Year after year, technologies are evolving in an incredible rapid pace, becoming faster, more complex, more accurate and more immersive. Looking back just a decade, especially interaction technologies have made a major leap. Just two years ago in 2013, after being researched for quite some time, the hype around virtual reality (VR) arouse renewed enthusiasm, finally reaching mainstream attention as the so called head-mounted displays (HMD), devices worn on the head  to grant a visual peek into the virtual world, gain more and more acceptance with the end-user. Currently, humans interact with computers in a very counter-intuitive two dimensional way. The ability to experience digital content in the humans most natural manner, by simply looking around and perceiving information from their surroundings, has the potential to be a major game changer in how we perceive and eventually interact with digital information. However, this confronts designers and developers with new challenges of how to apply these exciting technologies, supporting interaction mechanisms to naturally explore digital information in the virtual world, ultimately overcoming real world boundaries. Within the virtual world, the only limit is our imagination. This thesis investigates an approach of how to naturally interact and explore information based on open data within an immersive virtual reality environment using a head-mounted display and vision-based motion controls. For this purpose, an immersive VR application visualizing information as a network of European capital cities has been implemented, offering interaction through gesture input. The application lays a major focus on the exploration of the generated network and the consumption of the displayed information. While the conducted user interaction study with eleven participants investigated their acceptance of the developed prototype, estimating their workload and examining their explorative behaviour, the additional dialog with five experts in the form of explorative discussions provided further feedback towards the prototype’s design and concept. The results indicate the participants’ enthusiasm and excitement towards the novelty and intuitiveness of exploring information in a less traditional way than before, while challenging them with the applied interface and interaction design in a positive manner. The design and concept were also accepted through the experts, valuing the idea and implementation. They provided constructive feedback towards the visualization of the information as well as emphasising and encouraging to be even bolder, making more usage of the available 3D environment. Finally, the thesis discusses these findings and proposes recommendations for future work.

[pt] Ao longo dos anos, muitos estudos têm explorado o potencial das tecnologias de realidade virtual para apoiar o trabalho colaborativo, em especial para aplicações de treinamento e simulação. Com o uso de um ambiente virtual, é possível criar aplicações para simulação e treinamento capazes de representar cenas reais, permitindo também aumentar a flexibilidade para fazer mudanças estruturais em objetos e outros aspectos do cenário virtual, para, por exemplo, simular situações de emergência e acidentes, difíceis de serem simuladas em um cenário real. Este trabalho estuda o uso da colaboração em ambientes imersivos para dar suporte a treinamentos de usuários. O modelo de colaboração 3C (comunicação, cooperação e coordenação) foi utilizado para modelar e definir as ferramentas de colaboração no desenvolvimento de um aplicativo de realidade virtual colaborativo. O modelo 3C define que em um ambiente de colaboração os indivíduos necessitam trocar informações (comunicação) e se organizarem (coordenação) para que possam trabalhar em conjunto em ambiente compartilhado (cooperação). Para este trabalho foi implementado um programa de treinamento colaborativo entre um usuário imerso em uma CAVE e um usuário remoto não imerso, usando um computador de desktop. Foram implementadas técnicas para ajudar os usuários a realizar a colaboração: waypointing e highlight. Para ajudar o wayfinding, que é o processo cognitivo de definir um caminho através de um ambiente utilizando e adquirindo conhecimento espacial, auxiliado por pistas naturais e artificiais, era permitido ao usuário do desktop posicionar waypoints, pistas artificiais que permitiam a definição de um caminho até o objetivo da tarefa. O highlight consiste na aplicação de uma silhueta nos objetos, destacando-os, permitindo identificar os objetos a serem selecionados com facilidade. Uma série de testes foi elaborada, tendo como principal objetivo avaliar o cenário heterogêneo de colaboração, verificando aspectos como: importância e eficácia da comunicação por áudio, necessidade da comunicação por texto e papel das técnicas auxiliares (highlight e waypointing) como eventuais substitutos ou complementares às técnicas de comunicação, em tarefas baseadas em situações reais com diferentes níveis de complexidade. / [en] Throughout the years, many studies have explored the potential of virtual reality technologies to support collaborative work, particularly for training and simulation applications. By using a virtual environment, it is possible to create applications for simulation and training capable of representing real scenes, which also allow more flexibility to make structural changes to objects and other aspects of the virtual scenario to simulate, for instance, emergency situations and accidents, which are difficult to simulate in a real scenario. This work studies the use of collaboration in immersive environments to support user training. The 3C collaboration model (communication, cooperation and coordination) was used to define the model and collaboration tools in the development of a collaborative virtual reality application. The 3C model defines that in a collaborative environment individuals need to exchange information (communication) and organize (coordination) so they can work together in a shared environment (cooperation). For this work we implemented a collaborative training program between a user immersed in a CAVE and a remote user using a desktop computer. We implement techniques to help users accomplish collaboration: waypointing and highlight. To assist wayfinding, which is the cognitive process of defining a path through an environment using and acquiring spatial knowledge, aided by natural and artificial slopes, it was allowed to the desktop user to create waypoints, artificial slopes that allowed the definition of a path to the task goal. The highlight consists of the application of a silhouette on objects, highlighting them, allowing the users to easily identify the objects of interest. A series of tests was developed with the main objective of evaluating the heterogeneous scenario for collaboration, checking aspects such as: importance and effectiveness of audio communication, text communication need and the role of auxiliary techniques (highlight and waypointing) as eventual substitutes or complements techniques of communication in tasks based on real situations with different levels of complexity.

