Visuo-Haptic Systems: Half-Mirrors Considered Harmful

In recent years, systems that allow users to see and touch virtual objects in the same space (visuo-haptic systems) are being investigated. Most research projects are employing a half-mirror, while few use a video see-through, head-mounted display (HMD). The work presented in this paper points out advantages of the HMD-based approach. First, we present an experiment that analyzes human performance in a target acquisition task. We have compared a half-mirror system with an HMD system. Our main finding is, that a half-mirror significantly reduces performance. Second, we present an HMD-based painting application, which introduces new interaction techniques that could not be implemented with a half-mirror display. We believe that our findings could inspire other researchers, employing a half-mirror, to reconsider their approach