Improving spatial orientation in virtual reality with leaning-based interfaces

Advancement in technology has made Virtual Reality (VR) increasingly portable, affordable and accessible to a broad audience. However, large scale VR locomotion still faces major challenges in the form of spatial disorientation and motion sickness. While spatial updating is automatic and even obligatory in real world walking, using VR controllers to travel can cause disorientation. This dissertation presents two experiments that explore ways of improving spatial updating and spatial orientation in VR locomotion while minimizing cybersickness. In the first study, we compared a hand-held controller with HeadJoystick, a leaning-based interface, in a 3D navigational search task. The results showed that leaning-based interface helped participant spatially update more effectively than when using the controller. In the second study, we designed a "HyperJump" locomotion paradigm which allows to travel faster while limiting its optical flow. Not having any optical flow (as in traditional teleport paradigms) has been shown to help reduce cybersickness, but can also cause disorientation. By interlacing continuous locomotion with teleportation we showed that user can travel faster without compromising spatial updating

Lean to Fly: Leaning-Based Embodied Flying can Improve Performance and User Experience in 3D Navigation

When users in virtual reality cannot physically walk and self-motions are instead only visually simulated, spatial updating is often impaired. In this paper, we report on a study that investigated if HeadJoystick, an embodied leaning-based flying interface, could improve performance in a 3D navigational search task that relies on maintaining situational awareness and spatial updating in VR. We compared it to Gamepad, a standard flying interface. For both interfaces, participants were seated on a swivel chair and controlled simulated rotations by physically rotating. They either leaned (forward/backward, right/left, up/down) or used the Gamepad thumbsticks for simulated translation. In a gamified 3D navigational search task, participants had to find eight balls within 5 min. Those balls were hidden amongst 16 randomly positioned boxes in a dark environment devoid of any landmarks. Compared to the Gamepad, participants collected more balls using the HeadJoystick. It also minimized the distance travelled, motion sickness, and mental task demand. Moreover, the HeadJoystick was rated better in terms of ease of use, controllability, learnability, overall usability, and self-motion perception. However, participants rated HeadJoystick could be more physically fatiguing after a long use. Overall, participants felt more engaged with HeadJoystick, enjoyed it more, and preferred it. Together, this provides evidence that leaning-based interfaces like HeadJoystick can provide an affordable and effective alternative for flying in VR and potentially telepresence drones

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

Development and evaluation of an interactive virtual audience for a public speaking training application

