This paper investigates whether the body anticipation synergies in real environments (REs) are preserved during navigation in virtual environments (VEs). Experimental studies related to the control of human locomotion in REs during curved trajectories report a top-down reorientation strategy with the reorientation of the gaze anticipating the reorientation of head, the shoulders and finally the global body motion. This anticipation behavior provides a stable reference frame to the walker to control and reorient his/her body according to the future walking direction. To assess body anticipation during navigation in VEs, we conducted an experiment where participants, wearing a head-mounted display, performed a lemniscate trajectory in a virtual environment (VE) using five different navigation techniques, including walking, virtual steering (head, hand or torso steering) and passive navigation. For the purpose of this experiment, we designed a new control law based on the power-law relation between speed and curvature during human walking. Taken together our results showed a similar ordered top-down sequence of reorientation of the gaze, head and shoulders during curved trajectories between walking in REs and in VEs (for all the evaluated techniques). However, the anticipation mechanism was significantly higher for the walking condition compared to the others. The results presented in this paper pave the way to the better understanding of the underlying mechanisms of human navigation in VEs and to the design of navigation techniques more adapted to humans.

In walkable multi-user HMD-based VR immersed users have to avoid colliding with each other while performing tasks or exploring the virtual environment. This paper presents an experiment in which we compare mutual collision avoidance behaviour of pairs of users walking in the matched real and virtual environments. To generalize our study, we investigate two types of multi-user VR setup: one in which both users share a common tracking space (colocated condition) and one where they move in two separate tracking spaces while sharing a common virtual space (distributed condition). Our results indicated significant differences in locomotor trajectories of participants between the real and virtual conditions. Precisely, we observed an increase in the clearance distance and the median path curvature and a decrease in the walking speed when participants performed the test in VR in the colocated condition. Moreover, we found effects of pre-conditioning between the colocated and distributed scenarios.

The purpose of the experiment presented in this paper is to investigate co-presence and locomotory patterns in a walkable shared virtual environment. In particular, trajectories of users that use a walkable tracking space alone are compared to those of users who use the tracking space in pairs. Co-presence, in a sense of perception of another person being present in the same virtual space is analyzed through subjective responses and behavioral markers. The results indicate that both perception and proxemics in relation to co-located and distributed players differ. The effect on the perception is however mitigated if participants do not collide with the avatars of distributed co-players.

Spatialized audio is the only output that players receive in audio games. In order to provide a realistic view of the environment, it has to be of superior quality in terms of immersion and realism. Complex sound models can be used to generate realistic sound effects, including reflections and reverb. An implementation of a hybrid sound model based on the ODEON approach is introduced and adapted for real-time sound calculations. This model is evaluated and compared to a baseline model usually used in audio games in a user study in a virtual reality environment. The results show that the implemented hybrid model allows players to adjust to the game faster and provides them more support in avoiding virtual obstacles in simple room geometries than the baseline model.