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

LoCoMoTe – a framework for classification of natural locomotion in VR by task, technique and modality

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

Spatial cognitive implications of user interfaces in virtual reality and route guidance

The relationship between spatial learning and technology is becoming more intimately intertwined. This dissertation explores that relationship with multiple technologies and multiple types of spatial knowledge. With virtual reality, teleporting is commonly used to explore large-scale virtual environments when users are limited by the tracked physical space. Past work has shown that locomotion interfaces such as teleporting have spatial cognitive costs associated with the lack of accompanying self-motion cues for small-to-medium scale movement in virtual environments, but less is known about whether the spatial cognitive costs extend to learning a large-scale virtual environment. Experiment 1 (Chapter 2) evaluates whether rotational self-motion cues teleporting interfaces impact spatial learning for large-scale virtual environments. using two measures of survey learning (an object-to-object pointing task and map drawing task). Results indicate that access to rotational self-motion cues when teleporting led to more accurate survey representations of large-scale virtual environments. Therefore, virtual reality developers should strongly consider the benefits of rotational self-motion cues when creating locomotion interfaces. For Experiments 2 and 3 (Chapter 3), previous work has demonstrated that repeatedly using GPS route guidance reliably diminishes route learning. Memory research has shown that recalling information (i.e., testing) significantly improves retention of that information when compared to restudying the same information. Similarly, memory retrieval of routes during learning may be advantageous for long-term retention compared to following route guidance using a GPS. However, whether such a benefit would occur for route learning is not clear because the benefits of testing have primarily been explored with verbal materials. Experiments 2 and 3 explore whether retrieving routes from memory during learning enhance route knowledge of a large-scale virtual city using a driving simulator compared to learning a route by repeatedly following GPS route guidance. Results from both experiments demonstrated that there was no difference in performance between testing and repeatedly following route guidance at final test, but further analysis revealed that in the testing condition, a large proportion of errors produced during learning was also repeated at final test. The experiments described here not only expand the current knowledge regarding the intersection of technology and spatial learning, but also underscore the importance of evaluating applications of spatial cognitive theory across a range of applied domains

Towards Understanding and Expanding Locomotion in Physical and Virtual Realities

Among many virtual reality interactions, the locomotion dilemma remains a significant impediment to achieving an ideal immersive experience. The physical limitations of tracked space make it impossible to naturally explore theoretically boundless virtual environments with a one-to-one mapping. Synthetic techniques like teleportation and flying often induce simulator sickness and break the sense of presence. Therefore, natural walking is the most favored form of locomotion. Redirected walking offers a more natural and intuitive way for users to navigate vast virtual spaces efficiently. However, existing techniques either lead to simulator sickness due to visual and vestibular mismatch or detract users from the immersive experience that virtual reality aims to provide. This research presents innovative techniques and applications to enhance the user experience by expanding walkable, physical space in Virtual Reality. The thesis includes three main contributions. The first contribution proposes a mobile application that uses markerless Augmented Reality to allow users to explore a life-sized virtual library through a divide-and-rule approach. The second contribution presents a subtle redirected walking technique based on inattentional blindness, using dynamic foveated rendering and natural visual suppressions like blinks and saccades. Finally, the third contribution introduces a novel redirected walking solution that leverages a deep neural network, to predict saccades in real-time and eliminate the hardware requirements for eye-tracking. Overall, this thesis offers valuable contributions to human-computer interaction, investigating novel approaches to solving the locomotion dilemma. The proposed solutions were evaluated through extensive user studies, demonstrating their effectiveness and applicability in real-world scenarios like training simulations and entertainment

DeFINE: Delayed Feedback based Immersive Navigation Environment for Studying Goal-Directed Human Navigation

With the advent of consumer-grade products for presenting an immersive virtual environment (VE), there is a growing interest in utilizing VEs for testing human navigation behavior. However, preparing a VE still requires a high level of technical expertise in computer graphics and virtual reality, posing a significant hurdle to embracing the emerging technology. To address this issue, this paper presents Delayed Feedback based Immersive Navigation Environment (DeFINE), a framework that allows for easy creation and administration of navigation tasks within customizable VEs via intuitive graphical user interfaces and simple settings files. Importantly, DeFINE has a built-in capability to provide performance feedback to participants during an experiment, a feature that is critically missing in other similar frameworks. To show the usability of DeFINE from both experimentalists' and participants' perspectives, a demonstration was made in which participants navigated to a hidden goal location with feedback that differentially weighted speed and accuracy of their responses. In addition, the participants evaluated DeFINE in terms of its ease of use, required workload, and proneness to induce cybersickness. The demonstration exemplified typical experimental manipulations DeFINE accommodates and what types of data it can collect for characterizing participants' task performance. With its out-of-the-box functionality and potential customizability due to open-source licensing, DeFINE makes VEs more accessible to many researchers.Comment: 43 pages, 10 figures, 5 tables, Submitted to Behavioral Research Method

An evaluation testbed for locomotion in virtual reality

A common operation performed in Virtual Reality (VR) environments is locomotion. Although real walking can represent a natural and intuitive way to manage displacements in such environments, its use is generally limited by the size of the area tracked by the VR system (typically, the size of a room) or requires expensive technologies to cover particularly extended settings. A number of approaches have been proposed to enable effective explorations in VR, each characterized by different hardware requirements and costs, and capable to provide different levels of usability and performance. However, the lack of a well-defined methodology for assessing and comparing available approaches makes it difficult to identify, among the various alternatives, the best solutions for selected application domains. To deal with this issue, this paper introduces a novel evaluation testbed which, by building on the outcomes of many separate works reported in the literature, aims to support a comprehensive analysis of the considered design space. An experimental protocol for collecting objective and subjective measures is proposed, together with a scoring system able to rank locomotion approaches based on a weighted set of requirements. Testbed usage is illustrated in a use case requesting to select the technique to adopt in a given application scenario

