Hand-as-a-prop: using the hand as a haptic proxy for manipulation in virtual reality

Haptic feedback can be almost as important as visual information in virtual reality environments. On the one hand, in Active Haptic Feedback, specialized devices such as vibrotactile gloves are employed; however, these solutions can be expensive, vendor-specific or cumbersome to setup. On the other hand, Passive Haptic Feedback approaches use inexpensive objects as proxies for the virtual entities; but mapping virtual objects to real props is not scalable nor flexible. We propose the Hand-as-a-Prop technique, which consists in using human hands as object props. We implemented two modalities: Self, where the user’s non-dominant hand act as the virtual object while the dominant hand grabs, translates and releases it; and External, where the hand of another person is used. Hand-as-a-Prop can represent multiple shapes with a single prop and does not require extra hardware. We performed an evaluation comparing both Self and External Hand-as-a-Prop with traditional Object Props in terms of user experience (goodness, ease, realism, fatigue, and preference) and performance (task completion time and translation time). Results showed that Hand-as-a-Prop was rated as neutral tending to positive, and in some cases, the performance was similar to Object Props. Users preferred Self Hand-as-a-Prop over External Hand-as-a-Prop and also obtained better results.