Einleitung: Eine der häufigsten sozialen Ängste ist die Angst vor öffentlichem Sprechen. Virtual-Reality- (VR-) Trainingsanwendungen sind ein vielversprechendes Instrument, um die Sprechangst zu reduzieren und die individuellen Sprachfähigkeiten zu verbessern. Grundvoraussetzung hierfür ist die Implementierung eines realistischen und interaktiven Sprecher-Publikum-Verhaltens. Ziel: Die Studie zielte darauf ab, ein realistisches und interaktives Publikum für eine VR-Anwendung zu entwickeln und zu bewerten, welches für die Trainingsanwendung von öffentlichem Sprechen angewendet wird. Zunächst wurde eine Beobachtungsstudie zu den Verhaltensmustern von Sprecher und Publikum durchgeführt. Anschließend wurden die identifizierten Muster in eine VR-Anwendung implementiert. Die Wahrnehmung der implementierten Interaktionsmuster wurde in einer weiteren Studie aus Sicht der Nutzer evaluiert. Beobachtungsstudie (1): Aufgrund der nicht ausreichenden Datengrundlage zum realen interaktiven Verhalten zwischen Sprecher und Publikum lautet die erste Forschungsfrage "Welche Sprecher-Publikums-Interaktionsmuster können im realen Umfeld identifiziert werden?". Es wurde eine strukturierte, nicht teilnehmende, offene Beobachtungsstudie durchgeführt. Ein reales Publikum wurde auf Video aufgezeichnet und die Inhalte analysiert. Die Stichprobe ergab N = 6484 beobachtete Interaktionsmuster. Es wurde festgestellt, dass Sprecher mehr Dialoge als das Publikum initiieren und wie die Zuschauer auf Gesichtsausdrücke und Gesten der Sprecher reagieren. Implementierungsstudie (2): Um effiziente Wege zur Implementierung der Ergebnisse der Beobachtungsstudie in die Trainingsanwendung zu finden, wurde die Forschungsfrage wie folgt formuliert: "Wie können Interaktionsmuster zwischen Sprecher und Publikum in eine virtuelle Anwendung implementiert werden?". Das Hardware-Setup bestand aus einer CAVE, Infitec-Brille und einem ART Head-Tracking. Die Software wurde mit 3D-Excite RTT DeltaGen 12.2 realisiert. Zur Beantwortung der zweiten Forschungsfrage wurden mehrere mögliche technische Lösungen systematisch untersucht, bis effiziente Lösungen gefunden wurden. Infolgedessen wurden die selbst erstellte Audioerkennung, die Kinect-Bewegungserkennung, die Affectiva-Gesichtserkennung und die selbst erstellten Fragen implementiert, um das interaktive Verhalten des Publikums in der Trainingsanwendung für öffentliches Sprechen zu realisieren. Evaluationsstudie (3): Um herauszufinden, ob die Implementierung interaktiver Verhaltensmuster den Erwartungen der Benutzer entsprach, wurde die dritte Forschungsfrage folgendermaßen formuliert: “Wie beeinflusst die Interaktivität einer virtuellen Anwendung für öffentliches Reden die Benutzererfahrung?”. Eine experimentelle Benutzer-Querschnittsstudie wurde mit N = 57 Teilnehmerinnen (65% Männer, 35% Frauen; Durchschnittsalter = 25.98, SD = 4.68) durchgeführt, die entweder der interaktiven oder nicht-interaktiven VR-Anwendung zugewiesen wurden. Die Ergebnisse zeigten, dass, es einen signifikanten Unterschied in der Wahrnehmung zwischen den beiden Anwendungen gab. Allgemeine Schlussfolgerungen: Interaktionsmuster zwischen Sprecher und Publikum, die im wirklichen Leben beobachtet werden können, wurden in eine VR-Anwendung integriert, die Menschen dabei hilft, Angst vor dem öffentlichen Sprechen zu überwinden und ihre öffentlichen Sprechfähigkeiten zu trainieren. Die Ergebnisse zeigten eine hohe Relevanz der VR-Anwendungen für die Simulation öffentlichen Sprechens. Obwohl die Fragen des Publikums manuell gesteuert wurden, konnte das neu gestaltete Publikum mit den Versuchspersonen interagieren. Die vorgestellte VR-Anwendung zeigt daher einen hohen potenziellen Nutzen, Menschen beim Trainieren von Sprechfähigkeiten zu unterstützen. Die Fragen des Publikums wurden immer noch manuell von einem Bediener reguliert und die Studie wurde mit Teilnehmern durchgeführt, die nicht unter einem hohen Grad an Angst vor öffentlichem Sprechen leiden. Bei zukünftigen Studien sollten fortschrittlichere Technologien eingesetzt werden, beispielsweise Spracherkennung, 3D-Aufzeichnungen oder 3D-Livestreams einer realen Person und auch Teilnehmer mit einem hohen Grad an Angst vor öffentlichen Ansprachen beziehungsweise Sprechen in der Öffentlichkeit.Introduction: Fear of public speaking is the most common social fear. Virtual reality (VR) training applications are a promising tool to improve public speaking skills. To be successful, applications should feature a high scenario fidelity. One way to improve it is to implement realistic speaker-audience interactive behavior. Objective: The study aimed to develop and evaluate a realistic and interactive audience for a VR public speaking training application. First, an observation study on real speaker-audience interactive behavior patterns was conducted. Second, identified patterns were implemented in the VR application. Finally, an evaluation study identified users’ perceptions of the training application. Observation Study (1): Because of the lack of data on real speaker-audience interactive behavior, the first research question to be answered was “What speaker-audience interaction patterns can be identified in real life?”. A structured, non-participant, overt observation study was conducted. A real audience was video recorded, and content analyzed. The sample resulted in N = 6,484 observed interaction patterns. It was found that speakers, more often than audience members, initiate dialogues and how audience members react to speakers’ facial expressions and gestures. Implementation Study (2): To find efficient ways of implementing the results of the observation study in the training application, the second research question was formulated as: “How can speaker-audience interaction patterns be implemented into the virtual public speaking application?”. The hardware setup comprised a CAVE, Infitec glasses, and ART head tracking. The software was realized with 3D-Excite RTT DeltaGen 12.2. To answer the second research question, several possible technical solutions were explored systematically, until efficient solutions were found. As a result, self-created audio recognition, Kinect motion recognition, Affectiva facial recognition, and manual question generation were implemented to provide interactive audience behavior in the public speaking training application. Evaluation Study (3): To find out if implementing interactive behavior patterns met users’ expectations, the third research question was formulated as “How does interactivity of a virtual public speaking application affect user experience?”. An experimental, cross-sectional user study was conducted with (N = 57) participants (65% men, 35% women; Mage = 25.98, SD = 4.68) who used either an interactive or a non-interactive VR application condition. Results revealed that there was a significant difference in users’ perception of the two conditions. General Conclusions: Speaker-audience interaction patterns that can be observed in real life were incorporated into a VR application that helps people to overcome the fear of public speaking and train their public speaking skills. The findings showed a high relevance of interactivity for VR public speaking applications. Although questions from the audience were still regulated manually, the newly designed audience could interact with the speakers. Thus, the presented VR application is of potential value in helping people to train their public speaking skills. The questions from the audience were still regulated manually by an operator and we conducted the study with participants not suffering from high degrees of public speaking fear. Future work may use more advanced technology, such as speech recognition, 3D-records, or live 3D-streams of an actual person and include participants with high degrees of public speaking fear

