Object Manipulation in Virtual Reality Under Increasing Levels of Translational Gain

Room-scale Virtual Reality (VR) has become an affordable consumer reality, with applications ranging from entertainment to productivity. However, the limited physical space available for room-scale VR in the typical home or office environment poses a significant problem. To solve this, physical spaces can be extended by amplifying the mapping of physical to virtual movement (translational gain). Although amplified movement has been used since the earliest days of VR, little is known about how it influences reach-based interactions with virtual objects, now a standard feature of consumer VR. Consequently, this paper explores the picking and placing of virtual objects in VR for the first time, with translational gains of between 1x (a one-to-one mapping of a 3.5m*3.5m virtual space to the same sized physical space) and 3x (10.5m*10.5m virtual mapped to 3.5m*3.5m physical). Results show that reaching accuracy is maintained for up to 2x gain, however going beyond this diminishes accuracy and increases simulator sickness and perceived workload. We suggest gain levels of 1.5x to 1.75x can be utilized without compromising the usability of a VR task, significantly expanding the bounds of interactive room-scale VR

Natural locomotion based on a reduced set of inertial sensors: decoupling body and head directions indoors

Inertial sensors offer the potential for integration into wireless virtual reality systems that allow the users to walk freely through virtual environments. However, owing to drift errors, inertial sensors cannot accurately estimate head and body orientations in the long run, and when walking indoors, this error cannot be corrected by magnetometers, due to the magnetic field distortion created by ferromagnetic materials present in buildings. This paper proposes a technique, called EHBD (Equalization of Head and Body Directions), to address this problem using two head- and shoulder-located magnetometers. Due to their proximity, their distortions are assumed to be similar and the magnetometer measurements are used to detect when the user is looking straight forward. Then, the system corrects the discrepancies between the estimated directions of the head and the shoulder, which are provided by gyroscopes and consequently are affected by drift errors. An experiment is conducted to evaluate the performance of this technique in two tasks (navigation and navigation plus exploration) and using two different locomotion techniques: (1) gaze-directed mode (GD) in which the walking direction is forced to be the same as the head direction, and (2) decoupled direction mode (DD) in which the walking direction can be different from the viewing direction. The obtained results show that both locomotion modes show similar matching of the target path during the navigation task, while DD’s path matches the target path more closely than GD in the navigation plus exploration task. These results validate the EHBD technique especially when allowing different walking and viewing directions in the navigation plus exploration tasks, as expected. While the proposed method does not reach the accuracy of optical tracking (ideal case), it is an acceptable and satisfactory solution for users and is much more compact, portable and economical

Locomotion in virtual reality in full space environments

Virtual Reality is a technology that allows the user to explore and interact with a virtual environment in real time as if they were there. It is used in various fields such as entertainment, education, and medicine due to its immersion and ability to represent reality. Still, there are problems such as virtual simulation sickness and lack of realism that make this technology less appealing. Locomotion in virtual environments is one of the main factors responsible for an immersive and enjoyable virtual reality experience. Several methods of locomotion have been proposed, however, these have flaws that end up negatively influencing the experience. This study compares natural locomotion in complete spaces with joystick locomotion and natural locomotion in impossible spaces through three tests in order to identify the best locomotion method in terms of immersion, realism, usability, spatial knowledge acquisition and level of virtual simulation sickness. The results show that natural locomotion is the method that most positively influences the experience when compared to the other locomotion methods.A Realidade Virual é uma tecnologia que permite ao utilizador explorar e interagir com um ambiente virtual em tempo real como se lá estivesse presente. E utilizada em diversas áreas como o entretenimento, educação e medicina devido à sua imersão e capacidade de representar a realidade. Ainda assim, existem problemas como o enjoo por simulação virtual e a falta de realismo que tornam esta tecnologia menos apelativa. A locomoção em ambientes virtuais é um dos principais fatores responsáveis por uma experiência em realidade virtual imersiva e agradável. Vários métodos de locomoção foram propostos, no entanto, estes têm falhas que acabam por influenciar negativamente a experiência. Este estudo compara a locomoção natural em espaços completos com a locomoção por joystick e a locomoção natural em espaços impossíveis através de três testes de forma a identificar qual o melhor método de locomoção a nível de imersão, realismo, usabilidade, aquisição de conhecimento espacial e nível de enjoo por simulação virtual. Os resultados mostram que a locomoção natural é o método que mais influencia positivamente a experiência quando comparado com os outros métodos de locomoção

