Light Form by Mathieu Rivier is a sculpture that explores different forms of representations and interactions using a solid but uneven display. Each form of interaction consists of an animation that is played on the surface when you touch it. Different sounds are emitted in synchronization with the touch and the animation. The faceted landscape is built on a plinth with integrated projector and infrared sensing to display content that is constrained to the form of the display but offers quite unique interactive experience.
Building and technics
In order for the faceted surface to become a display for multi-touch interaction, it was necessary to design a shape in heat-welded semi-transparent plastic which allows the projection and detection of fingers from inside the structure. The skeleton of the installation is made out of welded steel to insure the rigidity of the structure. The entire structure is surrounded by plywood, which hides the inside. To design the form in PVC, many paper models were created to find the best compromise between the complicated aspect of the form and the finger detection quality. Finally the form was hardened with fiberglass and parget to resist thermoforming. To make the surface interactive, four infrared spots and a revised webcam are installed inside. The program, ccv, detects the overexposed (blob) zones that correspond to pressure points on the form. The information is then sent to another program made in openFrameworks, which calculates the data from the touched points on the form in 3d and then transposed on the flat form. The program generates the graphic on flat surfaces, then sends it to Madmapper which corrects the form and sends it to the projector which is inside the structure. The fact of working with facets, which are flat at first and then distort them for the projection, enables to have an image, which isn’t distorted on each face despite the angle of projection.