Optimizing Natural Walking Usage in VR using Redirected Teleportation

Virtual Reality (VR) has come a long way since its inception and with the recent advancements in technology, high end VR headsets are now commercially available. Although these headsets offer full motion tracking capabilities, locomotion in VR is yet to be fully solved due to space constraints, potential VR sickness and problems with retaining immersion. Teleportation is the most popular locomotion technique in VR as it allows users to safely navigate beyond the confines of the available positional tracking space without inducing VR sickness. It has been argued that the use of teleportation doesn’t facilitate the use of natural walking input which is considered to have a higher presence because teleportation is faster, requires little physical effort and uses limited available tracking space. When a user walks to the edge of the tracking space, he/she must switch to teleportation. When navigating in the same direction, available walking space does not increase, which forces users to remain stationary and continue using teleportation. We present redirected teleportation, a novel locomotion method that increases tracking space usage and natural walking input by subtle reorientation and repositioning of the user. We first analyzed the positional tendencies of the users as they played popular games implementing teleportation and found the utilization of the tracking space to be limited. We then compared redirected teleportation with regular teleportation using a navigation task in three different environments. Analysis of our data show that although redirected walking takes more time, users used significantly fewer teleports and more natural walking input while using more of the available tracking space. The increase in time is largely due to users walking more, which takes more time than using teleportation. Our results provide evidence that redirected teleportation may be a viable approach to increase the usage of natural walking input while decreasing the dependency on teleportation

Effects of head-slaved navigation and the use of teleports on spatial orientation in virtual environments

The type of navigation interface in a virtual environment (VE) - head slaved or indirect - determines whether or not proprioceptive feedback stimuli are present during movement. In addition, teleports can be used, which do not provide continuous movement but, rather, discontinuously displace the viewpoint over large distances. A two-part experiment was performed. The first part investigated whether head-slaved navigation provides an advantage for spatial learning in a VE. The second part investigated the role of anticipation when using teleports. The results showed that head-slaved navigation has an advantage over indirect navigation for the acquisition of spatial knowledge in a VE. Anticipating the destination of the teleport prevented disorientation after the displacement to a great extent but not completely. The time that was needed for anticipation increased if the teleport involved a rotation of the viewing direction. This research shows the potential added value of using a head-slaved navigation interface - for example, when using VE for training purposes - and provides practical guidelines for the use of teleports in VE applications

Human Visual Navigation: Effects of Visual Context, Navigation Mode, and Gender

Abstract This thesis extends research on human visual path integration using optic flow cues. In three experiments, a large-scale path-completion task was contextualised within highly-textured authentic virtual environments. Real-world navigational experience was further simulated, through the inclusion of a large roundabout on the route. Three semi-surrounding screens provided a wide field of view. Participants were able to perform the task, but directional estimates showed characteristic errors, which can be explained with a model of distance misperception on the outbound roads of the route. Display and route layout parameters had very strong effects on performance. Gender and navigation mode were also influential. Participants consistently underestimated the final turn angle when simulated self-motion was viewed passively, on large projection screens in a driving simulator. Error increased with increasing size of the internal angle, on route layouts based on equilateral or isosceles triangles. A compressed range of responses was found. Higher overall accuracy was observed when a display with smaller desktop computer monitors was used; especially when simulated self-motion was actively controlled with a steering wheel and foot pedals, rather than viewed passively. Patterns and levels of error depended on route layout, which included triangles with non-equivalent lengths of the two outbound roads. A powerful effect on performance was exerted by the length of the "approach segment" on the route: that is, the distance travelled on the first outbound road, combined with the distance travelled between the two outbound roads on the roundabout curve. The final turn angle was generally overestimated on routes with a long approach segment (those with a long first road and a 60° or 90° internal angle), and underestimated on routes with a short approach segment (those with a short first road or the 120° internal angle). Accuracy was higher for active participants on routes with longer approach segments and on 90° angle trials, and for passive participants on routes with shorter approach segments and on 120° angle trials. Active participants treated all internal angles as 90° angles. Participants performed with lower overall accuracy when optic flow information was disrupted, through the intermittent presentation of self-motion on the small-screen display, in a sequence of static snapshots of the route. Performance was particularly impaired on routes with a long approach segment, but quite accurate on those with a short approach segment. Consistent overestimation of the final angle was observed, and error decreased with increasing size of the internal angle. Participants treated all internal angles as 120° angles. The level of available visual information did not greatly affect estimates, in general. The degree of curvature on the roundabout mainly influenced estimates by female participants in the Passive condition. Compared with males, females performed less accurately in the driving simulator, and with reduced optic flow cues; but more accurately with the small-screen display on layouts with a short approach segment, and when they had active control of the self-motion. The virtual environments evoked a sense of presence, but this had no effect on task performance, in general. The environments could be used for training navigational skills where high precision is not required