Depth estimation is one of the most important problems in computer vision. It has attracted a lot of attention because it has applications in many areas, such as robotics, VR and AR, self-driving cars etc. Using the defocus blur of a camera lens is one of the methods of depth estimation. In this thesis, we have researched this technique in virtual environments. Virtual datasets have been created for this purpose. In this research, we have applied graph cuts and convolutional neural network (DfD-net) to estimate depth from defocus blur using a natural (Middlebury) and a virtual (Maya) dataset. Graph Cuts showed similar performance for both natural and virtual datasets in terms of NMAE and NRMSE. However, with regard to SSIM, the performance of graph cuts is 4% better for Middlebury compared to Maya. We have trained the DfD-net using the natural and the virtual dataset and then combining both datasets. The network trained by the virtual dataset performed best for both datasets. The performance of graph-cuts and DfD-net have been compared. Graph-Cuts performance is 7% better than DfD-Net in terms of SSIM for Middlebury images. For Maya images, DfD-Net outperforms Graph-Cuts by 2%. With regard to NRMSE, Graph-Cuts and DfD-net shows similar performance for Maya images. For Middlebury images, Graph-cuts is 1.8% better. The algorithms show no difference in performance in terms of NMAE. The time DfD-net takes to generate depth maps compared to graph cuts is 500 times less for Maya images and 200 times less for Middlebury images.

Virtual Reality (VR) is a highly evolving domain and is used in anincreasing number of areas in today's society. Among the technologiesassociated with VR and especially mobile VR, is hand tracking and handgesture recognition. Telemedicine is one of the elds where VR is startingto thrive, and so the concept of adding the use of hand gestures came to bein order to explore the possibilities that can come from it. This researchis conducted with the development of a prototype application that usessome of the most emerging technologies. Manomotion's hand trackingand hand gesture recognition algorithms, and Photon's servers and developerkit, which makes multi-user applications achievable, allowed theconceptual idea of the prototype to become reality. In order to test itsusability and how potential users perceive it, a user study with 24 participantswas made, 8 of which were either studying or working in themedical eld. Additional expert meetings and observations from the userstudy also contributed to ndings that helped show how hand gesturescan aect a doctor consultation in Telemedicine. Findings showed thatthe participants thought of the proposed system as a less costly and timesaving solution, and that they felt immersed in the VR. The hand gestureswere accepted and understood. The participants did not have dicultieson learning or executing them, and had control of the prototype environment.In addition, the data showed that participants considered it to beusable in the medical eld in the future.

Les environnements virtuels (EVs) sont de plus en plus utilisés dans le domaine de la recherche et de la clinique avec pour avantage que chaque environnement peut être adapté au besoin du participant mais avec pour inconvénient que la pluralité des variables mesurées lors des tests virtuels rend la performance du sujet de plus en plus difficile à expertiser. L’objectif de la thèse est de proposer une approche permettant de qualifier, de façon la plus pertinente possible, la performance du participant dans un EV en tentant de comprendre la charge mentale associée à chaque technique d’interaction et comment celle-ci peut venir influencer la performance du participant. Cinquante-trois participants ont réalisé des tâches dans un EV avec une des cinq techniques d’interaction disponible : la souris, le gamepad, le Razer Hydra, le Razer Hydra avec un tracking de tête et le Razer Hydra avec un casque de RV. Ils étaient attribués à une des deux conditions de difficulté de la tâche : une facile et une difficile avec des tâches additionnelles. Le rythme cardiaque du participant était enregistré et ceux-ci ont renseigné des questionnaires de charge mentale, présence et cybermalaise. L’expérimentation a permis de mettre en avant que la différence de charge mentale entre les différentes techniques d’interaction est faible et que celle-ci se manifeste plus sensiblement lorsque les techniques sont regroupées par leurs caractéristiques. Ainsi les techniques avec une sélection en 3D et un steering effectué par les mouvements de la tête demande plus de charge mentale. Le degré d’expertise avec l’utilisation d’une technique d’interaction n’est pas lié à une modulation de la charge mentale. Cependant les utilisateurs qualifiés d’experts sont plus à même d’explorer le VMT que les novices. De plus, la charge mentale est plus perçue dans les conditions où la difficulté de la tâche est faible alors que dans le cas où la difficulté de la tâche est élevée, ce sont les problèmes d’utilisabilité des techniques d’interaction qui s’expriment. Les participants qui ont une charge mentale élevée ont un score plus faible que les participants qui ont une faible charge mentale, en particulier lors des tâches qui réclament des fonctions cognitives variées. / Virtual environments (Ves) can be modulated and be adapted to the need of each user but the several variables used during cognitiv assessment during virtual tests give the user’s performance uneasy to expertise. The objective of the thesis is to propose an approach to qualify user performance taking acount of his/her workload during the task realization. Fifty-three participants realiazed tasks in a VE with one of five interaction technique: mouse, gamepad, Razer Hydra, Razer Hydra and head tracking and Razer Hydra and HMD. They participate in one of the two conditions: the easy one or the more difficult with additionnal tasks. Heart rate, workload, presence and cybersickness were measured. Results showed that there is only a weak difference of workload accross the several interaction technique and the difference is stronger when interaction technique are grouped according their similiarities. Interaction with 3D selection and with head steering ask for more workload. User habilities with the use of an interaction technique is not related to workload but experts are more likely to explore the VE. What’s more the perceived workload is higher in easy condition whereas usability issues are perceived higher in hard condition. Users with high workload have lower score than those with low workload especially for tasks with high cognitiv demand.

