Animating an articulated figure usually requires expensive hardware in terms of motion capture equipment, processing power and rendering power. This implies a high cost system and thus eliminates the use of personal computers to drive avatars in virtual environments. We propose a system to animate an articulated human upper body in real-time, using minimal motion capture trackers to provide position and orientation for the limbs. The system has to drive an avatar in a virtual environment on a low-end computer. The cost of the motion capture equipment must be relatively low (hence the use of minimal trackers). We discuss the various types of motion capture equipment and decide to use electromagnetic trackers which are adequate for our requirements while being reasonably priced. We also discuss the use of inverse kinematics to solve for the articulated chains making up the topology of the articulated figure. Furthermore, we offer a method to describe articulated chains as well as a process to specify the reach of up to four link chains with various levels of redundancy for use in articulated figures. We then provide various types of constraints to reduce the redundancy of non-defined articulated chains, specifically for chains found in an articulated human upper body. Such methods include a way to solve for the redundancy in the orientation of the neck link, as well as three different methods to solve the redundancy of the articulated human arm. The first method involves eliminating a degree of freedom from the chain, thus reducing its redundancy. The second method calculates the elevation angle of the elbow position from the elevation angle of the hand. The third method determines the actual position of the elbow from an average of previous positions of the elbow according to the position and orientation of the hand. The previous positions of the elbow are captured during the calibration process. The redundancy of the neck is easily solved due to the small amount of redundancy in the chain. When solving the arm, the first method which should give a perfect result in theory, gives a poor result in practice due to the limitations of both the motion capture equipment and the design. The second method provides an adequate result for the position of the redundant elbow in most cases although fails in some cases. Still it benefits from a simple approach as well as very little need for calibration. The third method provides the most accurate method of the three for the position of the redundant elbow although it also fails in some cases. This method however requires a long calibration session for each user. The last two methods allow for the calibration data to be used in latter session, thus reducing considerably the calibration required. In combination with a virtual reality system, these processes allow for the real-time animation of an articulated figure to drive avatars in virtual environments or for low quality animation on a low-end computer.

Made available in DSpace on 2014-06-11T19:24:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-30Bitstream added on 2014-06-13T20:12:04Z : No. of bitstreams: 1 gasperini_r_me_bauru.pdf: 2885899 bytes, checksum: ba50db0f1568ced891c92f809e88edf8 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A ergonomia está cada vez mais presente no desenvolvimento do produto e consequentemente no processo produtivo. As empresas estão sentindo que o investimento em ergonomia é de suma importância na preservação da saúde de seus colaboradores como também no aumento de eficiência da produtividade. Para isso algumas empresas investem em alta tecnologia como Centros de Realidades Virtuais para simular e prever atividades futuras e desenvolver novos produtos. Esta ferramenta utilizada pelas indústrias busca antecipar a melhor solução para os postos de trabalho tornando as atividades menos desgastantes e penosas como também tornando os produtos mais eficientes. Deste modo a pesquisa teve como objetivo avaliar a aplicação da realidade virtual imersiva na análise e avaliação ergonômica por meio do design participativo e assim conhecer suas potencialidades. Este estudo buscou verificar até que ponto a realidade virtual pode auxiliar os especialistas em ergonomia sem que os mesmos tenham que produzir modelos físicos. A metodologia empregada nesta pesquisa envolveu a utilização de um Centro de Realidade Virtual - CRV com o método de grupo de foco simulando atividades e captando a percepção dos sujeitos envolvidos. O experimento evidenciou grande relevância nas aplicações da realidade virtual em algumas situações como na análise de biomecânica, movimento simultâneo e percepção do usuário, porém em algumas atividades verificou-se a necessidade da construção de modelos físicos para maior interação e envolvimento do sujeito. Os testes efetuados também mostraram que a realidade virtual tornou possível a avaliação ergonômica de uma atividade que seria impossível de ser efetuada em ambiente real sem que houvesse uma grande alocação financeira. Este fato se deve pelo motivo da dimensão do produto estudado (grande proporção) e a complexidade do processo... / The ergonomics is even more present time in the development of the productive process. The companies feel that the investment in ergonomics is of utmost importance in the preservation of its collaborators health as well as in the increase of efficiency of the productivity. For this reason companies invest in high technology as Centers of Virtual Realities to simulate and to foresee future activities as well as to develop new products. This tool used by the industries searches to anticipate the best solution for the work place turning tough activities less tiring as well as making the products more efficient. In this way the research had as objective to evaluate the application of the immersed virtual reality in the analysis and ergonomic evaluation through the participatory design to know its potentialities. This study aimed verifies to what point the virtual reality can assist the specialists in ergonomics without producing physical models. The methodology used in this research involved the use of a Center of Virtual Reality - CVR with the method of group of focus simulationg some activities and catching the perception of the involved person. The experiment evidenced great relevance in the applications of the virtual reality in some situations as in the analysis of biomechanics and perception of the user, however in some activities it was verified the necessity of the construction of physical models for bigger interaction and involvement of the participants. The tests had also shown that the virtual reality became the ergonomic evaluation of an activity possible which would be impossible to be done in real environment without the necessity on financial allocation. This fact is due to the reason of the dimension of the studied product (great ratio) and the complexity of the process. The tool (Virtual Reality) also provided to try the involvement of the team through participatory design ... (Complete abstract click electronic access below)

