Steering techniques are common for traveling in Virtual Reality (VR) applications. However, these techniques can generate Unintended Positional Drift (UPD), a phenomenon characterized by the user’s unconscious or unintentional physical movements of the users in the workspace. Although some research work has already investigated the influence of heading (i.e., how the virtual trajectory direction is updated) and cognitive load on travel performance using steering techniques, they did not investigate whether these factors could increase UPD. In this paper, we thus replicated and extended an existing user study to assess the influence of heading and cognitive task (CT) on UPD while navigating with steering techniques in VR. Participants had to perform a multidirectional travel task (based on the ISO 9241-9) while doing a CT (two-back task). We considered conditions with and without performing the CT, where we varied the steering heading (head, hand, torso). We compared our results with those of a previous study and found that the heading did not influence users’ travel and cognitive performance. However, we noticed the influence of workload on the user’s UPD. This work contributes to understanding UPD, which tends to be an overlooked topic, and the cognitive implications of navigation in VR. We discuss the design implications of these results for improving navigation in VR.

We present a novel shape-shifting haptic device, Shiftly, which renders plausible haptic feedback when touching virtual objects in Virtual Reality (VR). By changing its shape, different geometries of virtual objects can be approximated to provide haptic feedback for the user's hand. The device employs only three actuators and three curved origamis that can be programmatically folded and unfolded to create a variety of touch surfaces ranging from flat to curved. In this paper, we present the design of Shiftly, including its kinematic model and integration into VR setups for haptics. We also assessed Shiftly using two user studies. The first study evaluated how well Shiftly can approximate different shapes without visual representation. The second study investigated the realism of the haptic feedback with Shiftly for a user when touching a rendered virtual object. The results showed that our device can provide realistic haptic feedback for flat surfaces, convex shapes of different curvatures, and edge-shaped geometries. Shiftly can less realistically render concave surfaces and objects with small details.

Unintended Positional Drift (UPD) is a phenomenon that occurs during navigation in Virtual Reality (VR). It is characterized by the user’s unconscious or unintentional physical movements in the workspace while using a locomotion technique (LT) that does not require physical displacement (e.g., steering, teleportation). Recent work showed that some factors, such as the LT used and the type of trajectory, can influence UPD. However, little is known about the influence of rotation gains (commonly used in redirection-based LTs) on UPD during navigation in VR. In this paper, we conducted two user studies to assess the influence of rotation gains on UPD. In the first study, participants had to perform consecutive turns in a corridor virtual environment. In the second study, participants had to explore a large office floor and collect spheres freely. We compared the conditions between rotation gains and without gains, and we also varied the turning angle to perform the turns while considering factors such as sensitivity to cybersickness and the learning effect. We found that rotation gains and lower turning angles decreased UPD during the first study, but the presence of rotation gains increased UPD in the second study. This work contributes to the understanding of UPD, which tends to be an overlooked topic and discusses the design implications of these results for improving navigation in VR.

Virtual steering techniques enable users to navigate in larger Virtual Environments (VEs) than the physical workspace available. Even though these techniques do not require physical movement of the users (e.g. using a joystick and the head orientation to steer towards a virtual direction), recent work observed that users might unintentionally move in the physical workspace while navigating, resulting in Unintended Positional Drift (UPD). This phenomenon can be a safety issue since users may unintentionally reach the physical boundaries of the workspace while using a steering technique. In this context, as a necessary first step to improve the design of navigation techniques minimizing the UPD, this paper aims at analyzing and modeling the UPD during a virtual navigation task. In particular, we characterize and analyze the UPD for a dataset containing the positions and orientations of eighteen users performing a virtual slalom task using virtual steering techniques. Participants wore a head-mounted display and had to follow three different sinusoidal-like trajectories (with low, medium and high curvature) using a torso-steering navigation technique. We analyzed the performed motions and proposed two UPD models: the first based on a linear regression analysis and the second based on a Gaussian Mixture Model (GMM) analysis. Then, we assessed both models through a simulation-based evaluation where we reproduced the same navigation task using virtual agents. Our results indicate the feasibility of using simulation-based evaluations to study UPD. The paper concludes with a discussion of potential applications of the results in order to gain a better understanding of UPD during steering and therefore improve the design of navigation techniques by compensating for UPD.

In this paper, we present the design of ten different 3D user interactions using passive haptics and embedded in an escape game scenario in which users have to escape from a pyramid in a limited time. Our solution is innovative by its modularity, allowing interactions with virtual objects using tangible props manipulated either directly using the hands and feet or indirectly through a single prop held in the hand, in order to perform several interactions with the virtual environment (VE). We also propose a navigation technique based on the “impossible spaces” design, allowing users to naturally walk through several overlapping rooms of the VE. All together, our different interaction techniques allow the users to solve several enigmas built into a challenging scenario inside a pyramid.

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.