Profiling Distributed Virtual Environments by Tracing Causality

Real-time interactive systems such as virtual environments have high performance requirements, and profiling is a key part of the optimisation process to meet them. Traditional techniques based on metadata and static analysis have difficulty following causality in asynchronous systems. In this paper we explore a new technique for such systems. Timestamped samples of the system state are recorded at instrumentation points at runtime. These are assembled into a graph, and edges between dependent samples recovered. This approach minimises the invasiveness of the instrumentation, while retaining high accuracy. We describe how our instrumentation can be implemented natively in common environments, how its output can be processed into a graph describing causality, and how heterogeneous data sources can be incorporated into this to maximise the scope of the profiling. Across three case studies, we demonstrate the efficacy of this approach, and how it supports a variety of metrics for comprehensively bench-marking distributed virtual environments

Action Sounds Modulate Arm Reaching Movements

Our mental representations of our body are continuously updated through multisensory bodily feedback as we move and interact with our environment. Although it is often assumed that these internal models of body-representation are used to successfully act upon the environment, only a few studies have actually looked at how body-representation changes influence goal-directed actions, and none have looked at this in relation to body-representation changes induced by sound. The present work examines this question for the first time. Participants reached for a target object before and after adaptation periods during which the sounds produced by their hand tapping a surface were spatially manipulated to induce a representation of an elongated arm. After adaptation, participants' reaching movements were performed in a way consistent with having a longer arm, in that their reaching velocities were reduced. These kinematic changes suggest auditory-driven recalibration of the somatosensory representation of the arm morphology. These results provide support to the hypothesis that one's represented body size is used as a perceptual ruler to measure objects' distances and to accordingly guide bodily actions

An ‘In the Wild’ Experiment on Presence and Embodiment using Consumer Virtual Reality Equipment

Consumer virtual reality systems are now becoming widely available. We report on a study on presence and embodiment within virtual reality that was conducted ‘in the wild’, in that data was collected from devices owned by consumers in uncontrolled settings, not in a traditional laboratory setting. Users of Samsung Gear VR and Google Cardboard devices were invited by web pages and email invitation to download and run an app that presented a scenario where the participant would sit in a bar watching a singer. Each participant saw one of eight variations of the scenario: with or without a self-avatar; singer inviting the participant to tap along or not; singer looking at the participant or not. Despite the uncontrolled situation of the experiment, results from an in-app questionnaire showed tentative evidence that a self-avatar had a positive effect on self-report of presence and embodiment, and that the singer inviting the participant to tap along had a negative effect on self-report of embodiment. We discuss the limitations of the study and the platforms, and the potential for future open virtual reality experiments

The Responses of Medical General Practitioners to Unreasonable Patient Demand for Antibiotics - A Study of Medical Ethics Using Immersive Virtual Reality

BACKGROUND: Dealing with insistent patient demand for antibiotics is an all too common part of a General Practitioner's daily routine. This study explores the extent to which portable Immersive Virtual Reality technology can help us gain an accurate understanding of the factors that influence a doctor's response to the ethical challenge underlying such tenacious requests for antibiotics (given the threat posed by growing anti-bacterial resistance worldwide). It also considers the potential of such technology to train doctors to face such dilemmas. EXPERIMENT: Twelve experienced GPs and nine trainees were confronted with an increasingly angry demand by a woman to prescribe antibiotics to her mother in the face of inconclusive evidence that such antibiotic prescription is necessary. The daughter and mother were virtual characters displayed in immersive virtual reality. The specific purposes of the study were twofold: first, whether experienced GPs would be more resistant to patient demands than the trainees, and second, to investigate whether medical doctors would take the virtual situation seriously. RESULTS: Eight out of the 9 trainees prescribed the antibiotics, whereas 7 out of the 12 GPs did so. On the basis of a Bayesian analysis, these results yield reasonable statistical evidence in favor of the notion that experienced GPs are more likely to withstand the pressure to prescribe antibiotics than trainee doctors, thus answering our first question positively. As for the second question, a post experience questionnaire assessing the participants' level of presence (together with participants' feedback and body language) suggested that overall participants did tend towards the illusion of being in the consultation room depicted in the virtual reality and that the virtual consultation taking place was really happening

