Walking-based locomotion techniques in virtual reality (VR) can use redirection to enable walking in a virtual environment larger than the physical one. This results in a mismatch between the perceived virtual and physical movement, which is known to cause VR sickness. However, it is unclear if different types of walking techniques (e.g., resetting, reorientation, or self-overlapping spaces) affect VR sickness differently. To address this, we conducted a systematic review and meta-analysis of 96 papers published in 2016–2022 that measure VR sickness in walking-based locomotion. We find different VR sickness effects between types of redirection and between normal walking and redirection. However, we also identified several problems with the use and reporting of VR sickness measures. We discuss the challenges in understanding VR sickness differences between walking techniques and present guidelines for measuring VR sickness in locomotion studies.

When using tangible props as proxies for virtual objects, it is important that these haptic proxies are similar to and co-located with their virtual counterparts. This makes it challenging to scale virtual scenarios because more proxies are needed as scenarios grow more complex. Haptic retargeting, or virtual remapping, makes it possible to repurpose the same physical prop as a proxy for multiple virtual objects. This paper details a user study comparing two techniques for repurposing haptic proxies; namely haptic retargeting based on body warping and change blindness remapping. Participants performed a simple button-pressing task, and 24 virtual buttons were mapped onto four haptic proxies with varying degrees of misalignment. Body warping and change blindness remapping were used to realign the real and virtual buttons, and the results indicate that users failed to reliably detect realignment of up to 7.9 cm for body warping and up to 9.7 cm for change blindness remapping. Moreover, change blindness remapping yielded significantly higher self-reported agency, and marginally higher ownership. Taken together these results suggest that this less explored technique has potential when it comes to repurposing haptic proxies for virtual reality.

This paper details preliminary explorations of how cutaneous rabbit illusions and virtual reality can be combined to produce experiences of cutaneous saltation along paths that do not match the actuator configuration, and to reduce the number of needed actuators. We present two studies exploring the effects of actuator configuration, vibration properties, and varying visual presentations of the virtual object touching the user’s forearm. The results indicate that the illusion can occur along a curvilinear path, and congruent visual movement can enhance the illusion and potentially reduce the number of needed actuators. Incongruent visual movement does not break the illusion but appears to modulate the perceived path of the virtual object.

When physical props serve as proxies for virtual tools used to manipulate the virtual environment, it is challenging to provide appropriate haptic feedback. Redirected tool-mediated manipulation addresses this challenge by distorting the mapping between physical and virtual tools to provide a sensation of manipulating the virtual environment, when the physical tool comes into contact with another physical prop. For example, a virtual hammer's position can be offset to ensure that physical impacts accompany each strike of a virtual nail. We demonstrate the idea by showing that it can be used to create sensations of impact and resistance when driving a virtual nail into a surface, when tightening a virtual screw, and when sawing through a virtual plank. The results of a user study indicate that the proposed approach is perceived as more realistic than interaction with a single physical prop or controller and no notable detriments to precision were observed.

Manipulating the appearance of a Virtual Environment to enable natural walking has so far focused on modifications that are intended to be unnoticed by users. In our research, we took a radically different approach by embracing the overt nature of the change. To explore this method, we designed the Space Bender, a natural walking technique for room-scale VR. It builds on the idea of overtly manipulating the Virtual Environment by "bending" the geometry whenever the user comes in proximity of a physical boundary. Our aim was to evaluate the feasibility of this approach in terms of performance and subjective feedback. We compared the Space Bender to two other similarly situated techniques: Stop and Reset and Teleportation, in a task requiring participants to traverse a 100 m path. Results show that the Space Bender was significantly faster than Stop and Reset, and preferred to the Teleportation technique, highlighting the potential of overt manipulation to facilitate natural walking.

