This thesis tells the story of a design case creating an user interface for a MMORPG where the player are able control the body language of the avatar. By this the game can achieve a gameplay about drama and strong characterization. The thesis addresses considerations on what aspects of body language that can be important for computer games and other virtual environments. It also offers design considerations when designing interfaces for using gestures and other body signals to communicate emotions in virtual environments such as computer games. The main design consideration when creating the interface was to treat the player as an actor and the game world as a stage. The player needs to be in control of combinations of facial expressions, body posture and gestures as well as relative avatar positioning to other characters and objects. The interface was first tested as a paper prototype, re-designed, re-tested and then implemented into a computer prototype.

Les modèles de simulation de foules visent généralement à produire des foules visuellement crédibles avec l'intention d'insuffler de la vie à des environnements virtuels. Notre travail se concentre sur la génération de comportements statistiquement cohérents qui peuvent être utilisés pour piloter des modèles de simulation de foules sur de longues périodes de temps, jusqu'à plusieurs jours. Dans les foules réelles, les comportements des individus dépendent principalement de l'activité qu'ils ont l'intention d'effectuer. La façon d’ordonnancer cette activité repose sur l'interaction étroite qui existe entre l'environnement, les contraintes spatiales et temporelles associées à l'activité et les caractéristiques personnelles des individus. Par rapport à l'état de l'art, notre modèle gérer mieux cette interaction. Nos principales contributions se situent dans le domaine de l'ordonnancement d'activités et de la planification de chemin. Dans un premier temps, nous proposons un processus d'ordonnancement d'activités individuelles et son extension aux activités coopératives. Basé sur les descriptions de l'environnement, des activités désirées et des caractéristiques des agents, ces processus génèrent une séquence de la tâche pour chaque agent. Des lieux où ces tâches doivent être effectuées sont sélectionnés et un timing relâché est produit. Cet ordonnancement est compatible avec les contraintes spatiales et temporelles liées à l'environnement et à l'activité prévue par l'agent et par d'autres agents en coopération. Il prend également en compte les caractéristiques personnelles des agents, induisant de la diversité dans les ordonnancements produits. Nous montrons que notre modèle produit des comportements statistiquement cohérents avec ceux produits par des personnes dans les mêmes situations. Dans un second temps, nous proposons un processus de planification de chemins hiérarchique. Il repose sur un processus d'analyse de l'environnement automatique qui produit une représentation hiérarchique sémantiquement cohérente des villes virtuelles. La nature hiérarchique de cette représentation est utilisée pour modéliser différents niveaux de prise de décisions. Un chemin grossier est d'abord calculé, puis raffiné pendant la navigation lorsque de l'information pertinente est disponible, permettant ainsi à l'agent d'adapter son chemin à des événements inattendus. Le modèle proposé gère des décisions rationnelles à long terme guidant la navigation des agents dans les villes virtuelles. Il prend en compte la forte relation entre le temps, l'espace et l'activité pour produire les comportements des agents plus crédibles de. Il peut être utilisé pour peupler facilement des villes virtuelles avec des foules au sein desquelles des phénomènes observables émergent de l'activité individuelle. / Crowd simulation models usually aim at producing visually credible crowds with the intent of giving life to virtual environments. Our work focusses on generating statistically consistent behaviours that can be used to pilot crowd simulation models over long periods of time, up to multiple days. In real crowds, people's behaviours mainly depend on the activities they intend to perform. The way this activity is scheduled rely on the close interaction between the environment, space and time constraints associated with the activity and personal characteristics of individuals. Compared to the state of the art, our model better handle this interaction. Our main contributions lie in the domain of activity scheduling and path planning. First, we propose an individual activity scheduling process and its extension to cooperative activity scheduling. Based on descriptions of the environment, of intended activities and of agents' characteristics, these processes generate a task schedule for each agent. Locations where the tasks should be performed are selected and a relaxed agenda is produced. This task schedule is compatible with spatial and temporal constraints associated with the environment and with the intended activity of the agent and of other cooperating agents. It also takes into account the agents personal characteristics, inducing diversity in produced schedules. We show that our model produces schedules statistically coherent with the ones produced by humans in the same situations. Second, we propose a hierarchical path-planning process. It relies on an automatic environment analysis process that produces a semantically coherent hierarchical representation of virtual cities. The hierarchical nature of this representation is used to model different levels of decision making related to path planning. A coarse path is first computed, then refined during navigation when relevant information is available. It enable the agent to seamlessly adapt its path to unexpected events. The proposed model handles long term rational decisions driving the navigation of agents in virtual cities. It considers the strong relationship between time, space and activity to produce more credible agents' behaviours. It can be used to easily populate virtual cities in which observable crowd phenomena emerge from individual activities.