Advancing proxy-based haptic feedback in virtual reality

This thesis advances haptic feedback for Virtual Reality (VR). Our work is guided by Sutherland's 1965 vision of the ultimate display, which calls for VR systems to control the existence of matter. To push towards this vision, we build upon proxy-based haptic feedback, a technique characterized by the use of passive tangible props. The goal of this thesis is to tackle the central drawback of this approach, namely, its inflexibility, which yet hinders it to fulfill the vision of the ultimate display. Guided by four research questions, we first showcase the applicability of proxy-based VR haptics by employing the technique for data exploration. We then extend the VR system's control over users' haptic impressions in three steps. First, we contribute the class of Dynamic Passive Haptic Feedback (DPHF) alongside two novel concepts for conveying kinesthetic properties, like virtual weight and shape, through weight-shifting and drag-changing proxies. Conceptually orthogonal to this, we study how visual-haptic illusions can be leveraged to unnoticeably redirect the user's hand when reaching towards props. Here, we contribute a novel perception-inspired algorithm for Body Warping-based Hand Redirection (HR), an open-source framework for HR, and psychophysical insights. The thesis concludes by proving that the combination of DPHF and HR can outperform the individual techniques in terms of the achievable flexibility of the proxy-based haptic feedback.Diese Arbeit widmet sich haptischem Feedback für Virtual Reality (VR) und ist inspiriert von Sutherlands Vision des ultimativen Displays, welche VR-Systemen die Fähigkeit zuschreibt, Materie kontrollieren zu können. Um dieser Vision näher zu kommen, baut die Arbeit auf dem Konzept proxy-basierter Haptik auf, bei der haptische Eindrücke durch anfassbare Requisiten vermittelt werden. Ziel ist es, diesem Ansatz die für die Realisierung eines ultimativen Displays nötige Flexibilität zu verleihen. Dazu bearbeiten wir vier Forschungsfragen und zeigen zunächst die Anwendbarkeit proxy-basierter Haptik durch den Einsatz der Technik zur Datenexploration. Anschließend untersuchen wir in drei Schritten, wie VR-Systeme mehr Kontrolle über haptische Eindrücke von Nutzern erhalten können. Hierzu stellen wir Dynamic Passive Haptic Feedback (DPHF) vor, sowie zwei Verfahren, die kinästhetische Eindrücke wie virtuelles Gewicht und Form durch Gewichtsverlagerung und Veränderung des Luftwiderstandes von Requisiten vermitteln. Zusätzlich untersuchen wir, wie visuell-haptische Illusionen die Hand des Nutzers beim Greifen nach Requisiten unbemerkt umlenken können. Dabei stellen wir einen neuen Algorithmus zur Body Warping-based Hand Redirection (HR), ein Open-Source-Framework, sowie psychophysische Erkenntnisse vor. Abschließend zeigen wir, dass die Kombination von DPHF und HR proxy-basierte Haptik noch flexibler machen kann, als es die einzelnen Techniken alleine können