Directivity and gain in microphone array systems for hearing aids or hearable devices allow users to acoustically enhance the information of a source of interest. This source is usually positioned directly in front. This feature is called acoustic beamforming. The current study aimed to improve users' interactions with beamforming via a virtual prototyping approach in immersive virtual environments (VEs). Eighteen participants took part in experimental sessions composed of a calibration procedure and a selective auditory attention voice-pairing task. Eight concurrent speakers were placed in an anechoic environment in two virtual reality (VR) scenarios. The scenarios were a purely virtual scenario and a realistic 360° audio-visual recording. Participants were asked to find an individual optimal parameterization for three different virtual beamformers: (i) head-guided, (ii) eye gaze-guided, and (iii) a novel interaction technique called dual beamformer, where head-guided is combined with an additional hand-guided beamformer. None of the participants were able to complete the task without a virtual beamformer (i.e., in normal hearing condition) due to the high complexity introduced by the experimental design. However, participants were able to correctly pair all speakers using all three proposed interaction metaphors. Providing superhuman hearing abilities in the form of a dual acoustic beamformer guided by head and hand movements resulted in statistically significant improvements in terms of pairing time, suggesting the task-relevance of interacting with multiple points of interests.

The poster describes a multisensory simulation of plucking guitar strings in virtual reality and a user study evaluating the simulation. Auditory feedback is generated by a physics-based simulation of guitar strings, and haptic feedback is provided by a combination of high fidelity vibrotactile actuators and a Phantom Omni. The study compared four conditions: no haptic feedback, vibrotactile feedback, force feedback, and a combination of force and vibrotactile feedback. The results indicate that the combination of vibrotactile and force feedback elicits the most realistic experience, and during this condition, participants were less likely to inadvertently hit strings. Notably, no significant differences were found between the conditions involving either vibrotactile or force feedback.

Being able to hear objects in an environment, for example using echolocation, is a challenging task. The main goal of the current work is to use virtual environments (VEs) to train novice users to navigate using echolocation. Previous studies have shown that musicians are able to differentiate sound pulses from reflections. This paper presents design patterns for VE simulators for both training and testing procedures, while classifying users' navigation strategies in the VE. Moreover, the paper presents features that increase users' performance in VEs. We report the findings of two user studies: a pilot test that helped improve the sonic interaction design, and a primary study exposing participants to a spatial orientation task during four conditions which were early reflections (RF), late reverberation (RV), early reflections-reverberation (RR) and visual stimuli (V). The latter study allowed us to identify navigation strategies among the users. Some users (10/26) reported an ability to create spatial cognitive maps during the test with auditory echoes, which may explain why this group performed better than the remaining participants in the RR condition.

This poster describes a within-subject study of the virtual body ownership (VBO) illusion using anatomically similar but morphologically different body of a virtual bat. Participants experienced visuo-tactile stimulation of their arms while seeing an object touching the wing of the bat. The mapping between the real and the virtual touch points varied across three conditions: no spatial deviation between visual and tactile input, 50% deviation, and 70% deviation. The results suggest that the degree of experienced VBO varies across the conditions. The illusion was broken in the absence of visuo-tactile stimuli.

This poster describes a within-subject study of agency's influence on virtual body ownership (VBO) using anatomically similar but morphologically different body of a virtual bat. Paricipants were exposed to flight under four conditions: voluntary movement through virtual environment (VE) with avatar present, voluntary movement through virtual environment (VE) with avatar absent, voluntary limbs movement without movements through VE, and finally involuntary movement of the avatar through VE. The results suggest that agency enhances VBO illusion the most under participants' full control during flight locomotion.

This poster details the design and evaluation of Locomotion3- a framework that allows users to freely alternate between real walking, walking-in-place (WIP), and a skateboard metaphor depending on whether navigation requires efficiency, precision, or both. The user study compared the framework to WIP locomotion and the skateboard metaphor and found that Locomotion3achieves a balance between the efficiency of the skateboard metaphor and the precision of WIP locomotion.

Most virtual reality (VR) applications require the user to travel through the virtual environment (VE). However, some users are susceptible to cybersickness, and this issue is particularly prominent if the user is physically stationary while virtually moving. One approach to minimizing cybersickness is to rotate the user in discrete steps. This poster presents a between-subjects study (n=42) comparing this approach to smooth virtual rotation. The results revealed a statistically significant increase in self-reported sickness after exposure to the VE in case of both conditions. No statistically significant differences between the two conditions were found.