How the artist deals with death, loss and the spiritual has been a major theme of art throughout history. New media tools provide renewed opportunity to explore these themes while testing the tools against a familiar subject. This research attempts to deal with these themes by examining and reinterpreting them through myths while evaluating the tools of creative media. In so doing, this has the potential to uncover any revealing insights that are relevant to the times. The project uses myth to explore the potential of the interaction between 2D digital images and 3D virtual environments. Elements of particular significance in the 3D virtual environment - such as Lighting and Point of View - are examined from the perspective of an artist who has practised only in 2D. Twelve final works have been generated for this project and presented as large-scale digital prints, along with a short video piece. In particular, the research explores 3D lighting techniques of 2D images by applying theatrical protocols within a virtual, computer-generated environment, and using myth as context and driving principle. The idea of theatre 'flats' has been applied as a device within the virtual realm to provide a conceptual housing and rationale for virtual lighting techniques, virtual camera techniques, digital rendering and digital printing.

In complex environments, increasing demand for exploring natural resources by both decision makers and the public is driving the search for sustainable planning initiatives. Among these is the use of virtual environments to support effective communication and informed decision-making. Central to the use of virtual environments is their development at low cost and with high realism. / This paper explores intelligent approaches to objects placement, orientation and scaling in virtual environments such that the process is both accurate and cost-effective. The work involves: (1) determining of the key rules to be applied for the classification of vegetation objects and the ways to build an object library according to ecological classes; (2) exploring rules for the placement of vegetation objects based on vegetation behaviours and the growth potential value collected for the research area; (3) developing GIS algorithms for implementation of these rules; and (4) integrating of the GIS algorithms into the existing SIEVE Direct software in such a way that the rules find expression in the virtual environment. / This project is an extension of an integrated research project SIEVE (Spatial Information Exploration and Visualization Environment) that looks at converting 2D GIS data into 3D models which are used for visualization. The aims of my contribution to this research are to develop rules for the classification and intelligent placement of objects, to build a normative object database for rural objects and to output these as 2D billboards or 3D models using the developed intelligent placement algorithms. / Based on Visual Basic Language and ArcObjects tools (ESRI ArcGIS and Game Engine), the outcomes of the intelligent placement process for vegetation objects are shown in the SIEVE environment with 2D images and 3D models. These GIS algorithms were tested in the integrated research project. According to the case study in Victoria, rule-based intelligent placement is based on the idea that certain decision-making processes can be codified into rules which, if followed automatically, would yield results similar to those which would occur in the natural environment. Final product produces Virtual Reality (VR) scenes similar to the natural landscapes. Considering the 2D images and 3D models represented in the SIEVE scenario and the rules (for natural and plantation vegetation) developed in conjunction with scientists in the Victorian Department of Primary Industries (DPI) and other agencies, outcomes will contribute to the development of policies for better land and resource management and link to wide ranging vegetation assessment projects.

<p>When developing the driver interface in their trucks, Scania is highly concerned with creating a certain feeling. When pressing a push-button this Scania feeling shall be perceived. It is not obvious what the Scania feeling really is and there is no predefined method to create it. This Master Thesis takes aim at providing the means to improve the process of creating this feeling.</p><p>First, the Scania feeling was studied via the results of an already made survey at Scania. This survey focused on subjective properties of push-buttons, rotary knobs and levers and related the properties to whether these objects had a Scania feeling or not. This existing data was analyzed statistically. The main task of this Master Thesis, however, was to create an environment where the feeling of a push-button could be tried out and described. This environment was created with a tool from Reachin Technologies AB. The environment is a virtual representation of a push-button module, created with computer haptics and graphics. The environment lets the user interact with a three dimensional view collocated with a force feedback device. The force feedback device lets the user feel what is seen through a pen like interface. The “tip” of the pen is used to touch what is seen in the 3D view. The virtual push-buttons was built from blueprints of real push-buttons to be able to evaluate to what extent the virtual buttons resembled the real ones.</p><p>The statistical analysis made in this project does not support the notion of describing the Scania feeling with a set of subjective values. The virtual environment created proved to be very life like. The real push-button feeling could be recreated with high precision. When evaluated, the majority of test persons argued that it could be used in the development process.</p>

