Monte-Carlo Redirected Walking: Gain Selection Through Simulated Walks

We present Monte-Carlo Redirected Walking (MCRDW), a gain selection algorithm for redirected walking. MCRDW applies the Monte-Carlo method to redirected walking by simulating a large number of simple virtual walks, then inversely applying redirection to the virtual paths. Different gain levels and directions are applied, producing differing physical paths. Each physical path is scored and the results used to select the best gain level and direction. We provide a simple example implementation and a simulation-based study for validation. In our study, when compared with the next best technique, MCRDW reduced incidence of boundary collisions by over 50% while reducing total rotation and position gain

Teaching Social Virtual Reality With Ubiq

We share our experiences of teaching virtual reality with Ubiq, an open-source system for building social virtual reality (VR). VR as a subject touches on many areas, including perception, human–computer interaction, and psychology. In our VE module, we consider all aspects of VR. In recent years, networked VR, and in particular social VR, has become increasingly relevant, at the same time as demand for online and hybrid teaching has increased. Commercial social virtual reality systems have proliferated, but for a number of reasons, this has not resulted in systems any more suitable for research and teaching. As a result we created Ubiq, a system for building social VR applications designed first for research and teaching. In this article, we describe how Ubiq came to be, and our experiences of using it in our virtual environments module over the last two years

Comparing Mixed Reality Agent Representations: Studies in the Lab and in the Wild

Mixed-reality systems provide a number of different ways of representing users to each other in collaborative scenarios. There is an obvious tension between using media such as video for remote users compared to representations as avatars. This paper includes two experiments (total n = 80) on user trust when exposed to two of three different user representations in an immersive virtual reality environment that also acts as a simulation of typical augmented reality simulations: full body video, head and shoulder video and an animated 3D model. These representations acted as advisors in a trivia quiz. By evaluating trust through advisor selection and self-report, we found only minor differences between representations, but a strong effect of perceived advisor expertise. Unlike prior work, we did not find the 3D model scored poorly on trust, perhaps as a result of greater congruence within an immersive context

Some Lessons Learned Running Virtual Reality Experiments Out of the Laboratory

In the past twelve months, our team has had to move rapidly from conducting most of our user experiments in a laboratory setting, to running experiments in the wild away from the laboratory and without direct synchronous oversight from an experimenter. This has challenged us to think about what types of experiment we can run, and to improve our tools and methods to allow us to reliably capture the necessary data. It has also offered us an opportunity to engage with a more diverse population than we would normally engage with in the laboratory. In this position paper we elaborate on the challenges and opportunities, and give some lessons learned from our own experience

Ubiq-exp: A toolkit to build and run remote and distributed mixed reality experiments

Developing mixed-reality (MR) experiments is a challenge as there is a wide variety of functionality to support. This challenge is exacerbated if the MR experiment is multi-user or if the experiment needs to be run out of the lab. We present Ubiq-Exp - a set of tools that provide a variety of functionality to facilitate distributed and remote MR experiments. We motivate our design and tools from recent practice in the field and a desire to build experiments that are easier to reproduce. Key features are the ability to support supervised and unsupervised experiments, and a variety of tools for the experimenter to facilitate operation and documentation of the experimental sessions. We illustrate the potential of the tools through three small-scale pilot experiments. Our tools and pilot experiments are released under a permissive open-source license to enable developers to appropriate and develop them further for their own needs

Extending the Open Source Social Virtual Reality Ecosystem to the Browser in Ubiq

Social VR (SVR) systems are VR systems with a common subset of features facilitating unstructured social interaction. In the real world, social situations have many purposes, each with a different set of requirements, and roles its participants take - creator, moderator, performer, visitor, etc. Yet, common SVR systems typically offer only a single client to users. Even if there are versions for different platforms, there is a one-size-fits-all approach to the user experience. Consequently users need to employ workarounds or build their own functionality to support specific roles, where this is possible at all. We argue that platforms need to develop more open frameworks that support different processes and user interactions. One way to do this is through using appropriate web standards and an open messaging system in order to allow distributed clients that can leverage the strongest features of heterogeneous computing platforms. Supporting asymmetrical capabilities greatly increases the scope of supported virtual social interactions and potential use cases of SVR. We take a qualitative experimental approach to exploring cross platform support in this way, from a designers perspective. We use the open-source SDK Ubiq, and create a library that allows building Ubiq Peers using web standards and thus clients that can operate solely in a web browser or certain Javascript environments. We validate our approach by demonstrating six proof of concept demonstrators that would be difficult or impossible to achieve in most other SVR systems, and report on what we encountered for the benefit of other SVR designers

Lessons learnt running distributed and remote mixed reality experiments

One traditional model of research on mixed-reality systems, is the laboratory-based experiment where a number of small variants of a user experience are presented to participants under the guidance of an experimenter. This type of experiment can give reliable and generalisable results, but there are arguments for running experiments that are distributed and remote from the laboratory. These include, expanding the participant pool, reaching specific classes of user, access to a variety of equipment, and simply because laboratories might be inaccessible. However, running experiments out of the laboratory brings a different set of issues into consideration. Here, we present some lessons learnt in running eleven distributed and remote mixed-reality experiments. We describe opportunities and challenges of this type of experiment as well as some technical lessons learnt

Strong gravitational lensing probes of the particle nature of dark matter

There is a vast menagerie of plausible candidates for the constituents of dark matter, both within and beyond extensions of the Standard Model of particle physics. Each of these candidates may have scattering (and other) cross section properties that are consistent with the dark matter abundance, BBN, and the most scales in the matter power spectrum; but which may have vastly different behavior at sub-galactic "cutoff" scales, below which dark matter density fluctuations are smoothed out. The only way to quantitatively measure the power spectrum behavior at sub-galactic scales at distances beyond the local universe, and indeed over cosmic time, is through probes available in multiply imaged strong gravitational lenses. Gravitational potential perturbations by dark matter substructure encode information in the observed relative magnifications, positions, and time delays in a strong lens. Each of these is sensitive to a different moment of the substructure mass function and to different effective mass ranges of the substructure. The time delay perturbations, in particular, are proving to be largely immune to the degeneracies and systematic uncertainties that have impacted exploitation of strong lenses for such studies. There is great potential for a coordinated theoretical and observational effort to enable a sophisticated exploitation of strong gravitational lenses as direct probes of dark matter properties. This opportunity motivates this white paper, and drives the need for: a) strong support of the theoretical work necessary to understand all astrophysical consequences for different dark matter candidates; and b) tailored observational campaigns, and even a fully dedicated mission, to obtain the requisite data.Comment: Science white paper submitted to the Astro2010 Decadal Cosmology & Fundamental Physics Science Frontier Pane

Global assessment of marine plastic exposure risk for oceanic birds

Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species