Walking-in-place (WIP) techniques provide users with a relatively natural way of walking in virtual reality. However, previous research has primarily focused on WIP during forward movement and tasks involving turning. Thus, little is known about what gestures to use in combination with WIP in order to enable sidestepping. This paper presents two user studies comparing three different types of gestures based on movement of the hip, leaning of the torso, and actual sidesteps. The first study focuses on purely lateral movement while the second involves both forward and lateral movement. The results of both studies suggest that leaning yielded significantly more natural walking experiences and this gesture also produced significantly less positional drift.

This poster describes a between-groups study (n=24) exploring the use of virtual reality (VR) for facilitating focused meditation. Half of the participants were exposed to a meditation session combing the sound of a guiding voice and a visual environment including virtual objects for the participants to focus on. The other half of the participants were only exposed to the auditory guide. The participants' experience of the sessions was assessed using self-reported measures of perceived concentration, temporal duration, stress reduction, and comfort. Interestingly, no statistically significant differences were found between the two conditions. This finding may be revealing in regards to the usefulness of VR-based meditation.

This poster describes a within-groups study (n=17) comparing participants' experience of three different input conditions for instigating virtual teleportation (button clicking, physical jumping, and fist clenching). The results indicated that teleportation by clicking a button generally required less explicit attention and was perceived as more enjoyable, less disorienting, and less physically demanding.

Previous research on visual realism and presence has not involved scenarios, graphics, and hardware representative of commercially available VR games. This poster details a between-subjects study (n=50) exploring if polygon count and texture resolution influence presence during exposure to a VR game. The results suggest that a higher polygon count and texture resolution increased presence as assessed by means of self-reports and physiological measures.

In this paper we propose an experiment that evaluates the influence of audience noise on the feeling of presence and the perceived quality in a virtual reality concert experience delivered using Wave Field Synthesis. A 360 degree video of a live rock concert from a local band was recorded. Single sound sources from the stage and the PA system were recorded, as well as the audience noise, and impulse responses of the concert venue. The audience noise was implemented in the production phase. A comparative study compared an experience with and without audience noise. In a between subject experiment with 30 participants we found that audience noise does not have a significant impact on presence. However, qualitative evaluations show that the naturalness of the sonic experience delivered through wavefield synthesis had a positive impact on the participants.

In this paper we present a within-subjects study (n=26) comparing participants' experience of three kinds of haptic feedback (no haptic feedback, low fidelity haptic feedback and high fidelity haptic feedback) simulating the impact between a virtual baseball bat and ball. We noticed some minor effect on high fidelity versus low fidelity haptic feedback, but haptic feedback generally enhanced realism and quality of experience.

The advent of affordable virtual reality (VR) displays and 360° video cameras has sparked an interest in bringing cinematic experiences from the screen and into VR. However, it remains uncertain whether traditional approaches to filmmaking can be directly applied to cinematic VR. Historically editing has provided filmmakers with a powerful tool for shaping stories and guiding the attention of audiences. However, will an immersed viewer, experiencing the story from inside the fictional world, find cuts disorienting? This paper details two studies exploring how cut frequency influences viewers' sense of disorientation and their ability to follow the story, during exposure to fictional 360° films experienced using a head-mounted display. The results revealed no effects of increased cut frequency which leads us to conclude that editing need not pose a problem in relation to cinematic VR, as long as the participants' attention is appropriately guided at the point of the cut.

This poster details a within-subjects study (n=17) investigating the effects of vibrotactile stimulation on illusory self-motion, presence and perceived realism during an interactive sandboarding simulation. The study compared three conditions: no vibration, constant vibration and dynamic vibration. The results suggest that constant vibrotactile feedback led to significantly more compelling self-motion illusions and a higher degree of perceived realism.

This study investigates sliding as a walking-in-place (WIP) method for virtual reality navigation using the Wizdish. The Wizdish is a novel WIP device built for home usage. Two WIP methods, sliding and marching, were compared for naturalness, presence, and surface difference. The sliding technique used on the Wizdish was found to be significantly more disruptive during the experience compared to marching. This could be due to the size of the Wizdish, restricting the users stride, or due to a longer acclimatization time.

Redirection techniques allow users to explore large virtual environments on foot while remaining within a limited physical space. However, research has primarily focused on redirection through manipulation of the visuals used to represent the virtual environment. We describe a within-subjects study (n=31) exploring if participants' ability to detect differences between real and virtual rotations is influenced by the addition of sound that is spatially aligned with its virtual source. The results revealed similar detection thresholds for conditions involving moving audio, static audio, and no audio. This may be viewed as an indication of visual dominance during scenarios such as the one used for the current study.