La participation citoyenne (PC) est aujourd’hui au cœur de nombreux discours mais peine à s’imposer dans les institutions publiques. Dans le cas du design urbain (DU), des initiatives encourageantes peuvent être observées. Néanmoins, les observations amènent aussi à remarquer que les méthodologies actuellement utilisées reposent majoritairement sur des outils artisanaux. Cette thèse se concentre sur l’intégration d’outils numériques dans le processus de participation citoyenne dans l’aménagement des espaces publics. Plus particulièrement, les travaux sont centrés sur un mode de concertation collaboratif appliquant les concepts du co-design, qui vise à rassembler citoyens et professionnels du design urbain dans un même lieu, pour bâtir un langage commun et une vision partagée. Au travers d’une méthodologie de recherche basée sur la design science, cette recherche transdisciplinaire considère à la fois le contexte d’application, et les théories dans le domaine de la PC numérique et du co-design. En effet, il est mis en avant que les travaux de recherche existants soient soit trop théoriques dans le domaine de la PC et ne proposent pas l’instanciation et l’évaluation d’un artefact à travers un prototype, soit trop centrés sur la technologie en laissant de côté le contexte d’application. De plus, afin de combler un manque dans l’état de l’art actuel, un accent particulier est mis sur l’amélioration des capacités d’expression créative des citoyens par le co-design, et la réalisation d’une interface intuitive dédiée aux amateurs. / Citizen participation (CP) is today at the heart of many speeches but struggles to impose itself in public institutions. In the case of urban design (DU), encouraging initiatives can be observed. Nevertheless, observations also point out that the methodologies currently used are mainly based on artisanal tools. This thesis focuses on the integration of digital tools in the process of citizen participation in the development of public spaces. More specifically, the work focuses on a collaborative approach that applies the concepts of co-design, which aims to bring citizens and urban design professionals together in one place, to build a common language and a shared vision. Through a research methodology based on design science, this transdisciplinary research considers both the context of application, and theories in the field of digital CP and co-design. It is emphasized that the existing research work is either too theoretical in the field of PC and do not propose the instantiation and the evaluation of an artifact through a prototype, or too centered on the technology, leaving aside the context of application. In addition, in order to fill a gap in the current state of the art, a special emphasis is placed on improving citizens' creative expression abilities through co-design, and the realization of an intuitive interface dedicated to amateurs.

