The 3D Multi-Touch Table extends the notion of multi-touch surfaces into the third dimension. Common multi-touch surfaces use total internal reflection to detect the depression of fingers on a side-illuminated surface. To enable true 3D touch, two cameras are mounted at right angles, and the user wears a 3D glove with LED-illuminated fingertips. Tracking software developed for this project allows the cameras to pinpoint the true 3D position of the fingers.
Design interaction enables the user to construct 3D models by extruding (lifting) them from the table surface. Since 3D positions are know, and the geometry of the table is fixed, it is possible to determine when the user touches the glass surface. While sketching on the surface, the user draws 2D curves. Touching a curve with two fingers allows for a curve to be extruded upward into a 3D model.