Les développements récents de la réalité virtuelle font du travail collaboratif assisté par ordinateur un outil prometteur et flexible. Il est en effet aujourd’hui possible, de représenter les données ainsi que les utilisateurs eux-mêmes de manière vivante dans les environnements virtuels collaboratifs (EVC). Les EVC se définissent comme des mondes virtuels distribués, générés par ordinateur, dans lesquels les utilisateurs peuvent se rencontrer, communiquer et interagir entre eux, mais aussi avec des données et des objets 3D. Les utilisateurs peuvent être éloignés physiquement, parler des langues différentes et utiliser des systèmes informatiques hétérogènes tout en collaborant malgré tout au sein d’un EVC. L’objectif principal des EVC est de proposer une collaboration fluide entre plusieurs utilisateurs. Ceci implique de prendre en charge un nombre considérable d’échanges, de communications et de négociations mais également de permettre des activités collaboratives. Par ailleurs, il est nécessaire de proposer des techniques d’interaction ainsi que des moyens pour bien prendre conscience de tout ce qui se passe dans l’environnement. Afin de préserver ces différents aspects dans la conception des EVC, nous nous intéressons à quatre facteurs essentiels : l’immersion, la conscience, la communication et l’intuitivité. Ces facteurs sont déterminants pour le succès des systèmes virtuels collaboratifs. En tenant compte des quatre facteurs cités cidessus, nous proposons et évaluons de nouvelles métaphores pour la navigation et la manipulation afin d’améliorer et d’enrichir les techniques d’interactions dans les EVC. Premièrement, nous proposons et évaluons un ensemble de trois métaphores de navigation pour explorer un environnement à plusieurs : indiquer un chemin en dessinant des flèches, illuminer un chemin à suivre et orienter une boussole pour montrer une direction. Ces métaphores peuvent être implémentées dynamiquement et utilisées directement dans n’importe quels environnements. Nos résultats révèlent que ces métaphores de navigation réduisent considérablement le temps passé à chercher un chemin dans des contextes d’exploration collaborative. Par ailleurs, nous avons développé une technique de manipulation directe dédiée aux environnements virtuels immersifs. Cette technique, qui utilise sept points de contrôle, affranchit l’utilisateur de plusieurs difficultés souvent rencontrées telles que le tremblement de la main ou l’effet Heisenberg lors de la manipulation d’objets 3D dans un système de projection immersive. En réduisant le nombre de degrés de liberté de l’objet manipulé à l’aide de point de contrôle, notre technique permet à l’utilisateur de contrôler partiellement l’objet, rendant ainsi la manipulation d’objets volumineux plus aisée. Enfin, nous avons implémenté et évalué deux métaphores d'interaction dans une application de conception et d'aménagement de poste de travail industriel. En tenant compte des quatre facteurs cités ci-dessus, nous avons implémenté une application de conception de poste de travail pour trois principaux types d'utilisateurs : un utilisateur final, un ingénieur et un expert en ergonomie. Afin d'avoir un niveau d'immersion optimal et des interactions naturelles entre des utilisateurs, nous avons implémenté une configuration de système asymétrique pour chaque utilisateur. Chacun pouvait utiliser quelque métaphores de communication implicites qui étaient simples, naturelles, et pertinentes dans notre contexte collaborative. / Recent progress of the virtual reality technology gives the computer supported collaborative work a potential and flexible tool of vividly representing data as well as users themselves in collaborative virtual environments. Collaborative virtual environments have been defined as computer-based, distributed virtual worlds in which people can meet, communicate and interact with others, with data and 3D objects. People may be geometrically far from each other, speak different languages and use heterogeneous computer systems. The ultimate goal in developing collaborative virtual environments is to support a smooth collaboration between multiple users which involves considerable communication and negotiation, cooperative and collaborative activities, interaction techniques, and awareness process. Considering these aspects into the design of a collaborative virtual environment, we are interested in four main factors, including immersion, awareness, communication and naturalness. These factors greatly determine the success of a collaborative virtual system. From the need of improving and completing interaction techniques in CVEs considering the four preceding factors, in this research we propose and evaluate new metaphors for 3D navigation and manipulation techniques. The first contribution of this research is to propose and evaluate a set of three navigation metaphors in a collaborative exploration context, including drawing directional arrows, lighting up path to follow, and orientating a compass to show a direction. These navigation metaphors can be dynamically implemented and used without constraints in any 3D virtual environments. The empirical result of our experiment revealed that these navigation metaphors considerably reduced wasted time in a wayfinding task of a collaborative exploring scenario. We have developed, in the second part of this research, a direct manipulation technique in immersive virtual environments. This manipulation technique deals with some difficulties the user often encounters such as hand jitter or Heisenberg effects while manipulating 3D objects in immersive projection systems. By dividing the number of degrees of freedom of the manipulated object into each handle of our tool, our technique enables a user to partially control the object, making the manipulation of large objects easier in immersive virtual environments. The last contribution of this research is the implementation and evaluation of two interaction metaphors in a digital mock-up application. Taking into account the four factors including immersion, awareness, communication and naturalness, we have built a workstation design application for three main users: an end-user, a design engineer and an ergonomics expert. In order to have an optimal immersion for the whole application and natural interaction between them, we have implemented an asymmetric system setup at each user's site. Each user could use some implicit communication metaphors which were simple, natural and still relevant in our collaborative context.