A integração on-line de dados reais com ambientes de realidade virtual imersivos, criando sistemas híbridos, é um campo de pesquisa multidisciplinar, ainda pouco explorado. O alto nível de envolvimento do usuário proporcionado pela realidade virtual imersiva e a confiabilidade e precisão de informações provenientes da aquisição de dados reais, de maneira on-line, podem auxiliar o processo de tomada de decisão, em diversas áreas de aplicação. Este trabalho apresenta uma metodologia de integração on-line de dados reais de manufatura com ambientes de realidade virtual imersivos, mais especificamente, com sistemas CAVE. A metodologia foi desenvolvida voltada para a área de manufatura virtual, com foco em máquinas-ferramenta. Foram criados e interligados dois métodos de aquisição de dados on-line, um deles específico para máquinas-ferramenta, através do protocolo MTConnect e outro, genérico, via imagens de câmeras. O trabalho foi desenvolvido, em geral, com base em bibliotecas e softwares livres, bem como com dispositivos de baixo custo. Por fim, avaliou-se a metodologia através de estudos de caso, baseados em dados reais on-line, provenientes de máquinas-ferramenta reais e de simuladores de dados de máquinas reais. Os resultados deste trabalho podem auxiliar o desenvolvimento de ferramentas que aumentem do nível de confiabilidade das tomadas de decisões baseadas em simulações virtuais da área de manufatura. E, devido à sua implementação modular, ao formato hierárquico e unificado de sua estrutura e à padronização de seus tipos de dados, comunicações e formas de utilização, pode ser adequada a quaisquer áreas de aplicação que utilizem integração de dados reais on-line com ambientes virtuais imersivos. / The on-line integration of real manufacturing data with immersive virtual reality environments, forming hybrid systems, is an underexplored multidisciplinary research field. The high level of users\' involvement provided by immersive virtual reality and the reliability and accuracy of information acquired on-line from real data, can assist the decision making process, in many research areas. This research presents a way to on-line integrate manufacturing real data with immersive virtual reality environments, more specifically, with CAVEs. This work was developed toward the area of virtual manufacturing, with focus on machine tools. Two data acquisition methods were created and placed to work together, one specific for machine tools, through the MTConnect protocol and the other, generic, through camera images acquisition. This work was based on free libraries and software, as well as low cost devices. Finally, this work was evaluated through case studies, based on on-line real data, from real machine tools and real machine data simulators. The results achieved with this research can contribute to the development of new tools to increase the reliability level of manufacturing virtual simulations. Moreover, due to its modular implementation, the hierarquical and unified structure format and the standardization of its communication methods and data types, it can be arranged to almost any research areas which use integration of real on-line data with immersive virtual environments.

" We designed an interactive 3D user interface system to perform object modeling in virtual environments. Expanding on existing 3D user interface techniques, we integrate low-cost human gesture recognition that endows the user with powerful abilities to perform complex virtual object modeling tasks in an immersive game setting. Much research has been done to explore the possibilities of developing biosensors for Virtual Reality (VR) use. In the game industry, even though full body interaction techniques are involved in modern game consoles, most of the utilizations, in terms of game control, are still simple. In this project, we extended the use of motion tracking and gesture recognition techniques to create a new 3D UI system to support immersive gaming. We set a goal for the usability, which is virtual object modeling, and finally developed a game application to test its performance. "

