1,039 research outputs found
Natural Walking in Virtual Reality:A Review
Recent technological developments have finally brought virtual reality (VR) out of the laboratory and into the hands of developers and consumers. However, a number of challenges remain. Virtual travel is one of the most common and universal tasks performed inside virtual environments, yet enabling users to navigate virtual environments is not a trivial challenge—especially if the user is walking. In this article, we initially provide an overview of the numerous virtual travel techniques that have been proposed prior to the commercialization of VR. Then we turn to the mode of travel that is the most difficult to facilitate, that is, walking. The challenge of providing users with natural walking experiences in VR can be divided into two separate, albeit related, challenges: (1) enabling unconstrained walking in virtual worlds that are larger than the tracked physical space and (2) providing users with appropriate multisensory stimuli in response to their interaction with the virtual environment. In regard to the first challenge, we present walking techniques falling into three general categories: repositioning systems, locomotion based on proxy gestures, and redirected walking. With respect to multimodal stimuli, we focus on how to provide three types of information: external sensory information (visual, auditory, and cutaneous), internal sensory information (vestibular and kinesthetic/proprioceptive), and efferent information. Finally, we discuss how the different categories of walking techniques compare and discuss the challenges still facing the research community.</jats:p
Inattentional Blindness for Redirected Walking Using Dynamic Foveated Rendering
Redirected walking is a Virtual Reality(VR) locomotion technique which
enables users to navigate virtual environments (VEs) that are spatially larger
than the available physical tracked space. In this work we present a novel
technique for redirected walking in VR based on the psychological phenomenon of
inattentional blindness. Based on the user's visual fixation points we divide
the user's view into zones. Spatially-varying rotations are applied according
to the zone's importance and are rendered using foveated rendering. Our
technique is real-time and applicable to small and large physical spaces.
Furthermore, the proposed technique does not require the use of stimulated
saccades but rather takes advantage of naturally occurring saccades and blinks
for a complete refresh of the framebuffer. We performed extensive testing and
present the analysis of the results of three user studies conducted for the
evaluation
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
Walking with virtual humans : understanding human response to virtual humanoids' appearance and behaviour while navigating in immersive VR
In this thesis, we present a set of studies whose results have allowed us to analyze how to improve the realism, navigation, and behaviour of the avatars in an immersive virtual reality environment. In our simulations, participants must perform a series of tasks and we have analyzed perceptual and behavioural data. The results of the studies have allowed us to deduce what improvements are needed to be incorporated to the original simulations, in order to enhance the perception of realism, the navigation technique, the rendering of the avatars, their behaviour or their animations.
The most reliable technique for simulating avatars’ behaviour in a virtual reality environment should be based on the study of how humans behave within the environment. For this purpose, it is necessary to build virtual environments where participants can navigate safely and comfortably with a proper metaphor and, if the environment is populated with avatars, simulate their behaviour accurately. All these aspects together will make the participants behave in a way that is closer to how they would behave in the real world. Besides, the integration of these concepts could provide an ideal platform to develop different types of applications with and without collaborative virtual reality such as emergency simulations, teaching, architecture, or designing.
In the first contribution of this thesis, we carried out an experiment to study human decision making during an evacuation. We were interested to evaluate to what extent the behaviour of a virtual crowd can affect individuals' decisions. From the second contribution, in which we studied the perception of realism with bots and humans performing just locomotion or varied animations, we can conclude that the combination of having human-like avatars with animation variety can increase the overall realism of a crowd simulation, trajectories and animation. The preliminary study presented in the third contribution of this thesis showed that realistic rendering of the environment and the avatars do not appear to increase the perception of realism in the participants, which is consistent with works presented previously.
The preliminary results in our walk-in-place contribution showed a seamless and natural transition between walk-in-place and normal walk. Our system provided a velocity mapping function that closely resembles natural walk. We observed through a pilot study that the system successfully reduces motion sickness and enhances immersion. Finally, the results of the contribution related to locomotion in collaborative virtual reality showed that animation synchronism and footstep sound of the avatars representing the participants do not seem to have a strong impact in terms of presence and feeling of avatar control. However, in our experiment, incorporating natural animations and footstep sound resulted in smaller clearance values in VR than previous work in the literature.
