Efficient Bimanual Symmetric 3D Manipulation for Bare-Handed Interaction

Recently, stable markerless 6 DOF video based handtracking devices became available. These devices simultaneously track the positions and orientations of both user hands in different postures with at least 25 frames per second. Such hand-tracking allows for using the human hands as natural input devices. However, the absence of physical buttons for performing click actions and state changes poses severe challenges in designing an efficient and easy to use 3D interface on top of such a device. In particular, for coupling and decoupling a virtual object’s movements to the user’s hand (i.e. grabbing and releasing) a solution has to be found. In this paper, we introduce a novel technique for efficient two-handed grabbing and releasing objects and intuitively manipulating them in the virtual space. This technique is integrated in a novel 3D interface for virtual manipulations. A user experiment shows the superior applicability of this new technique. Last but not least, we describe how this technique can be exploited in practice to improve interaction by integrating it with RTT DeltaGen, a professional CAD/CAS visualization and editing tool.

Influence of Comfort on 3D Selection Task Performance in Immersive Desktop Setups

Immersive virtual environments (IVEs) have the potential to afford natural interaction in the three-dimensional (3D) space around a user. However, interaction performance in 3D mid-air is often reduced and depends on a variety of ergonomics factors, the user's endurance, muscular strength, as well as fitness. In particular, in contrast to traditional desktop-based setups, users often cannot rest their arms in a comfortable pose during the interaction. In this article we analyze the impact of comfort on 3D selection tasks in an immersive desktop setup. First, in a pre-study we identified how comfortable or uncomfortable specific interaction positions and poses are for users who are standing upright. Then, we investigated differences in 3D selection task performance when users interact with their hands in a comfortable or uncomfortable body pose, while sitting on a chair in front of a table while the VE was displayed on a headmounted display (HMD). We conducted a Fitts' Law experiment to evaluate selection performance in different poses. The results suggest that users achieve a significantly higher performance in a comfortable pose when they rest their elbow on the table.