Virtual reality (VR) research has provided overviews of locomotion techniques, how they work, their strengths and overall user experience. Considerable research has investigated new methodologies, particularly machine learning to develop redirection algorithms. To best support the development of redirection algorithms through machine learning, we must understand how best to replicate human navigation and behaviour in VR, which can be supported by the accumulation of results produced through live-user experiments. However, it can be difficult to identify, select and compare relevant research without a pre-existing framework in an ever-growing research field. Therefore, this work aimed to facilitate the ongoing structuring and comparison of the VR-based natural walking literature by providing a standardised framework for researchers to utilise. We applied thematic analysis to study methodology descriptions from 140 VR-based papers that contained live-user experiments. From this analysis, we developed the LoCoMoTe framework with three themes: navigational decisions, technique implementation, and modalities. The LoCoMoTe framework provides a standardised approach to structuring and comparing experimental conditions. The framework should be continually updated to categorise and systematise knowledge and aid in identifying research gaps and discussions.

Phantom limb pain is a neuropathic condition in which a person feels pain in a limb that is not present. Cognitive treatments that visually recreate the limb in an attempt to create a cross modal interaction between vision, and touch/proprioception have shown to be effective at alleviating this pain. With improvements in technology, Virtual Mirror Therapy is starting to gain favor, however, there are currently no applications that utilize passive touch in the same way non-virtual reality applications do. This paper investigates whether a visual stimulus can relocate a tactile stimulus to a different location using principles from the rubber hand illusion and mirror therapy. We demonstrate that a displaced visual stimulus in virtual reality can disrupt accurate spatial perception of a physical vibrotactile sensation however the effects are small and require further investigation.

Current Virtual Reality systems only allow users to draw a rectangular perimeter to mark the room-scale area they intend to use. Domestic environments can include furniture and other obstacles that hinder the ease with which users can naturally walk. By leveraging the benefits of passive haptics, users can match physical objects with virtual counterparts, to create substitutional environments. In this paper we explore two visualisation modalities to aid in the creation of a coarse virtual representation of the physical environment, by marking out the volumes of space where physical obstacles are located, to support the substitution process. Our study investigates whether this process is better supported by an inside-looking-out 3D User Interface (that is, viewing the outside world while immersed in Virtual Reality) or from an outside-looking-in one (while viewing the Virtual Environment through an external device, such as a tablet). Results show that the immersive option resulted in better accuracy and was the one with the highest overall preference ratings.

In immersive Virtual Reality systems, users tend to move in a Virtual Environment as they would in an analogous physical environment. In this work, we investigated how user behaviour is affected when the Virtual Environment differs from the physical space. We created two sets of four environments each, plus a virtual replica of the physical environment as a baseline. The first focused on aesthetic discrepancies, such as a water surface in place of solid ground. The second focused on mixing immaterial objects together with those paired to tangible objects. For example, barring an area with walls or obstacles. We designed a study where participants had to reach three waypoints laid out in such a way to prompt a decision on which path to follow based on the conflict between the mismatching visual stimuli and their awareness of the real layout of the room. We analysed their performances to determine whether their trajectories were altered significantly from the shortest route. Our results indicate that participants altered their trajectories in presence of surfaces representing higher walking difficulty (for example, water instead of grass). However, when the graphical appearance was found to be ambiguous, there was no significant trajectory alteration. The environments mixing immaterial with physical objects had the most impact on trajectories with a mean deviation from the shortest route of 60 cm against the 37 cm of environments with aesthetic alterations. The co-existance of paired and unpaired virtual objects was reported to support the idea that all objects participants saw were backed by physical props. From these results and our observations, we derive guidelines on how to alter user movement behaviour in Virtual Environments.