Lightpools or El Ball del Fanalet (1998, by Perry Hoberman and Galeria Virtual) takes place in a circular arena approximately six meters in diameter, onto which a real-time computer generated image is projected from above. Each user is given one of four fanalets as they enter the arena, each containing a colored light with a battery pack and a position sensor. The sensor reports its position to a host computer, allowing each fanalet's position to be tracked in three-dimensional space. The two horizontal dimensions are used to position a colored circle of light projected onto the floor directly below each fanalet. The third dimension (height) is used to determine the size and brightness of the lightpool, so that its behavior mimics the effect of a light source emanating from the fanalet: as the fanalet is lowered, the pool becomes smaller and more intense; as it is raised, the pool becomes larger and dimmer. This gives users the impression that the lightpool is projected directly from their fanalet, and gives them an immediate, intuitive sense of how to interact with the work.
Each lightpool is a kind of window onto a virtual ground plane, which otherwise remains shrouded in darkness. Virtual objects become the user's "partner" and can be trained to dance. From these interactions emerges a complex, ever-changing dance of participants and virtual objects. The atmosphere is one of a casual but concentrated chaos, as users observe and interact with their objects and each other. The installation exists in the area of what might be called casual or open-ended interactivity, an attempt to create the conditions under which an interactive, immersive image can be experienced as a casual, open, social space.