Tailoring Interaction. Sensing Social Signals with Textiles.

Nonverbal behaviour is an important part of conversation and can reveal much about the nature of an interaction. It includes phenomena ranging from large-scale posture shifts to small scale nods. Capturing these often spontaneous phenomena requires unobtrusive sensing techniques that do not interfere with the interaction. We propose an underexploited sensing modality for sensing nonverbal behaviours: textiles. As a material in close contact with the body, they provide ubiquitous, large surfaces that make them a suitable soft interface. Although the literature on nonverbal communication focuses on upper body movements such as gestures, observations of multi-party, seated conversations suggest that sitting postures, leg and foot movements are also systematically related to patterns of social interaction. This thesis addressees the following questions: Can the textiles surrounding us measure social engagement? Can they tell who is speaking, and who, if anyone, is listening? Furthermore, how should wearable textile sensing systems be designed and what behavioural signals could textiles reveal? To address these questions, we have designed and manufactured bespoke chairs and trousers with integrated textile pressure sensors, that are introduced here. The designs are evaluated in three user studies that produce multi-modal datasets for the exploration of fine-grained interactional signals. Two approaches to using these bespoke textile sensors are explored. First, hand crafted sensor patches in chair covers serve to distinguish speakers and listeners. Second, a pressure sensitive matrix in custom-made smart trousers is developed to detect static sitting postures, dynamic bodily movement, as well as basic conversational states. Statistical analyses, machine learning approaches, and ethnographic methods show that by moni- toring patterns of pressure change alone it is possible to not only classify postures with high accuracy, but also to identify a wide range of behaviours reliably in individuals and groups. These findings es- tablish textiles as a novel, wearable sensing system for applications in social sciences, and contribute towards a better understanding of nonverbal communication, especially the significance of posture shifts when seated. If chairs know who is speaking, if our trousers can capture our social engagement, what role can smart textiles have in the future of human interaction? How can we build new ways to map social ecologies and tailor interactions

Freehand-Steering Locomotion Techniques for Immersive Virtual Environments: A Comparative Evaluation

Virtual reality has achieved significant popularity in recent years, and allowing users to move freely within an immersive virtual world has become an important factor critical to realize. The user’s interactions are generally designed to increase the perceived realism, but the locomotion techniques and how these affect the user’s task performance still represent an open issue, much discussed in the literature. In this article, we evaluate the efficiency and effectiveness of, and user preferences relating to, freehand locomotion techniques designed for an immersive virtual environment performed through hand gestures tracked by a sensor placed in the egocentric position and experienced through a head-mounted display. Three freehand locomotion techniques have been implemented and compared with each other, and with a baseline technique based on a controller, through qualitative and quantitative measures. An extensive user study conducted with 60 subjects shows that the proposed methods have a performance comparable to the use of the controller, further revealing the users’ preference for decoupling the locomotion in sub-tasks, even if this means renouncing precision and adapting the interaction to the possibilities of the tracker sensor