La création des vidéos panoramiques de haute qualité pour des contenus immersifs en VR est généralement faite à l'aide d'un appareil doté de plusieurs caméras couvrant une scène cible. Malheureusement, cette configuration introduit à la fois des artefacts spatiaux et temporels dus à la différence entre les centres optiques et à la synchronisation imparfaite. Les mesures de qualité d'image traditionnelles ne peuvent pas être utilisées pour évaluer la qualité de ces vidéos, en raison de leur incapacité à capturer des distorsions géométriques. Dans cette thèse, nous proposons des méthodes pour l'évaluation objective des vidéos panoramiques basées sur le flux optique et la saillance visuelle. Nous validons cette métrique avec une étude centrée sur l'homme qui combine l'annotation d'erreurs percues et l'eye-tracking.Un défi important pour mesurer la qualité des vidéos panoramiques est le manque d'une vérité-terrain. Nous avons étudié l'utilisation des vidéos originales comme référence pour le panorama de sortie. Nous notons que cette approche n'est pas directement applicable, car chaque pixel du panorama final peut avoir une à $N$ sources correspondant à $N$ vidéos d'entrée avec des régions se chevauchant. Nous montrons que ce problème peut être résolu en calculant l'écart type des déplacements de tous les pixels sources à partir du déplacement du panorama en tant que mesure de la distorsion. Cela permet de comparer la différence de mouvement entre deux images données dans les vidéos originales et le mouvement dans le panorama final. Les cartes de saillance basées sur la perception humaine sont utilisées pour pondérer la carte de distorsion pour un filtrage plus précis.Cette méthode a été validée par une étude centrée sur l'homme utilisant une expérience empirique. L'expérience visait à déterminer si les humains et la métrique d'évaluation détectaient et mesuraient les mêmes erreurs, et à explorer quelles erreurs sont les plus importantes pour les humains lorsqu'ils regardent une vidéo panoramique.Les méthodes décrites ont été testées et validées et fournissent des résultats intéressants en ce qui concerne la perception humaine pour les mesures de qualité. Ils ouvrent également la voie à de nouvelles méthodes d'optimisation de l'assemblage vidéo, guidées par ces mesures de qualité. / High quality panoramic videos for immersive VR content are commonly created using a rig with multiple cameras covering a target scene. Unfortunately, this setup introduces both spatial and temporal artifacts due to the difference in optical centers as well as the imperfect synchronization. Traditional image quality metrics cannot be used to assess the quality of such videos, due to their inability to capture geometric distortions. In this thesis, we propose methods for the objective assessment of panoramic videos based on optical flow and visual salience. We validate this metric with a human-centered study that combines human error annotation and eye-tracking.An important challenge in measuring quality for panoramic videos is the lack of ground truth. We have investigated the use of the original videos as a reference for the output panorama. We note that this approach is not directly applicable, because each pixel in the final panorama can have one to N sources corresponding to N input videos with overlapping regions. We show that this problem can be solved by calculating the standard deviation of displacements of all source pixels from the displacement of the panorama as a measure of distortion. This makes it possible to compare the difference in motion between two given frames in the original videos and motion in the final panorama. Salience maps based on human perception are used to weight the distortion map for more accurate filtering.This method was validated with a human-centered study using an empirical experiment. The experiment was designed to investigate whether humans and the evaluation metric detect and measure the same errors, and to explore which errors are more salient to humans when watching a panoramic video.The methods described have been tested and validated and they provide interesting findings regarding human-based perception for quality metrics. They also open the way to new methods for optimizing video stitching guided by those quality metrics.