Distributed virtual environments (DVEs) have been an active area of research and engineering for more than 20 years. The most widely deployed DVEs are network games such as Quake, Halo, and World of Warcraft (WoW), with millions of users and billions of dollars in annual revenue. Deployed DVEs remain expensive centralized implementations despite significant research outlining ways to distribute DVE workloads. This dissertation shows previous DVE research evaluations are inconsistent with deployed DVE needs. Assumptions about avatar movement and proximity - fundamental scale factors - do not match WoW's workload, and likely the workload of other deployed DVEs. Alternate workload models are explored and preliminary conclusions presented. Using realistic workloads it is shown that a fully decentralized DVE cannot be deployed to today's consumers, regardless of its overhead. Residential broadband speeds are improving, and this limitation will eventually disappear. When it does, appropriate security mechanisms will be a fundamental requirement for technology adoption. A trusted auditing system ('Carbon') is presented which has good security, scalability, and resource characteristics for decentralized DVEs. When performing exhaustive auditing, Carbon adds 27% network overhead to a decentralized DVE with a WoW-like workload. This resource consumption can be reduced significantly, depending upon the DVE's risk tolerance. Finally, the Pairwise Random Protocol (PRP) is described. PRP enables adversaries to fairly resolve probabilistic activities, an ability missing from most decentralized DVE security proposals. Thus, this dissertations contribution is to address two of the obstacles for deploying research on decentralized DVE architectures. First, lack of evidence that research results apply to existing DVEs. Second, the lack of security systems combining appropriate security guarantees with acceptable overhead.

Aus Einleitung und Motivation "Die gegenwärtigen Entwicklungen von Head-Mounted Displays (HMD, hier synonym auch als Brille bezeichnet) für Virtual Reality (VR) und Augmented Reality (AR) schaffen ein nie da gewesenes Potential dieser Technologien als Werkzeuge in der Produktentwicklung. Wenngleich VR- und ARAnwendungen keineswegs neu in der Industrie sind, bringt der Fortschritt der Verbraucher-HMDs völlig neue Möglichkeiten. Immersive VR-Systeme bedeuten künftig keine hunderttausend Euro Anschaffung mehr – AR-Brillen dienen zukünftig nicht nur der Erweiterung der Realität mit zweidimensionalen Informationen. Cave Automatic Virtual Environments (CAVE), 360-Grad-Projektoren und interaktive Planungstische sind in der Fabrikplanung teilweise etabliert (Runde et al. 2015). Im Unterschied zu diesen Techniken können HMDs jedoch eine deutlich höhere Immersion ermöglichen, was auch für die Interaktion mit der virtuellen Umgebung von Vorteil sein kann. Das Gefühl der Immersion ist wichtig, um in bestimmten Entwicklungsphasen entsprechende Kriterien besser beurteilen zu können. Primär ist der VR-Einsatz für Bewertungsmerkmale sinnvoll, welche nur qualitativ und nicht quantitativ bewertbar sind (Pawellek 2014). Des Weiteren spielt auch die Eingabetechnologie eine essenzielle Rolle. Um mit virtuellen Elementen interagieren zu können, sollte das Eingabegerät echtzeitfähig und intuitiv sein. ..."