Humans plan for the near future to walk economically on uneven terrain

Humans experience small fluctuations in their gait when walking on uneven terrain. The fluctuations deviate from the steady, energy-minimizing pattern for level walking, and have no obvious organization. But humans often look ahead when they walk, and could potentially plan anticipatory fluctuations for the terrain. Such planning is only sensible if it serves some an objective purpose, such as maintaining constant speed or reducing energy expenditure, that is also attainable within finite planning capacity. Here we show that humans do plan and perform optimal control strategies on uneven terrain. Rather than maintain constant speed, they make purposeful, anticipatory speed adjustments that are consistent with minimizing energy expenditure. A simple optimal control model predicts economical speed fluctuations that agree well with experiments with humans (N = 12) walking on seven different terrain profiles (correlated with model r = 0.517 std. 0.109, P < 0.05 all terrains). Participants made repeatable speed fluctuations starting about seven to eight steps ahead of each terrain feature (up to 7.5 cm height difference each step, up to 16 consecutive features). They need not plan farther ahead, because each leg collision with ground dissipates energy, preventing momentum from persisting indefinitely. About seven to eight steps of continuous look-ahead and working memory thus suffice to practically optimize for any length of terrain. Humans reason about walking in the near future to plan complex optimal control sequences.Comment: 17 pages, 8 figure

Laughing Out Loud: Humor Usage in Young Childhood Classrooms

The purpose of this honors thesis is to document the types of humorous occurrences among 2-3-yearold children and then to describe the relationship between children’s humor during circle time and teacher-child interactions, noting how teachers respond to these humorous occurrences. I conducted my observations at the Child Study Development Center in the Nursery II classroom, which included one head teacher and 19 children. I audiotaped and photographed my observations and took notes on two tables. One table included recording linguistic humor and non-linguistic humor occurrences, or humor involving words and humor involving movement, and the other table included teacher responses to humorous occurrences (Craig-Unkefer & Fitzgerald, 2008). My findings show that the majority of humorous occurrences stem from children’s incongruent body movements and group discussion during story time. Furthermore, when the teacher extends or scaffolds a humorous occurrence, there is whole-group discussion with attentive listening from children. When a teacher rejects or ignores humor, the humor either stops or the behavior is labeled as inappropriate by the teacher and the children are redirected to what is expected of them. I discuss why humor in the classroom is important for educators to use to enhance young children’s learning

Empathy in the design of assistive devices for older adults: An exploratory study with Portuguese women

Assistive Devices (AD) aim to enhance the autonomy of their users, among whom are older adults. However, older adults often have negative feelings towards these products, such as the fear of dependence, which in turn influence their acceptance and use. These feelings can result from the use of design approaches that focus merely on users’ physical abilities. This article argues for the importance of rethinking approaches to the design of AD by focusing on a holistic and empathic view of older people. It also seeks to contribute to a richer understanding of what independence and dependence means to older people. This article describes an exploratory study with eleven older women, living in two distinct contexts in the north of Portugal – rural and urban. The qualitative data that emerged from this research were used to develop five empirical personas, to provide a readily usable and useful tool for design

Charting the Course: Legal Help for Nonprofits in Troubled Times

As the recession spread worldwide in the fall of 2008, many nonprofit organizations in New York and across the United States faced major operating stresses that jeopardized their programs and disrupted their plans. As the impact of the economic downturn on the nonprofit sector deepened, an increasing number of the nation's 1.6 million nonprofit organizations changed their budgets, structures, and activities to strive for stability. More than four years later, most organizations are operating with a revised set of assumptions, procedures, and partners. Decreased cash flow, exacerbated by an increased demand for services, has trapped the nonprofit sector in a constant state of financial strain. At stake is not only the viability of particular organizations and their employees, but also the millions of people who are the beneficiaries of their services.The report, Charting the Course, identifies steps that nonprofit organizations can take to address the economic issues affecting the sector nationwide, while focusing on data and examples from New York City's nonprofit sector. It draws upon national and local studies for factual data about economy-related stresses affecting the nonprofit sector. It gives special attention to the experiences of human services, economic development, and community based organizations for two reasons. Those organizations often have roots in the neighborhoods where their low-income constituents live, making their safety net services vital when an economic crisis leaves millions of Americans unemployed and underemployed. Moreover, many of these organizations rely heavily on state and local government funding, so state and local government budget cuts greatly endanger their programs

The Cowl - v.79 - n.12 - Dec 4, 2014

The Cowl - student newspaper of Providence College. Vol 79 - No. 12 - December 4, 2014. 24 pages