building.

On Brussels' Rogier Place, at the bottom of the tower, a multi touch screen is mounted where people, both individually and collectively, can interact in real time. The interaction is constituted by both static and dynamic inputs and takes parameters of size (finger, hand), direction (horizontal, vertical, diagonal) and duration (introducing growth) into account. The user's inputs establish a play of graphical elements inspired by abstract art such as Mondriaan's 'elementarism' and Kandinsky's 'point and line to plane'. These geometric figures are associated to the building as follows: points = pixels = windows, lines and diagonals = levels and edges, and surfaces = the facades. These shapes are displayed in real-time on top of a monochromatic light which the user defined in a first step whereas

the shapes are displayed in black and white according to the positive or negative (up/down, left/right...) direction of his input. The project gives the inhabitants of Brussels the possibility of interacting with the building - establishing a new relation between architecture and the citizen. Here a simple finger tip of a person changes the appearance of an entire building, a 145m high tower.

Once a composition is created, it can be sent as an electronic postcard showing a snapshot from the tower, taken from a distant location and streamed back to the pavilion's interface. It is also uploaded on a specific project website where people can retrieve their composition, in a printable format, with Christmas and New Year's wishes from Brussels. The user's interactions could be seen from all over the city, an action taking part in the general image of the city, an image s/he could retrieve and share. The project thus relies on a communication process linking up the individual with the building and the public space of the city. This communication design, (due to the use of advanced technologies), allows public space to be experienced in a hitherto unknown manner and involves each person, through interaction, in the 'meaning' a light architecture can have within the urban realm. In this manner the inauguration project for the illumination system established from the very first moment of its appearance the ambitions of its conception.)

The construct of interfaces

The design of the interface is based on the idea of unfolding the tower to the bi-dimensional surface of the multi-touch screen allowing a coherent mapping of the actual building. The aim of this mapping is to establish a direct relation between the pixel resolution of the screen-space and the actual building giving the user an intuitive means of interaction. Following this objective the gesture recognition has been reduced to simple inputs and direct feed-back in order to focus the users' intention and vision towards the tower rather than to the interface. For example the first user input is to touch the screen at any point; a point from which the tower gets illuminated; a point which becomes a vertical line and

than unfolds like a curtain over the entire building. Its colour results from the mapping of the screen surface to the spectrum of visible light. Here a simple user input results in a dramatic chromatic change of the tower, an opening sequence which underlines the intended relation between user inputs and the tower and which directly translates the notion of 'touch'.

But the interface wasn't limited to the design of a screen interface: it was extended to the design of an entire pavilion to cope with the scale of the urban context. The pavilion embodies three parts: the first fold allows people to interact on a multi-touch-screen, the second fold directly displays the user interaction - finger drawing - on a projection screen and the third fold frames the user's vision towards the tower. In this manner the station not only establishes a direct relation to the visual and luminous construct of the tower but also displays to the passers-by the ongoing process of user interaction. The pavilion thus became an interface by itself between the city and the tower. The project thus uses interactivity not as being a control system but rather as a catalyst to establish a link in between the citizens, the citizen and the building, the building and the city.