Effective manipulation of virtual objects within arm's reach

We present a study that compares finger-based direct interaction to controller-based ray interaction in a CAVE as well as in head-mounted displays. We focus on interaction tasks within reach of the users' arms and hands and explore various feedback methods including visual, pressure-based tactile and vibro-tactile feedback. Furthermore, we enhanced a precise finger tracking device with a direct pinch-detection mechanism to improve the robustness of grasp detection. Our results indicate that finger-based interaction is generally preferred if the functionality and ergonomics of manually manipulated virtual artifacts has to be assessed. However, controller-based interaction is often faster and more robust. In projection-based environments finger-based interaction almost reaches the task completion times and the subjective robustness of controller-based interaction if the grasping heuristics relies on our direct pinch detection. It also improves significantly by adding tactile feedback, while visual feedback proves sufficient in head-mounted displays. Our findings provide a guideline for the design of fine grain finger-based interfaces.