The tangible 3D tabletop combines tangible tabletop interaction with 3D projection in such a way that the tangible objects can be augmented with visual data corresponding to their physical shape, position and orientation on the tabletop. In practice, this means that not only the tabletop but also the tangibles themselves can serve as displays.

We present the basic ideas for this interface, particularly concerning the interplay between 2D and 3D on the tabletop and the tangibles, and present examples of how it might be used in the domain of maps and geolocalised data.

This concept also leads to discuss design considerations concerning the combination and connection of content and functions of tangibles and tabletop surface, the use of tangibles as dynamic displays and input devices, and the visual effects made possible by the combination of 2D and 3D on tabletop surface and tangibles.