In virtual reality environments that allow users to walk freely, the area of the virtual environment (VE) is constrained to the size of the tracking area. By using redirection techniques, this problem can be partially circumvented; one of the techniques involves rotating the user more or less in the virtual world than in the physical world; this technique is referred to as rotational gain. Experiments conducted by Frank Steinicke et al. [7] sought to uncover users' ability to detect the usage of rotational gain. This paper seeks to further investigate this area, examining the effect of visual density in the VE. Testing visual density using 0, 4 and 16 objects did not seem to reveal the point at which the test participants become noticeably affected.

This paper presents two within-subjects studies (n=23) exploring how different combinations of visual and auditory feedback influence perceived realism, virtual self-perception and the experience of safety during walks on a virtual platform suspended over a canyon. In the first study, the frequency factor of the footstep sounds was altered and the visual appearance was changed between a newly built wooden bridge and an old bridge with a weaker structure and broken planks. In the second study, the sounds of creaking wood were added to the footstep sounds in half of the trails and compared against footsteps without creaking sounds. Moreover, the frequency factor of the frequency controls for footsteps was also manipulated between trails, but the visual appearance of the bridge was limited to the model of the old broken bridge.

Recent technological advances have brought Virtual Reality (VR) into the homes of consumers, and there is a growing interest in bringing cinematic experiences from the screen and into VR. However, cinematic VR limits filmmakers' ability to effectively guide the audience's attention. In this paper we present a taxonomy of approaches to guiding users' attention, and present a study comparing two such approaches with a control condition devoid of guidance. One approach guides users by controlling their body's orientation, and the other implicitly directs their attention by encouraging them to follow a firefly with their gaze. The results revealed interesting, albeit statistically insignificant, indications that assuming control of the user's action may negatively influence presence, whereas the firefly was perceived as significantly more helpful.

In this paper we describe an experiment aiming to investigate the impact of auditory feedback in a virtual reality supermarket scenario. The participants were asked to read a shopping list and collect items one by one and place them into a shopping cart. Three conditions were presented randomly, where audio feedback was (1) absent, (2) had impact sounds for collisions including when grasping, (3) had impact sounds as well as continuous sounds when moving the products. The subjects experience of the simulation during the three experimental conditions were studied using a questionnaire where ratings on presence, body ownership, awareness of own movements, usability and enjoyment were collected. The results are presented and discussed.

Individuals tend to find realistic walking speeds too slow when relying on treadmill walking or Walking-In-Place (WIP) techniques for virtual travel. This paper details three studies investigating the effects of visual display properties and gain presentation mode on the perceived naturalness of virtual walking speeds: The first study compared three different degrees of peripheral occlusion; the second study compared three different degrees of perceptual distortion produced by varying the geometric field of view (GFOV); and the third study compared three different ways of presenting visual gains. All three studies compared treadmill walking and WIP locomotion. The first study revealed no significant main effects of peripheral occlusion. The second study revealed a significant main effect of GFOV, suggesting that the GFOV size may be inversely proportional to the degree of underestimation of the visual speed. The third study found a significant main effect of gain presentation mode. Allowing participants to interactively adjust the gain led to a smaller range of perceptually natural gains and this approach was significantly faster. However, the efficiency may come at the expense of confidence. Generally the lower and upper bounds of the perceptually natural speeds were higher for treadmill walking than WIP. However, not all differences were statistically significant.

This poster details a study investigating the effect of Head Mounted Display (HMD) weight and locomotion method (Walking-In-Place and treadmill walking) on the perceived naturalness of virtual walking speeds. The results revealed significant main effects of movement type, but no significant effects of HMD weight were identified.

Walking-In-Place (WIP) techniques make relatively natural walking experiences within immersive virtual environments possible when the physical interaction space is limited in size. In order to facilitate such experiences it is necessary to establish a natural connection between steps in place and virtual walking speeds. This paper details a study investigating the effects of movement type (treadmill walking and WIP) and step frequency (1.4, 1.8 and 2.2 steps per second) on the range of perceptually natural visual walking speeds. The results suggests statistically significant main effects of both movement type and step frequency but no significant interaction between the two variables.

