ObjecTop: Occlusion Awareness of Physical Objects on Interactive Tabletops

In this paper, we address the challenges of occlusion created by physical objects on interactive tabletops. We contribute an integrated set of interaction techniques designed to cope with the physical occlusion problem as well as facilitate organizing objects in hybrid settings. These techniques are implemented in ObjecTop, a system to support tabletop display applications involving both physical and virtual objects. We compile design requirements for occlusion-aware tabletop systems and conduct the first in-depth user study comparing ObjecTop with conventional tabletop interfaces in search and layout tasks. The empirical results show that occlusion-aware techniques outperform the conventional tabletop interface. Furthermore, our findings indicate that physical properties of occluders dramatically influence which strategy users employ to cope with occlusion. We conclude with a set of design implications derived from the study. Author Keywords Interactive tabletop displays, occlusion awareness, hybri