Made available in DSpace on 2016-04-26T18:18:09Z (GMT). No. of bitstreams: 1 Isabela Pereira Barros.pdf: 896920 bytes, checksum: 7808554fc79e449ddf13c25ec1db84a9 (MD5) Previous issue date: 2009-08-28 / The research "To the Press Office of the Diary - A review of the letters from readers of the Diário de S. Paulo" aims to conduct a semiotic analysis of the discourse of the newspaper dai1y readers of the newspaper and further understanding, through semiotic examination, the relation between those and the newspaper. The choice of the Diário is justified by the popular character of the newspaper and its experience in this field through the years (125). Hence, By maping these readers reactions, their points and requirements it will be possible to understand what place has the newspaper achieved in their lives. Additionally, it aims to analise if the responses of the readers make new topics emerge on the daily draft of the newspaper. The concept of immersive reader will be used in this research as a fundamental point of analisis of the point of views of the readers who found themselves embraced by a new concept of reading, marked by the interactivity of the ciber space.Thus, the comparison between the attitude of readers of a newspaper printed and readers of blogs on the intemet will be crucial to this work as it examines the changes brought by intemet and the immersive lector that it introduces. The corpus of this research is composed by a selection of letters to the Diário de S. Paulo. It will be considered the letters published in 2007, 2008 and 2009 (from January to March). The reactions of the readers after cases of great commotion, related to religion, sexuality and policies. The methodology involves the discourse analyisis of the contents of the letters and also the newspaper that are connected, as well as bibliographic and documentary literature. Among the authors selected as main references are Roland Barthes, Eugênio Bucci, Lúcia Santaella and José Luiz Fiorin / A pesquisa "À redação do Diário - uma análise das cartas dos leitores do Diário de S. Paulo" objetiva realizar uma análise semiótica do discurso dos missivistas do jornal Diário de S. Paulo e entender através desse exame semiótico a relação que se estabelece entre eles e o jornal. A escolha do Diário de S. Paulo justifica-se pelo caráter popular do jornal e pela sua antiguidade (125 anos). Mais especificamente, trata-se de avaliar se os conteúdos veiculados pelo jornal são considerados relevantes para esses leitores e de descobrir que temas geram cartas. Será verificado se as demandas variam em função do momento político, a que tipo de noticiário reage o leitor interativo. Analisar como esses missivistas reagem e se essas respostas lançam novos temas na agenda do periódico. Ao mapear a enunciação dos leitores, seus temas e demandas, será possível entender que espaço é o jornal para os seus missivistas. Ponto fundamental para esta pesquisa, o conceito de leitor imersivo será utilizado para analisar a postura do leitor que se vê diante de um novo modo de ler, marcado pela interatividade do ciberespaço. Assim, a comparação entre a postura dos leitores de um jornal impresso e dos leitores de blogs na internet será fundamental para este trabalho na medida em que analisa as transformações trazidas pela internet e pelo leitor imersivo que ela introduz. O corpus da pesquisa é constituído por uma seleção de cartas enviadas ao Diário de S. Paulo. Serão consideradas as cartas publicadas em 2007, 2008 e nos três primeiros meses de 2009: janeiro, fevereiro e março. Serão analisadas as cartas cujo conteúdo esteja relacionado a três temas: religião, sexualidade e política. O objetivo é acompanhar às reações dos leitores diante de casos recentes de grande repercussão local e nacional, sempre a partir dos temas delimitados; analisar como esses missivistas reagem e se essas respostas geram novos temas na agenda do jornal; mapear a enunciação desse grupo de leitores. A metodologia envolverá a análise do discurso das cartas e dos textos do jornal que têm ligação com essas, pesquisa bibliográfica e documental. Entre os autores selecionados como referência teórica estão Roland Barthes, Eugênio Bucci e Lúcia Santaella

A integração on-line de dados reais com ambientes de realidade virtual imersivos, criando sistemas híbridos, é um campo de pesquisa multidisciplinar, ainda pouco explorado. O alto nível de envolvimento do usuário proporcionado pela realidade virtual imersiva e a confiabilidade e precisão de informações provenientes da aquisição de dados reais, de maneira on-line, podem auxiliar o processo de tomada de decisão, em diversas áreas de aplicação. Este trabalho apresenta uma metodologia de integração on-line de dados reais de manufatura com ambientes de realidade virtual imersivos, mais especificamente, com sistemas CAVE. A metodologia foi desenvolvida voltada para a área de manufatura virtual, com foco em máquinas-ferramenta. Foram criados e interligados dois métodos de aquisição de dados on-line, um deles específico para máquinas-ferramenta, através do protocolo MTConnect e outro, genérico, via imagens de câmeras. O trabalho foi desenvolvido, em geral, com base em bibliotecas e softwares livres, bem como com dispositivos de baixo custo. Por fim, avaliou-se a metodologia através de estudos de caso, baseados em dados reais on-line, provenientes de máquinas-ferramenta reais e de simuladores de dados de máquinas reais. Os resultados deste trabalho podem auxiliar o desenvolvimento de ferramentas que aumentem do nível de confiabilidade das tomadas de decisões baseadas em simulações virtuais da área de manufatura. E, devido à sua implementação modular, ao formato hierárquico e unificado de sua estrutura e à padronização de seus tipos de dados, comunicações e formas de utilização, pode ser adequada a quaisquer áreas de aplicação que utilizem integração de dados reais on-line com ambientes virtuais imersivos. / The on-line integration of real manufacturing data with immersive virtual reality environments, forming hybrid systems, is an underexplored multidisciplinary research field. The high level of users\' involvement provided by immersive virtual reality and the reliability and accuracy of information acquired on-line from real data, can assist the decision making process, in many research areas. This research presents a way to on-line integrate manufacturing real data with immersive virtual reality environments, more specifically, with CAVEs. This work was developed toward the area of virtual manufacturing, with focus on machine tools. Two data acquisition methods were created and placed to work together, one specific for machine tools, through the MTConnect protocol and the other, generic, through camera images acquisition. This work was based on free libraries and software, as well as low cost devices. Finally, this work was evaluated through case studies, based on on-line real data, from real machine tools and real machine data simulators. The results achieved with this research can contribute to the development of new tools to increase the reliability level of manufacturing virtual simulations. Moreover, due to its modular implementation, the hierarquical and unified structure format and the standardization of its communication methods and data types, it can be arranged to almost any research areas which use integration of real on-line data with immersive virtual environments.

