Locomotion, the ability to walk freely in virtual environments, is a problem with no standardized solution. Walk-in-Place is one strand of solutions in which the user’s physical movement creates forward movement in the virtual environment. This technique is particularly useful for navigation in smartphone-based virtual reality without location detection. However, current mobile implementations use gaze-directed steering which limits the user’s ability to simultaneously scan the environment, which can reduce maneuverability. Additionally, step detection is triggered by head movement which shakes the head-mounted display and can therefore create discomfort and motion sickness. Detached Walk-in-place (dWIP) uses an external gyroscope attached to the body, or held in the hand, to track the user’s body rotation. This detaches the walking direction from gaze direction and removes step detection from the head-mounted-display. In this paper, I present a study of two different dWIP solutions (Torso- and Hand-directed). Both solutions are tested and compared with an existing mobile walk-in-place solution. Performance, user preference and simulator sickness were measured as the participants had to navigate a curved track using each method. The result shows that both dWIP methods required less steps compared with the current WIP, but the torso-directed dWIP is slower compared to the other two. There was no significant difference in user preference or simulator sickness. Overall, dWIP was well received and shows great potential as a mobile VR locomotion method. / Möjligheten att röra sig fritt i virtuella miljöer är ett problem utan en standardiserad lösning. Walk-in-place är en gren av lösningar som innebär att användarens fysiska rörelse skapar framåtrörelse i den virtuella miljön. Den här typen av lösning är speciellt användbar i smartphone-baserade virtuella miljöer utan platsregistrering. Nuvarande walk-in-place implementationer för smartphones använder huvudriktningen för styrning, vilket begränsar användarens förmåga att röra sig och samtidigt överblicka omgivningen, något som kan begränsa manövreringsförmågan. Dessutom triggas stegdetektering av huvudrörelser vilket kan skaka om headsetet och bidra till obehag och illamående. Frikopplad Walk-in-Place (dWIP) använder ett externt gyroskop som sätts fast på kroppen, eller hålls i handen, för att registrera användarens kroppsrotation. Detta frikopplar gångriktningen från huvudriktningen och tar bort stegdetekteringen från headsetet. I den här artikeln presenterar jag en studie av två olika dWIP-lösningar (Kropp- och Handriktad). Båda lösningarna är testade och jämförda med en existerade Walk-in-Place lösning för smartphones. Prestation, preferens och illamående mättes. Studiens deltagare navigerade igenom en böjd bana där de använde alla lösningarna varsin gång. Resultatet visar att deltagarna tog sig igenom banorna på färre steg med båda dWIP-lösningarna jämfört med den nuvarande WIP-lösningen, men att det tog längre tid med kroppsriktad dWIP. Det var ingen signifikant skillnad mellan deltagarnas preferenser eller upplevda illamående. Sammanfattningsvis blev dWIP väl mottaget av deltagarna och visade på en stor potential som navigationsmetod för VR till smartphones.

In the recent years, virtual reality has been used as an effective tool for a wide range of areas such as training, rehabilitation, education and games. The affordability of the new generation headsets helped this medium to become more widespread. However, in order for virtual reality to become mainstream, more content that is specifically designed for this medium is needed. Since virtual reality is a different technology than the computer systems, different design principles may be required for these content for better user experience. One of the crucial components of virtual reality applications is locomotion, since the viewpoint of the user is very important in immersing the users into virtual reality and locomotion is used for moving the viewpoint of user in virtual environments. Locomotion in virtual reality is expected to have a direct effect on user experience in terms of many elements such as effort, enjoyment, frustration, motion sickness and presence. Up to date, many locomotion techniques for virtual reality have been studied in the literature. However, many of these techniques were evaluated in large tracked areas. Although professional motion tracking systems can track large areas, today’s new generation affordable commercial virtual reality systems can only track room scale environments. This dissertation aims at evaluating different locomotion techniques in room scale tracked areas for neurotypical individuals and individuals with ASD. Several previous studies concurred that virtual reality is an effective medium for the training and rehabilitation of individuals with ASD. However, no previous study evaluated locomotion in virtual reality for this specific population. Thus, this dissertation aims at finding out the suitable virtual reality locomotion techniques for individuals with ASD. With these motivations, in this dissertation, locomotion techniques for room scale virtual reality were evaluated under three experiments: virtual reality for vocational rehabilitation system, evaluation of eight virtual reality locomotion techniques, and point & teleport direction specification experiment. In the first experiment of virtual reality for vocational rehabilitation system, locomotion, interaction, and display components in an immersive virtual reality system for vocational rehabilitation was evaluated by 10 neurotypical individuals and 9 individuals with high functioning ASD. The results indicated that neurotypical individuals favored real walking over walk-in-place; tangible interaction over haptic device, touch & snap and touch screen; and head mounted display over curtain screen. For the participants with high functioning ASD, real walking was favored over walk-in-place; touch screen was favored over haptic device, tangible interaction and touch & snap; and curtain screen was favored over head mounted display. In the second experiment, eight virtual reality locomotion techniques were evaluated in a room scale tracked area (2m by 2m). These eight locomotion techniques were: redirected walking, walk-in-place, stepper machine, point & teleport, joystick, trackball, hand flapping and flying. Among these locomotion techniques, the three were commonly used in virtual reality (redirected walking, walk-in-place and joystick), the two were unexplored –explored previously only by a few related studies (stepper machine and point & teleport), and the three were selected and/or modified for individuals with ASD based on their common characteristics (trackball, hand flapping and flying). These eight techniques were evaluated in an immersive virtual reality test environment. A user study was performed with 16 neurotypical participants and 15 participants with high functioning ASD. The results indicated that for neurotypical individuals, point & teleport, joystick and redirected walking were suitable virtual reality locomotion techniques for room scale tracked areas whereas hand flapping and flying were not suitable. For individuals with high functioning ASD, point & teleport, joystick and walk-in-place were suitable virtual reality locomotion techniques for room scale tracked areas whereas hand flapping and flying were not suitable. Locomotion techniques that are similar to point & teleport have been starting to be used in commercial video games, however were not evaluated in the literature. For this reason, a separate experiment was performed as the third experiment to investigate the effects of an additional direction specification component of point & teleport. Since this direction specification component exerted an additional cognitive load into the use of the same technique, which was recommended to be avoided for individuals with ASD in the literature, it was only evaluated by neurotypical individuals. An immersive virtual maze environment was developed and a user study was performed with 16 neurotypical users. The results indicated that the additional direction specification feature did not improve the user experience.