Duopography: using back-of-device multi-touch input to manipulate spatial data on mobile tangible interactive topography

In this short paper we present the design of Duopography1, a dual-surface mobile tangible interface for spatial representation and manipulation of topography. The 3D physical topographic front of Duopography acts as a tangible interface, enabling sketching directly on the 3D terrain, as well as visual augmentation of the topography. At the same time, Duopography's flat back-of-device supports gestures that are hard to perform on the irregular front, allowing common interaction techniques such as panning and pinching. We contribute a prototype and the results of a preliminary evaluation of a dual-surface topography interface combining 3D printed front and a flat back-of-device.