The main objective of this thesis was to improve different factors related to virtual reality experiences to make the participants feel more comfortable in the virtual environment. These factors include the behaviour and appearance of the virtual avatars and the navigation through the simulated space in the experience. By increasing the realism of the avatars and facilitating navigation, high scores in presence are achieved during the simulations. This provides an ideal framework for developing collaborative virtual reality applications or emergency simulations that require participants to feel as if they were in real life.En aquesta tesi, es presenta un conjunt d'estudis els resultats dels quals ens han permès analitzar com millorar el realisme, la navegació i el comportament dels avatars en un entorn de realitat virtual immersiu. En les nostres simulacions, els participants han de realitzar una sèrie de tasques i hem analitzat dades perceptives i de comportament mentre les feien. Els resultats dels estudis ens han permès deduir quines millores són necessàries per a ser incorporades a les simulacions originals, amb la finalitat de millorar la percepció del realisme, la tècnica de navegació, la representació dels avatars, el seu comportament o les seves animacions. La tècnica més fiable per simular el comportament dels avatars en un entorn de realitat virtual hauria de basar-se en l'estudi de com es comporten els humans dins de l¿entorn virtual. Per a aquest propòsit, és necessari construir entorns virtuals on els participants poden navegar amb seguretat i comoditat amb una metàfora adequada i, si l¿entorn està poblat amb avatars, simular el seu comportament amb precisió. Tots aquests aspectes junts fan que els participants es comportin d'una manera més pròxima a com es comportarien en el món real. A més, la integració d'aquests conceptes podria proporcionar una plataforma ideal per desenvolupar diferents tipus d'aplicacions amb i sense realitat virtual col·laborativa com simulacions d'emergència, ensenyament, arquitectura o disseny. En la primera contribució d'aquesta tesi, vam realitzar un experiment per estudiar la presa de decisions durant una evacuació. Estàvem interessats a avaluar en quina mesura el comportament d'una multitud virtual pot afectar les decisions dels participants. A partir de la segona contribució, en la qual estudiem la percepció del realisme amb robots i humans que realitzen només una animació de caminar o bé realitzen diverses animacions, vam arribar a la conclusió que la combinació de tenir avatars semblants als humans amb animacions variades pot augmentar la percepció del realisme general de la simulació de la multitud, les seves trajectòries i animacions. L'estudi preliminar presentat en la tercera contribució d'aquesta tesi va demostrar que la representació realista de l¿entorn i dels avatars no semblen augmentar la percepció del realisme en els participants, que és coherent amb treballs presentats anteriorment. Els resultats preliminars de la nostra contribució de walk-in-place van mostrar una transició suau i natural entre les metàfores de walk-in-place i caminar normal. El nostre sistema va proporcionar una funció de mapatge de velocitat que s'assembla molt al caminar natural. Hem observat a través d'un estudi pilot que el sistema redueix amb èxit el motion sickness i millora la immersió. Finalment, els resultats de la contribució relacionada amb locomoció en realitat virtual col·laborativa van mostrar que el sincronisme de l'animació i el so dels avatars que representen els participants no semblen tenir un fort impacte en termes de presència i sensació de control de l'avatar. No obstant això, en el nostre experiment, la incorporació d'animacions naturals i el so de passos va donar lloc a valors de clearance més petits en RV que treballs anteriors ja publicats. L'objectiu principal d'aquesta tesi ha estat millorar els diferents factors relacionats amb experiències de realitat virtual immersiva per fer que els participants se sentin més còmodes en l'entorn virtual. Aquests factors inclouen el comportament i l'aparença dels avatars i la navegació a través de l'entorn virtual. En augmentar el realisme dels avatars i facilitar la navegació, s'aconsegueixen altes puntuacions en presència durant les simulacions. Això proporciona un marc ideal per desenvolupar aplicacions col·laboratives de realitat virtual o simulacions d'emergència que requereixen que els participants se sentin com si estiguessin en la vida realPostprint (published version
Inattentional Blindness for Redirected Walking Using Dynamic Foveated Rendering