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A virtual environment is a set of surroundings that appears to exist to a user through sensory stimuli provided by a computer. By virtual environment, we mean to include environments supporting the full range from VR to pure reality. A necessity for virtual environments is knowledge of the location of objects in the environment. This is referred to as the tracking problem, which points to the need for accurate and precise tracking in virtual environments. Marker-based tracking is a technique which employs fiduciary marks to determine the pose of a tracked object. A collection of markers arranged in a rigid configuration is called a tracking probe. The performance of marker-based tracking systems depends upon the fidelity of the pose estimates provided by tracking probes. The realization that tracking performance is linked to probe performance necessitates investigation into the design of tracking probes for proponents of marker-based tracking. The challenges involved with probe design include prediction of the accuracy and precision of a tracking probe, the creation of arbitrarily-shaped tracking probes, and the assessment of the newly created probes. To address these issues, we present a pioneer framework for designing conformal tracking probes. Conformal in this work means to adapt to the shape of the tracked objects and to the environmental constraints. As part of the framework, the accuracy in position and orientation of a given probe may be predicted given the system noise. The framework is a methodology for designing tracking probes based upon performance goals and environmental constraints. After presenting the conformal tracking framework, the elements used for completing the steps of the framework are discussed. We start with the application of optimization methods for determining the probe geometry. Two overall methods for mapping markers on tracking probes are presented, the Intermediary Algorithm and the Viewpoints Algorithm. Next, we examine the method used for pose estimation and present a mathematical model of error propagation used for predicting probe performance in pose estimation. The model uses a first-order error propagation, perturbing the simulated marker locations with Gaussian noise. The marker locations with error are then traced through the pose estimation process and the effects of the noise are analyzed. Moreover, the effects of changing the probe size or the number of markers are discussed. Finally, the conformal tracking framework is validated experimentally. The assessment methods are divided into simulation and post-fabrication methods. Under simulation, we discuss testing of the performance of each probe design. Then, post-fabrication assessment is performed, including accuracy measurements in orientation and position. The framework is validated with four tracking probes. The first probe is a six-marker planar probe. The predicted accuracy of the probe was 0.06 deg and the measured accuracy was 0.083 plus/minus 0.015 deg. The second probe was a pair of concentric, planar tracking probes mounted together. The smaller probe had a predicted accuracy of 0.206 deg and a measured accuracy of 0.282 plus/minus 0.03 deg. The larger probe had a predicted accuracy of 0.039 deg and a measured accuracy of 0.017 plus/minus 0.02 deg. The third tracking probe was a semi-spherical head tracking probe. The predicted accuracy in orientation and position was 0.54 plus/minus 0.24 deg and 0.24 plus/minus 0.1 mm, respectively. The experimental accuracy in orientation and position was 0.60 plus/minus 0.03 deg and 0.225 plus/minus 0.05 mm, respectively. The last probe was an integrated, head-mounted display probe, created using the conformal design process. The predicted accuracy of this probe was 0.032 plus/minus 0.02 degrees in orientation and 0.14 plus/minus 0.08 mm in position. The measured accuracy of the probe was 0.028 plus/minus 0.01 degrees in orientation and 0.11 plus/minus 0.01 mm in position. These results constitute an order of magnitude improvement over current marker-based tracking probes in orientation, indicating the benefits of a conformal tracking approach. Also, this result translates to a predicted positional overlay error of a virtual object presented at 1m of less than 0.5 mm, which is well above reported overlay performance in virtual environments.

This dissertation investigated the effects of spatialized auditory cues on the development of situation awareness for teams. Based on extant research, it was hypothesized that 3-D spatialized auditory cues can be utilized by teams to develop knowledge about team member location in addition to supporting the usage of team behaviors for developing and maintaining situation awareness. Accordingly, the study examined how situation awareness would be differentially influenced by varying the type of auditory cues incorporated into virtual environment (VE) team training scenarios within the context of a MOUT team task. In general, the results of this study provided partial support for the beneficial effects of 3-D audio cues in facilitating the development of situation awareness and reducing workload. Implications are discussed in the context of design guidance for VE training systems.