Head in the Clouds-Floating Locomotion in Virtual Reality

Navigating large virtual spaces within the confines of a small tracked volume in a seated position becomes a serious accessibility issue when users' lower seating position reduces their visibility and makes it uncomfortable to reach for items with ease. Hence, we propose a 'floating' accessibility technique, in which a seated VR user experiences the virtual environment from the perspective of a standing eye height. We conducted a user study comparing sitting, standing and floating conditions and observed that the floating technique had no detrimental effect in comparison to the standing technique and had a slight benefit over the sitting technique

A novel experimental design of a real-time VR tracking device

Virtual Reality (VR) is progressively adopted at different stages of design and product development. Consequently, evolving interaction requirements in engineering design and development for VR are essential for technology adoption. One of these requirements is real-time positional tracking. This paper aims to present an experimental design of a new real-time positional tracking device (tracker), that is more compact than the existing solution, while addressing factors such as wearability and connectivity. We compare the simulation of the proposed device and the existing solution, discuss the results, and the limitations. The new experimental shape of the device is tailored towards research, allowing the engineering designer to take advantage of a new tracker alternative in new ways, and opens the door to new VR applications in research and product development

Immersive competence and immersive literacy: Exploring how users learn about immersive experiences

While immersive experiences mediated through near-eye displays are still a relatively immature medium, there are millions of consumer devices in use. The level of awareness of the forms of the interface and media will vary enormously across the potential audience. Users might own personal devices or might encounter immersive systems in various venues. We introduce the term immersive competence to refer to the general practical knowledge and skills that users accumulate about how typical immersive interfaces work—the ways in which buttons are used, main locomotion techniques, etc. We then introduce the term immersive literacy to refer to awareness of how immersive interfaces are unique, when they might be appropriate, typical forms of media, etc. We sketch out how users develop competence and literacy with immersive media, and then highlight various open questions that are raised

Immersive competence and immersive literacy: Exploring how users learn about immersive experiences

While immersive experiences mediated through near-eye displays are still a relatively immature medium, there are millions of consumer devices in use. The level of awareness of the forms of the interface and media will vary enormously across the potential audience. Users might own personal devices or might encounter immersive systems in various venues. We introduce the term immersive competence to refer to the general practical knowledge and skills that users accumulate about how typical immersive interfaces work—the ways in which buttons are used, main locomotion techniques, etc. We then introduce the term immersive literacy to refer to awareness of how immersive interfaces are unique, when they might be appropriate, typical forms of media, etc. We sketch out how users develop competence and literacy with immersive media, and then highlight various open questions that are raised

Full Body Acting Rehearsal in a Networked Virtual Environment-A Case Study

In order to rehearse for a play or a scene from a movie, it is generally required that the actors are physically present at the same time in the same place. In this paper we present an example and experience of a full body motion shared virtual environment (SVE) for rehearsal. The system allows actors and directors to meet in an SVE in order to rehearse scenes for a play or a movie, that is, to perform some dialogue and blocking (positions, movements, and displacements of actors in the scene) rehearsal through a full body interactive virtual reality (VR) system. The system combines immersive VR rendering techniques as well as network capabilities together with full body tracking. Two actors and a director rehearsed from separate locations. One actor and the director were in London (located in separate rooms) while the second actor was in Barcelona. The Barcelona actor used a wide field-of-view head-tracked head-mounted display, and wore a body suit for real-time motion capture and display. The London actor was in a Cave system, with head and partial body tracking. Each actor was presented to the other as an avatar in the shared virtual environment, and the director could see the whole scenario on a desktop display, and intervene by voice commands. A video stream in a window displayed in the virtual environment also represented the director. The London participant was a professional actor, who afterward commented on the utility of the system for acting rehearsal. It was concluded that full body tracking and corresponding real-time display of all the actors' movements would be a critical requirement, and that blocking was possible down to the level of detail of gestures. Details of the implementation, actors, and director experiences are provided

Ubiq: A System to Build Flexible Social Virtual Reality Experiences

While they have long been a subject of academic study, social virtual reality (SVR) systems are now attracting increasingly large audiences on current consumer virtual reality systems. The design space of SVR systems is very large, and relatively little is known about how these systems should be constructed in order to be usable and efficient. In this paper we present Ubiq, a toolkit that focuses on facilitating the construction of SVR systems. We argue for the design strategy of Ubiq and its scope. Ubiq is built on the Unity platform. It provides core functionality of many SVR systems such as connection management, voice, avatars, etc. However, its design remains easy to extend. We demonstrate examples built on Ubiq and how it has been successfully used in classroom teaching. Ubiq is open source (Apache License) and thus enables several use cases that commercial systems cannot