Check our projects.

The Effect of Field-of-View Restriction on Gender Bias in VR Sickness

Recent studies show that women are more susceptible to visually-induced VR sickness, which might explain the low adoption rate of VR technology among women. Reducing field-of-view (FOV) during locomotion is already a widely used strategy to reduce VR sickness as it blocks peripheral optical flow perception and mitigates visual/vestibular conflict. Prior studies show that men are more adept at 3D spatialnavigation than women, though this gender bias can be minimized by providing women with a larger FOV. Our study provides insight into the relationship between gender and FOV restriction with respect to VR sickness and spatial navigation performance which seem to conflict. We find the use of an FOV restrictor to be effective in mitigating VR sickness in both genders while it does not impede their spatial navigation performance.

On publication (2019)

Teleportation without Spatial Disorientation using Optical Flow Cues

Teleportation is a popular locomotion technique that lets users navigate beyond the confines of limited available positional tracking space. Because it discontinuously translates the viewpoint, it is considered a safe locomotion method because it doesn’t generate any optical flow, and thus reduces the risk of vection induced VR sickness. Though the lack of optical flow minimizes VR sickness, it also limits path integration, e.g., estimating the total distance travelled, and which can lead to spatial disorientation. This paper evaluates a teleportation technique called Dash that quickly but continuously displaces the user’s viewpoint and which retains some optical flow cues. A user study with 16 participants compares Dash to regular teleportation and found that it significantly improves path integration while there was no difference in VR sickness.

Published in Proceedings of Graphics Interface

Walking-in-Place using Inertial Sensing for Hands Free Navigation in Mobile VR

Low-cost smartphone adapters can bring virtual reality to the masses, but input is typically limited to using head tracking, which makes it difficult to perform complex tasks like navigation. Walking-in-place (WIP) offers a natural and immersive form of virtual locomotion that can reduce simulation sickness. WIP, however, is difficult to implement in mobile contexts as it typically relies on bulky controllers or an external camera. We present VR-step; a WIP implementation that uses real-time pedometry to implement virtual locomotion. VR-step~requires no additional instrumentation outside of a smartphone’s inertial sensors. A user study with 18 users compares VR-step with a commonly used auto-walk navigation method and finds no significant difference in performance or reliability, though VR-step~ was found to be more immersive and intuitive.

Published in 2016 CHI Conference on Human Factors in Computing Systems

PAWdio: Hand Input for Mobile VR using Acoustic Sensing

Hand input offers a natural, efficient and immersive form of input for virtual reality (VR), but it has been difficult to implement on mobile VR platforms. Accurate hand-tracking requires a depth sensor and performing computer vision on a smartphone is computationally intensive, which may degrade the frame rate of a VR simulation and drain battery life. PAWdio is a novel 1 degree of freedom (DOF) hand input technique that uses acoustic sensing to track the relative position of an earbud from a headset that the user holds in their hand. PAWdio requires no instrumentation and its low computational overhead assures a high frame rate. A user study with 18 subjects evaluates PAWdio with button input that is commonly available on VR adapters. Results with a 3D target selection task found a similar accuracy and usability, a significantly slower performance, but higher immersion for PAWdio. We discuss limitations and game applications of PAWdio.

Published in the 2016 Annual Symposium on Computer-Human Interaction in Play

Handsfree Omnidirectional VR Navigation using Head Tilt

Navigating mobile virtual reality (VR) is a challenge due to limited input options and/or a requirement for handsfree interaction. Walking-in-place (WIP) is considered to offer a higher presence than controller input but only allows unidirectional navigation in the direction of the user’s gaze–which impedes navigation efficiency. Leaning input enables omnidirectional navigation but currently relies on bulky controllers, which aren’t feasible in mobile VR contexts. This note evaluates the use of head-tilt - implemented using inertial sensing - to allow for handsfree omnidirectional VR navigation on mobile VR platforms. A user study with 24 subjects compared three input methods using an obstacle avoidance navigation task: (1) head-tilt alone (TILT) (2) a hybrid method (WIP-TILT) that uses head tilting for direction and WIP to control speed; and (3) traditional controller input. TILT was significantly faster than WIP-TILT and joystick input, while WIP-TILT and TILT offered the highest presence. There was no difference in cybersickness between input methods.

Published in the Proceedings of the 2017 CHI Conference on Human Factors in Computing Systems

Increasing Walking in VR using Redirected Teleportation

Teleportation is a popular locomotion technique that lets users safely navigate beyond the confines of available positional tracking space without inducing VR sickness. Because available walking space is limited and teleportation is faster than walking, a risk with using teleportation is that users might end up abandoning walking input and only relying on teleportation, which is considered detrimental to presence. We present redirected teleportation; an improved version of teleportation that uses iterative non-obtrusive reorientation and repositioning using a portal to redirect the user back to the center of the tracking space, where available walking space is larger. A user study compares the effectiveness, accuracy, and usability of redirected teleportation with regular teleportation using a navigation task in three different environments. Results show that redirected teleportation allows for a better utilization of available tracking space than regular teleportation, as it requires significantly fewer teleportations, while users walk more and use a larger portion of the available tracking space.

Published in the Proceedings of the 31st Annual ACM Symposium on User Interface Software and Technology

Evaluation of Handsbusy vs Handsfree Virtual Locomotion

To navigate beyond the confines of often limited available positional tracking space, virtual reality (VR) users need to switch from natural walking input to a controller-based locomotion technique, such as teleportation or full locomotion. Overloading the hands with navigation functionality has been considered detrimental to performance given that in many VR experiences, such as games, controllers are already used for tasks, such as shooting or interacting with objects. Existing studies have only evaluated virtual locomotion techniques using a single navigation task. This paper reports on the performance, cognitive load demands, usability, presence and VR sickness occurrence of two hands-busy (full locomotion/teleportation) and two hands-free (tilt/walking-in-place) locomotion methods while participants (n=20) performed a bimanual shooting with navigation task. Though handsfree methods offer a higher presence, they don’t outperform handsbusy locomotion methods in terms of performance.

Published in the Proceedings of the 2018 Annual Symposium on Computer-Human Interaction in Play

Legomotion: Scalable Walking-based Virtual Locomotion

Using real walking for virtual navigation generally delivers the most natural and immersive virtual reality experience, but its usage is generally bounded by available tracking space. To navigate beyond the confines of available tracking space, users need to switch to an artificial locomotion technique, such as controller input. However, having to switch from leg-based input to hand-based input is considered to break presence. We present a hybrid handsfree locomotion technique called legomotion that lets users seamlessly switch between real walking input and walking-in-place input to enable navigation at scale. A user study with 18 participants compared legomotion to full locomotion using a controller. Legomotion led to higher presence as switching to controller input was found to be more tedious. Because controller input is also faster than walking, we observed most users to abandon positional tracking input altogether and primary use a controller for navigation - which then led to a lower presence. This finding could have major implications for the design of VR locomotion.

Published in the Proceedings of the 23rd ACM Symposium on Virtual Reality Software and Technology