With the help of XR tools, globally dispersed teams can collaborate remotely in shared virtual environments, reducing the costs associated with physical prototypes and travel while benefiting from including stakeholders from various backgrounds in their process. Integrating digital human models in these virtual environments allows for collaborative design interactions and possibilities for performing ergonomic design and assessments. While screen-based tools are the standard for these evaluations, the inclusion of XR tools can augment current screen-based tools to improve the evaluation of ergonomics and the assembleability of components with digital human models. This study describes an implementation model for collaborative assembly simulations, ergonomics assessments, and reviews in a shared virtual environment with XR and screen-based tools. A pilot study with fifteen participants was designed to compare a Swedish/Chinese vehicle manufacturer's approach to simulating and analyzing assembly designs with the collaborative virtual environment model developed. The results show that teams collaborating in a shared virtual environment performed better in user experience, the feeling of presence, and precision when detecting ergonomics and assemblability issues.

The early detection of mild cognitive impairment has the potential to significantly impact the lives of individuals who may be unaware of their cognitive decline. Such a condition can greatly affect their quality of life and ability to perform daily activities. Cognitive screening tests have been developed to identify those who may have cognitive problems or who may be at risk of developing them in the future, aiming to provide appropriate evaluation and treatment. However, a challenge with current tools is the limited correlation often observed between formal tests of executive functions and real-life functioning, which is known as ecological validity. To address this issue, cutting-edge technologies like Virtual Reality can be utilized to assess cognitive functions and increase ecological validity, resulting in more reliable assessments. This study presents a virtual reality application called CE360°VR within which various cognitive functions are examined through tasks, while both quantitative and qualitative data are collected. To achieve this, a set of fourteen scenes has been defined, drawing from standardized tests such as the “Montreal Cognitive Assessment” and the “Mini-Mental State Examination”. The application has been developed using Unity, and the virtual environments are recreated using 360° pictures. The study involves a sample of healthy adults (n=68), aiming to assess the usability and perceived user experience of the Virtual Reality Application. A questionnaire has been administered at the end of the experience including three different standardized scales: System Usability Scale, User Experience Questionnaire, and Affinity for Technology Interaction Scale. According to the results of the study, the Virtual Reality application is classified as “good” with an “acceptable” level of usability, as per the adjective scale developed by Bangor et al. The data collected, which turned into performance indicators of the participants, was found to have no correlation with either the technology affinity or the age. Instead, it was observed that the instruction level of the patients was correlated with their performance. Building upon these findings, a normative study would be necessary to standardize the results and consider this system as a reliable and valid tool for clinical use. / Tidig upptäckt av enklare kognitiv funktionsnedsättning kan påverka livet för individer som kanske är omedvetna om deras kognitiva försämring. Ett sådant tillstånd kan i hög grad påverka deras livskvalitet och förmåga att utföra dagliga aktiviteter. Kognitiva screeningtester har, i syfte att tillhandahålla lämplig utvärdering och behandling, utvecklats för att identifiera personer som har kognitiva problem eller som riskerar att utveckla dem i framtiden. En utmaning med nuvarande verktyg och tester är dess ekologiska validitet eftersom testen ofta visar svag korrelation mellan formella tester av exekutiva kognitiva funktioner och verklig funktion i specifika kontexter. Genom banbrytande teknologier, såsom Virtual Reality (VR), möjliggörs att bedöma kognitiva funktioner och öka ekologisk validitet, vilket kan resultera i mer tillförlitliga bedömningar. Denna studie presenterar en VR-applikation som heter CE360°VR där de formella testerna görs inom välkända kontexter. Både kvantitativ och kvalitativ data samlades in. För att uppnå detta, har en uppsättning av 14 scener har definierats, baserade på ritningar från standardiserade tester som ”Montreal Cognitive Assessment” och ”Mini-Mental State Examination”. Applikationen har utvecklats med Unity, och virtuella miljöer återskapas med 360°-bilder. Studien involverar ett urval av friska vuxna (n=68), som syftar till att bedöma användbarheten och upplevd användarupplevelse av Virtual Reality applikationen. En enkät har besvarats i slutet av testen med hjälp av tre olika standardiserade skalor: System Usability Scale, User Experience Questionnaire och Affinity för Technology Interaction Scale. Resultaten av studien visar att Virtual Reality-applikationen klassificeras som ”bra” med en ”acceptabel” nivå av användbarhet. Datan som insamlades blev till resultatindikatorer för deltagarna, befanns inte ha något samband med vare sig den teknisk läggning eller ålder. Istället observerades att utbildningsnivån hos patienterna var korrelerad med prestation. Utifrån dessa resultat skulle en normativ studie kunna vara nödvändig för att standardisera resultaten och skapa ett system som kan vara tillförlitligt och giltigt verktyg för klinisk användning