Les données d'aujourd'hui deviennent de plus en plus complexes à cause de la forte croissance de leurs volumes ainsi que leur multidimensionnalité. Il devient donc nécessaire d'explorer des environnements d'affichage qui aillent au-delà du simple affichage de données offert par les moniteurs traditionnels et ce, afin de fournir une plus grande surface d'affichage ainsi que des techniques d'interaction plus performantes pour l'exploration de données. Les environnements correspondants à cette description sont les suivants : Les écrans large ; les environnements multi-écrans (EME) composés de plusieurs écrans hétérogènes spatialement distribués (moniteurs, smartphones, tablettes, table interactive ...) ; les environnements immersifs. Dans ce contexte, l'objectif de ces travaux de thèse est de concevoir et d'évaluer des solutions d'interaction originales, efficaces et adaptées à chacun des trois environnements cités précédemment. Une première contribution de nos travaux consiste en Split-focus : une interface de visualisation et d'interaction qui exploite les facilités offertes par les environnements multi-écrans dans la visualisation de données multidimensionnelles au travers d'une interface overview + multi-detail multi-écrans. Bien que plusieurs techniques d'interaction offrent plus d'une vue détaillée en simultané, le nombre optimal de vues détaillées n'a pas été étudié. Dans ce type d'interface, le nombre de vues détaillées influe grandement sur l'interaction : avoir une seule vue détaillée offre un grand espace d'affichage mais ne permet qu'une exploration séquentielle de la vue d'ensemble?; avoir plusieurs vues détaillées réduit l'espace d'affichage dans chaque vue mais permet une exploration parallèle de la vue d'ensemble. Ce travail explore le bénéfice de diviser la vue détaillée d'une interface overview + detail pour manipuler de larges graphes à travers une étude expérimentale utilisant la technique Split-focus. Split-focus est une interface overview + multi-détails permettant d'avoir une vue d'ensemble sur un grand écran et plusieurs vues détaillées (1,2 ou 4) sur une tablette. [...] / Today's ever-growing data is becoming increasingly complex due to its large volume and high dimensionality: it thus becomes crucial to explore interactive visualization environments that go beyond the traditional desktop in order to provide a larger display area and offer more efficient interaction techniques to manipulate the data. The main environments fitting the aforementioned description are: large displays, i.e. an assembly of displays amounting to a single space; Multi-display Environments (MDEs), i.e. a combination of heterogeneous displays (monitors, smartphones/tablets/wearables, interactive tabletops...) spatially distributed in the environment; and immersive environments, i.e. systems where everything can be used as a display surface, without imposing any bound between displays and immersing the user within the environment. The objective of our work is to design and experiment original and efficient interaction techniques well suited for each of the previously described environments. First, we focused on the interaction with large datasets on large displays. We specifically studied simultaneous interaction with multiple regions of interest of the displayed visualization. We implemented and evaluated an extension of the traditional overview+detail interface to tackle this problem: it consists of an overview+detail interface where the overview is displayed on a large screen and multiple detailed views are displayed on a tactile tablet. The interface allows the user to have up to four detailed views of the visualization at the same time. We studied its usefulness as well as the optimal number of detailed views that can be used efficiently. Second, we designed a novel touch-enabled device, TDome, to facilitate interactions in Multi- display environments. The device is composed of a dome-like base and provides up to 6 degrees of freedom, a touchscreen and a camera that can sense the environment. [...]

This work aims at providing some cues in order to address the essential requirements about the design of 3D Collaborative Virtual Environments (CVE). We have identified six essential topics that must be addressed when designing a CVE. For each of them, we present a state of the art about the solutions that can address this topic, then we show our own contributions: how we improve existing solutions and what are our new propositions. 1 - Choosing a model for the distribution of a CVE We need a distribution model to distribute as efficiently as possible the content of a CVE among all the nodes involved in its execution, including the machines of the distant users. Our proposition is to allow CVE designers to mix in a same CVE the three main distribution models usually encountered: centralized on a server, totally replicated on each site, or distributed according to a hybrid distribution model. 2 - Choosing a model for the synchronization of these nodes To maintain consistency between all the nodes involved in the execution of a CVE, we must choose between a strong synchronization or a relaxed one, or an in-between solution. Our proposition is to manage some temporary relaxation of the synchronization due to network breakdowns, with several synchronization groups of users, making them aware of these network breakdowns, and to allow some shared objects to migrate from one site to another. 3 - Adapting the Virtual Environment to various hardware systems VR applications must be adapted to the software and to the hardware input and output devices that are available at run-time, in order to be able to deploy a CVE onto di fferent kinds of hardware and software. Our solution is the PAC-C3D software architectural model which is able to deal with the three main distribution modes encountered in CVE. 4 - Designing interaction and collaboration in the VE Expressing the interactive and collaborative capabilities of the content of a CVE goes one step beyond geometric modeling, by adding interactive and collaborative features to virtual objects. We propose a unified model of dialog between interactive objects and interaction tools, with an extension to Collada in order to describe interactive and collaborative properties of these interactive objects and interaction tools. 5 - Choosing the best metaphors for collaborative interactions Most of the time single-user interaction tools and metaphors are not adapted to off er effi cient collaboration between users of a CVE. We adapt some of these tools and metaphors to collaborative interactions, and we propose new really collaborative metaphors to enhance real multi-user collaborative interactions, with dedicated collaborative feedback. 6 - Embedding the users' physical workspaces within the CVE Taking into account users' physical workspaces makes it possible to adapt a CVE to the hardware input and output devices of the users, and to make them aware of their physical limitations and of those of the other users, for better interaction and collaboration. We propose the Immersive Interactive Virtual Cabin (IIVC) concept to embed such 3D representations in CVE.