Several researchers have successfully developed realistic models of real world objects/ phenomena and then have simulated them in the virtual world. In this thesis, we propose the opposite: instantiating virtual world events in the real world. The interactive 3D virtual environment provides a useful, realistic 3D world that resembles objects/phenomena of a real world, but it has limited capability to communicate with the physical environment. We argue that new and intuitive 3D user interfaces, such as 3D virtual environment interfaces, may provide an alternative form of media for communicating with the real environment. We propose a 3D virtual world-based add-on architecture that achieves a synchronized virtual-real communication. In this framework, we explored the possibilities of integrating haptic and real world object interactions with Linden Lab's multiuser online 3D virtual world, Second Life. We enhanced the open source Second Life viewer client in order to facilitate communications between the real and virtual world. Moreover, we analyzed the suitability of such an approach in terms of user perception, intuition and other common parameters. Our experiments suggest that the proposed approach not only demonstrates a more intuitive mode of communication system, but also is appealing and useful to the user. Some of the potential applications of the proposed approach include remote child-care, communication between distant lovers, stress recovery, and home automation.

In this thesis, we propose a new design of privacy and session control for improving a collaborative molecular modeling CVR system AMMP-VIS [1]. The design mainly addresses the issue of competing user interests and privacy protection coordination. Based on our investigation of AMMP-VIS, we propose a four-level access control structure for collaborative sessions and dynamic action priority specification for manipulations on shared molecular models. Our design allows a single user to participate in multiple simultaneous sessions. Moreover, a messaging system with text chatting and system broadcasting functionality is included. A 2D user interface [2] for easy command invocation is developed in Python. Two other key aspects of system implementation, the collaboration Central deployment and the 2D GUI for control are also discussed. Finally, we describe our system evaluation plan which is based on an improved cognitive walkthrough and heuristic evaluation as well as statistical usage data.

As a type of virtual learning community, multi-user virtual environments (MUVEs) are not only sources of entertainment but are also places where learning opportunities and community development can be created and fostered. Some multi-user virtual environments that have emerged have been designed to serve students and teachers in the K-12 sector. Although learning is a goal in these contexts, this study focused on some of the community building and social networking components. The purpose of this study was to examine whether, to what degree and how nine elementary aged students projected themselves socially through this medium. The results could provide insight into the integration of such environments into K-12 educational contexts and could serve as a launching point for further research into the learning and community aspects of MUVEs. A case study approach was used in this research study. The researcher chose a class of nine students who were enrolled in an educational MUVE as part of their regular studies. Although these students completed assignments in the MUVE, only their social interactions were analyzed. The data was collected from student communication logs in the educational MUVE Quest Atlantis and from interviews with participants. Document analysis was used to analyze transcripts of student communications in Quest Atlantis as well as transcripts from text-based interviews. The results obtained demonstrate the types of communication and tool selection patterns of elementary aged students when using text to communicate in a MUVE and provide insight that can be used by teachers to inform the integration of MUVEs in their unique learning contexts. Findings indicated that frequency of communication varied substantially between participants but message content was similar and content volume varied depending on the communication tool. Gender differences were pronounced. Results also revealed that all participants were comfortable and enjoyed their involvement in the MUVE.

Several researchers have successfully developed realistic models of real world objects/ phenomena and then have simulated them in the virtual world. In this thesis, we propose the opposite: instantiating virtual world events in the real world. The interactive 3D virtual environment provides a useful, realistic 3D world that resembles objects/phenomena of a real world, but it has limited capability to communicate with the physical environment. We argue that new and intuitive 3D user interfaces, such as 3D virtual environment interfaces, may provide an alternative form of media for communicating with the real environment. We propose a 3D virtual world-based add-on architecture that achieves a synchronized virtual-real communication. In this framework, we explored the possibilities of integrating haptic and real world object interactions with Linden Lab's multiuser online 3D virtual world, Second Life. We enhanced the open source Second Life viewer client in order to facilitate communications between the real and virtual world. Moreover, we analyzed the suitability of such an approach in terms of user perception, intuition and other common parameters. Our experiments suggest that the proposed approach not only demonstrates a more intuitive mode of communication system, but also is appealing and useful to the user. Some of the potential applications of the proposed approach include remote child-care, communication between distant lovers, stress recovery, and home automation.