Redirected walking is a Virtual Reality(VR) locomotion technique which enables users to navigate virtual environments (VEs) that are spatially larger than the available physical tracked space. In this work we present a novel technique for redirected walking in VR based on the psychological phenomenon of inattentional blindness. Based on the user's visual fixation points we divide the user's view into zones. Spatially-varying rotations are applied according to the zone's importance and are rendered using foveated rendering. Our technique is real-time and applicable to small and large physical spaces. Furthermore, the proposed technique does not require the use of stimulated saccades but rather takes advantage of naturally occurring saccades and blinks for a complete refresh of the framebuffer. We performed extensive testing and present the analysis of the results of three user studies conducted for the evaluation
VR-assisted architectural design in a heritage site: the Sagrada Família case study
Virtual Reality (VR) simulations have long been proposed to allow users to explore both yet-to-built buildings in architectural design, and ancient, remote or disappeared buildings in cultural heritage. In this paper we describe an on-going VR project on an UNESCO World Heritage Site that simultaneously addresses both scenarios: supporting architects in the task of designing the remaining parts of a large unfinished building, and simulating existing parts that define the environment that new designs must conform to. The main challenge for the team of architects is to advance towards the project completion being faithful to the original Gaudí’s project, since many plans, drawings and plaster models were lost. We analyze the main requirements for collaborative architectural design in such a unique scenario, describe the main technical challenges, and discuss the lessons learned after one year of use of the system.Peer ReviewedPostprint (published version
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
Enhanced Virtuality: Increasing the Usability and Productivity of Virtual Environments
Mit stetig steigender Bildschirmauflösung, genauerem Tracking und fallenden Preisen stehen Virtual Reality (VR) Systeme kurz davor sich erfolgreich am Markt zu etablieren. Verschiedene Werkzeuge helfen Entwicklern bei der Erstellung komplexer Interaktionen mit mehreren Benutzern innerhalb adaptiver virtueller Umgebungen. Allerdings entstehen mit der Verbreitung der VR-Systeme auch zusätzliche Herausforderungen: Diverse Eingabegeräte mit ungewohnten Formen und Tastenlayouts verhindern eine intuitive Interaktion. Darüber hinaus zwingt der eingeschränkte Funktionsumfang bestehender Software die Nutzer dazu, auf herkömmliche PC- oder Touch-basierte Systeme zurückzugreifen. Außerdem birgt die Zusammenarbeit mit anderen Anwendern am gleichen Standort Herausforderungen hinsichtlich der Kalibrierung unterschiedlicher Trackingsysteme und der Kollisionsvermeidung. Beim entfernten Zusammenarbeiten wird die Interaktion durch Latenzzeiten und Verbindungsverluste zusätzlich beeinflusst. Schließlich haben die Benutzer unterschiedliche Anforderungen an die Visualisierung von Inhalten, z.B. Größe, Ausrichtung, Farbe oder Kontrast, innerhalb der virtuellen Welten. Eine strikte Nachbildung von realen Umgebungen in VR verschenkt Potential und wird es nicht ermöglichen, die individuellen Bedürfnisse der Benutzer zu berücksichtigen.
Um diese Probleme anzugehen, werden in der vorliegenden Arbeit Lösungen in den Bereichen Eingabe, Zusammenarbeit und Erweiterung von virtuellen Welten und Benutzern vorgestellt, die darauf abzielen, die Benutzerfreundlichkeit und Produktivität von VR zu erhöhen. Zunächst werden PC-basierte Hardware und Software in die virtuelle Welt übertragen, um die Vertrautheit und den Funktionsumfang bestehender Anwendungen in VR zu erhalten. Virtuelle Stellvertreter von physischen Geräten, z.B. Tastatur und Tablet, und ein VR-Modus für Anwendungen ermöglichen es dem Benutzer reale Fähigkeiten in die virtuelle Welt zu übertragen. Des Weiteren wird ein Algorithmus vorgestellt, der die Kalibrierung mehrerer ko-lokaler VR-Geräte mit hoher Genauigkeit und geringen Hardwareanforderungen und geringem Aufwand ermöglicht. Da VR-Headsets die reale Umgebung der Benutzer ausblenden, wird die Relevanz einer Ganzkörper-Avatar-Visualisierung für die Kollisionsvermeidung und das entfernte Zusammenarbeiten nachgewiesen. Darüber hinaus werden personalisierte räumliche oder zeitliche Modifikationen vorgestellt, die es erlauben, die Benutzerfreundlichkeit, Arbeitsleistung und soziale Präsenz von Benutzern zu erhöhen. Diskrepanzen zwischen den virtuellen Welten, die durch persönliche Anpassungen entstehen, werden durch Methoden der Avatar-Umlenkung (engl. redirection) kompensiert. Abschließend werden einige der Methoden und Erkenntnisse in eine beispielhafte Anwendung integriert, um deren praktische Anwendbarkeit zu verdeutlichen.
Die vorliegende Arbeit zeigt, dass virtuelle Umgebungen auf realen Fähigkeiten und Erfahrungen aufbauen können, um eine vertraute und einfache Interaktion und Zusammenarbeit von Benutzern zu gewährleisten. Darüber hinaus ermöglichen individuelle Erweiterungen des virtuellen Inhalts und der Avatare Einschränkungen der realen Welt zu überwinden und das Erlebnis von VR-Umgebungen zu steigern
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