Walking-In-Place (WIP) techniques make it possible to facilitate relatively natural locomotion within immersive virtual environments that are larger than the physical interaction space. However, in order to facilitate natural walking experiences one needs to know how to map steps in place to virtual motion. This paper describes two within-subjects studies performed with the intention of establishing the range of perceptually natural walking speeds for WIP locomotion. In both studies, subjects performed a series of virtual walks while exposed to visual gains (optic flow multipliers) ranging from 1.0 to 3.0. Thus, the slowest speed was equal to an estimate of the subjects normal walking speed, while the highest speed was three times greater. The perceived naturalness of the visual speed was assessed using self-reports. The first study compared four different types of movement, namely, no leg movement, walking on a treadmill, and two forms of gestural input for WIP locomotion. The results suggest that WIP locomotion is accompanied by a perceptual distortion of the speed of optic flow. The second study was performed using a 4×2 factorial design and compared four different display field-of-views (FOVs) and two types of movement, walking on a treadmill and WIP locomotion. The results revealed significant main effects of both movement type and field of view, but no significant interaction between the two variables. Particularly, they suggest that the size of the display FOV is inversely proportional to the degree of underestimation of the virtual speeds for both treadmill-mediated virtual walking and WIP locomotion. Combined, the results constitute a first attempt at establishing a set of guidelines specifying what virtual walking speeds WIP gestures should produce in order to facilitate a natural walking experience.

Walking-In-Place (WIP) techniques have potential in terms of solving the problem arising when an immersive virtual environment offers a larger freedom of movement than the physical environment. Such techniques are particularly useful when the spatial constraints are very prominent, as they are likely to be in relation to immersive gaming systems located in the homes of consumers. However, most existing WIP techniques rely on movement of the legs which may cause users, wearing a head mounted display, to unintentionally move. This paper details a within-subjects study performed with the intention of investigating how two alternative types of gestural input relying on arm and hip movements compare to the traditional WIP gesture and keyboard input. Visual feedback was delivered through a head-mounted display and auditory feedback was provided by means of a 16-channel surround sound system. The gestures were evaluated in terms of perceived naturalness, presence and real world positional drift. The results suggest that both WIP and arm swinging are perceived as significantly more natural than hip movement and the keyboard configuration. However, arm swinging better matched real walking in terms of energy expenditure and led to significantly less positional drift.

Walking-In-Place interaction techniques seem particularly useful in relation to immersive virtual environments where the user's movement is greatly constrained by a limited physical space. However, current techniques may not be particularly useful in combination with head-mounted displays since many users unintentionally move forward while walking in place. We refer to this phenomenon accidental movement as Unintended Positional Drift. The poster presents evidence of the phenomenon's existence and subsequently discusses different design solutions which potentially could circumvent the problem.

We describe two psychophysical experiments where we have quantified how much humans can unknowingly be redirected by auditory stimuli. The experiments use a two-alternative-forced-choice task. We tested 19 subjects in two different experiments: (E1) discrimination between virtual and physical rotation, and (E2) discrimination of path curvature. In experiment E1 subjects performed rotations with different gains, and then had to choose whether the auditory perceived rotation was smaller or greater than the physical rotation. In experiment E2 subjects estimate the path curvature when walking a curved path in the real world while the visual display shows a straight path in the virtual world. Our results show that users can be turned physically about 20% percent more or 12% less than the perceived virtual rotation, and users can be redirected on a circular arc while they believe they are walking straight.

In this paper we describe an experiment whose goal is to investigate the role of physics-based auditory and haptic feedback provided at feet level to enhance realism in a virtual environment. To achieve this goal, we designed a multimodal virtual environment where subjects could walk on a platform overlooking a canyon. Subjects were asked to visit the environment wearing an head-mounted display and a custom made pair of sandals enhanced with sensors and actuators. A 12-channels surround sound system delivered a soundscape which was consistent with the visual environment. Passive haptics was provided by having a physical wooden platform present in the laboratory. Subjects reported of having a more realistic experience while auditory and haptic feedback are present. However, measured physiological data and post-experimental presence questionnaire do not show significant differences when audio-haptic feedback is provided.