VR Lab: User Interaction in Virtual Environments using Space and Time Morphing

Virtual Reality (VR) allows exploring changes in space and time that would otherwise be difficult to simulate in the real world. It becomes possible to transform the virtual world by increasing or diminishing distances or playing with time delays. Analysing the adaptability of users to different space-time conditions allows studying human perception and finding the right combination of interaction paradigms. Different methods have been proposed in the literature to offer users intuitive techniques for navigating wide virtual spaces, even if restricted to small physical play areas. Other studies investigate latency tolerance, suggesting humans’ inability to detect slight discrepancies between visual and proprioceptive sensory information. These studies contribute valuable insights for designing immersive virtual experiences and interaction techniques suitable for each task. This dissertation presents the design, implementation, and evaluation of a tangible VR Lab where spatiotemporal morphing scenarios can be studied. As a case study, we restricted the scope of the research to three spatial morphing scenarios and one temporal morphing scenario. The spatial morphing scenarios compared Euclidean and hyperbolic geometries, studied size discordance between physical and virtual objects, and the representation of hands in VR. The temporal morphing scenario investigated from what visual delay the task performance is affected. The users’ adaptability to the different spatiotemporal conditions was assessed based on task completion time, questionnaires, and observed behaviours. The results revealed significant differences between Euclidean and hyperbolic spaces. They also showed a preference for handling virtual and physical objects with concordant sizes, without any virtual representation of the hands. Although task performance was affected from 200 ms onwards, participants considered the ease of the task to be affected only from 500 ms visual delay onwards.A Realidade Virtual (RV) permite explorar mudanças no espaço e no tempo que de outra forma seriam difíceis de simular no mundo real. Torna-se possível transformar o mundo virtual aumentando ou diminuindo as distâncias ou manipulando os atrasos no tempo. A análise da adaptabilidade dos utilizadores a diferentes condições espaço-temporais permite estudar a perceção humana e encontrar a combinação certa de paradigmas de interação. Diferentes métodos têm sido propostos na literatura para oferecer aos utilizadores técnicas intuitivas de navegação em espaços virtuais amplos, mesmo que restritos a pequenas áreas físicas de jogo. Outros estudos investigam a tolerância à latência, sugerindo a incapacidade do ser humano de detetar ligeiras discrepâncias entre a informação sensorial visual e propriocetiva. Estes estudos contribuem com valiosas informações para conceber experiências virtuais imersivas e técnicas de interação adequadas a cada tarefa. Esta dissertação apresenta o desenho, implementação e avaliação de um Laboratório de RV tangível onde podem ser estudados cenários de distorção espaço-temporal. Como estudo de caso, restringimos o âmbito da investigação a três cenários de distorção espacial e um cenário de distorção temporal. Os cenários de distorção espacial compararam geometrias Euclidianas e hiperbólicas, estudaram a discordância de tamanho entre objetos físicos e virtuais, e a representação das mãos em RV. O cenário de distorção temporal investigou a partir de que atraso visual o desempenho da tarefa é afetado. A adaptabilidade dos utilizadores às diferentes condições espaço-temporais foi avaliada com base no tempo de conclusão da tarefa, questionários, e comportamentos observados. Os resultados revelaram diferenças significativas entre os espaços Euclidiano e hiperbólico. Também mostraram a preferência pelo manuseamento de objetos virtuais e físicos com tamanhos concordantes, sem qualquer representação virtual das mãos. Embora o desempenho da tarefa tenha sido afetado a partir dos 200 ms, os participantes consideraram que a facilidade da tarefa só foi afetada a partir dos 500 ms de atraso visual

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

Taking the lab on the road and bringing the road to the lab: On using mixed-methods and virtual reality to study a location-based task

In earlier work, a lab and field study were employed to evaluate participants who used a digital map to complete a surveying task. The lab incorporated photos to simulate various scenarios within the task environment. It had a high degree of experimental control, strengths in quantitative data collection, and it could be easily replicated. Whereas the field study took place in the task’s natural setting (a neighborhood); it afforded participants to navigate the environment on foot, which allowed for more ecologically valid task outcomes and rich qualitative data collection. The strengths of the lab method were desired, but the rich context and the ecological validity of the field study proved to be critical to outcomes. In this research, three follow-up experiments were conducted. The first two field experiments explored differences in task outcomes between fieldworkers with high spatial visualization ability and low spatial visualization ability. Participants completed a series of surveying tasks using paper maps while navigating a neighborhood. The results indicated that task performance outcomes and behavior could be linked to participants\u27 spatial visualization ability, their map usage patterns, and environmental factors. In the third experiment, a VR lab was used to replicate a field experiment on the task as it was performed by digital map users. An approach is highlighted to recreate the task environment—a neighborhood that was large in extent—using an immersive virtual environment (IVE). Outcomes from the field are compared to those of the VR lab, which enabled participants to move through the simulated neighborhood using a hands-free interface. Using this approach, strengths of the lab method (i.e., its experimental control) are combined with the ecological validity afforded to natural setting research. The results indicate that real-world behaviors observed in the field—and some of the expected task performance outcomes—were also evident in the VR lab. Many of the findings corroborate those of the two prior field experiments. Comparisons made across experiments show that task outcomes were linked to participants’ spatial visualization ability, their workflows, the street layout of the neighborhood, as well as the type of map used (i.e., paper vs. digital) and the styles of map use. This methodology can be applied—in the field and in lab settings—to evaluate location-based tasks that involve pedestrian navigation and map use; it can also be used to assess and validate VR labs that are designed to replicate mobile HCI field studies by simulating real-world task environments