Investigation of an emotional virtual human modelling method

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.In order to simulate virtual humans more realistically and enable them life-like behaviours, several exploration research on emotion calculation, synthetic perception, and decision making process have been discussed. A series of sub-modules have been designed and simulation results have been presented with discussion. A visual based synthetic perception system has been proposed in this thesis, which allows virtual humans to detect the surrounding virtual environment through a collision-based synthetic vision system. It enables autonomous virtual humans to change their emotion states according to stimuli in real time. The synthetic perception system also allows virtual humans to remember limited information within their own First-in-first-out short-term virtual memory. The new emotion generation method includes a novel hierarchical emotion structure and a group of emotion calculation equations, which enables virtual humans to perform emotionally in real-time according to their internal and external factors. Emotion calculation equations used in this research were derived from psychologic emotion measurements. Virtual humans can utilise the information in virtual memory and emotion calculation equations to generate their own numerical emotion states within the hierarchical emotion structure. Those emotion states are important internal references for virtual humans to adopt appropriate behaviours and also key cues for their decision making. The work introduces a dynamic emotional motion database structure for virtual human modelling. When developing realistic virtual human behaviours, lots of subjects were motion-captured whilst performing emotional motions with or without intent. The captured motions were endowed to virtual characters and implemented in different virtual scenarios to help evoke and verify design ideas, possible consequences of simulation (such as fire evacuation). This work also introduced simple heuristics theory into decision making process in order to make the virtual human’s decision making more like real human. Emotion values are proposed as a group of the key cues for decision making under the simple heuristic structures. A data interface which connects the emotion calculation and the decision making structure together has also been designed for the simulation system

Towards Naturalistic Interfaces of Virtual Reality Systems

Interaction plays a key role in achieving realistic experience in virtual reality (VR). Its realization depends on interpreting the intents of human motions to give inputs to VR systems. Thus, understanding human motion from the computational perspective is essential to the design of naturalistic interfaces for VR. This dissertation studied three types of human motions, including locomotion (walking), head motion and hand motion in the context of VR. For locomotion, the dissertation presented a machine learning approach for developing a mechanical repositioning technique based on a 1-D treadmill for interacting with a unique new large-scale projective display, called the Wide-Field Immersive Stereoscopic Environment (WISE). The usability of the proposed approach was assessed through a novel user study that asked participants to pursue a rolling ball at variable speed in a virtual scene. In addition, the dissertation studied the role of stereopsis in avoiding virtual obstacles while walking by asking participants to step over obstacles and gaps under both stereoscopic and non-stereoscopic viewing conditions in VR experiments. In terms of head motion, the dissertation presented a head gesture interface for interaction in VR that recognizes real-time head gestures on head-mounted displays (HMDs) using Cascaded Hidden Markov Models. Two experiments were conducted to evaluate the proposed approach. The first assessed its offline classification performance while the second estimated the latency of the algorithm to recognize head gestures. The dissertation also conducted a user study that investigated the effects of visual and control latency on teleoperation of a quadcopter using head motion tracked by a head-mounted display. As part of the study, a method for objectively estimating the end-to-end latency in HMDs was presented. For hand motion, the dissertation presented an approach that recognizes dynamic hand gestures to implement a hand gesture interface for VR based on a static head gesture recognition algorithm. The proposed algorithm was evaluated offline in terms of its classification performance. A user study was conducted to compare the performance and the usability of the head gesture interface, the hand gesture interface and a conventional gamepad interface for answering Yes/No questions in VR. Overall, the dissertation has two main contributions towards the improvement of naturalism of interaction in VR systems. Firstly, the interaction techniques presented in the dissertation can be directly integrated into existing VR systems offering more choices for interaction to end users of VR technology. Secondly, the results of the user studies of the presented VR interfaces in the dissertation also serve as guidelines to VR researchers and engineers for designing future VR systems