Tzee: Exploiting the lighting properties of multi-touch tabletops for tangible 3d interactions

Manipulating 3D objects on a tabletop is inherently proble-matic. Tabletops lack a third degree of freedom and thus require novel solutions to support even the simplest 3D ma-nipulations. Our solution is TZee – a passive tangible widget that enables natural interactions with 3D objects by exploit-ing the lighting properties of diffuse illumination (DI) multi-touch tabletops. TZee is assembled from stacked layers of acrylic glass to extend the tabletop’s infrared light slightly above the surface without supplemental power. With TZee, users can intuitively scale, translate and rotate objects in all three dimensions, and also perform more sophisticated ges-tures, like “slicing ” a volumetric object, that have not been possible with existing tabletop interaction schemes. TZee is built with affordable and accessible materials, and one table-top surface can easily support multiple TZees. Moreover, since TZee is transparent, there are numerous possibilities to augment interactions with feedback, helpful hints, or other visual enhancements. We discuss several important design considerations and demonstrate the value of TZee with sev-eral applications