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Submitted by Almir Azevedo (barbio1313@gmail.com) on 2018-08-14T14:31:33Z No. of bitstreams: 1 EUGENIO RANGEL MARINS D.pdf: 3587992 bytes, checksum: 347c37f89816e9401a975c1ecc78fab3 (MD5) / Made available in DSpace on 2018-08-14T14:31:33Z (GMT). No. of bitstreams: 1 EUGENIO RANGEL MARINS D.pdf: 3587992 bytes, checksum: 347c37f89816e9401a975c1ecc78fab3 (MD5) Previous issue date: 2018-06 / Embora o Brasil não seja o típico alvo de ações terroristas, esse perigo não deve ser ignorado ou subestimado. Na nova ordem mundial, aqueles que se sentem ameaçados ou prejudicados algumas vezes abandonam as vias diplomáticas e recorrem a métodos não convencionais de resposta, que, por sua vez, podem resultar em atos de terrorismo. Com o aumento no número desse tipo de atentado em anos recentes, a importância da guarda e controle de materiais que possam ser usados em atos de terrorismo tomou uma dimensão mais relevante na atenção de governos, instituições e órgãos competentes pela salvaguarda de tais materiais. Por seu amplo potencial de causar prejuízos humanos, financeiros e morais, materiais nucleares e radioativos são o foco de programas e estratégias de salvaguardas com dimensões que vão desde as instituições individuais até o âmbito de organizações internacionais. O objetivo deste trabalho é investigar a integração das técnicas de Realidade Virtual ao planejamento das estratégias de proteção física a instalações nucleares e do treinamento da equipe que irá executá-las, de forma a evitar atos criminosos envolvendo materiais radioativos. Os resultados deste trabalho indicam que modelos virtuais de instalações nucleares podem auxiliar na elaboração e revisão das estratégias de proteção física e no treinamento das ações coordenadas das equipes de proteção física em emergências. / Although Brazil is not a typical target of terrorist action, this danger should not be ignored or underestimated. In the new world order, those who feel threatened or harmed sometimes abandon diplomatic ways and resort to unconventional methods of response, which can result in acts of terrorism. With the increasing number of such attacks in recent years, the importance of the custody and control of materials that can be used in acts of terrorism have taken a larger dimension in the attention of governments and institutions to the proper safeguard of these materials. Due to its great potential to cause human, financial and moral damages, nuclear and radioactive materials are the focus of safeguard programs and strategies, with dimensions ranging from individual institutions to the framework of international organizations. The objective of this work is to investigate the integration of Virtual Reality techniques in the planning of security strategies for nuclear installations and the training of the team that will execute them, in order to avoid criminal acts involving radioactive materials. The results of this work indicate that virtual models of nuclear installations can assist in the elaboration and revision of the security strategies and in the training of the coordinated actions of the physical protection teams in emergencies.

With the huge rise in popularity for Virtual Reality headsets, the market has become a bit of a wild-west situation where the technology is being explored for strengths, weaknesses and possible uses. Though, VR headsets have also opened up the possibility to explore and use alternate input and output devices to give a more realistic feeling. The boom has also opened up the doors for the use of Virtual Reality within education. The purpose of this paper is to investigate whether there is a difference between people that play video games and people who don’t when using Virtual Reality. This thesis was tested in a five minute experience using Unreal Engine 4. As hardware, the HTC Vive and Leap Motion were used. / Med den stora ökningen i popularitet för Virtual Reality headsets har marknaden blivit lite av en vilda västern situation där teknologin utforskas för att hitta styrkor, svagheter och användningsområden. VR headsets har också öppnat upp för möjligheten att utforska och använda alternativa gränssnitt för att ge en mer realistisk känsla. Ökningen har också öppnat dörrar för att använda Virtual Reality inom utbildning. Målet med denna uppsats är att utreda om det finns en skillnad mellan folk som spelar datorspel och folk som inte gör det när Virtual Reality används. Denna undersökning gjordes i en fem minuters lång upplevelse skapad med hjälp av Unreal Engine 4. Som hårdvara användes HTC Vive och Leap Motion.

This thesis investigates the development of a low cost, component based facial virtual conferencing system. The design is decomposed into an encoding phase and a decoding phase, which communicate with each other via a network connection. The encoding phase is composed of three components: model acquisition (which handles avatar generation), pose estimation and expression analysis. Audio is not considered part of the encoding and decoding process, and as such is not evaluated. The model acquisition component is implemented using a visual hull reconstruction algorithm that is able to reconstruct real-world objects using only sets of images of the object as input. The object to be reconstructed is assumed to lie in a bounding volume of voxels. The reconstruction process involves the following stages: - Space carving for basic shape extraction; - Isosurface extraction to remove voxels not part of the surface of the reconstruction; - Mesh connection to generate a closed, connected polyhedral mesh; - Texture generation. Texturing is achieved by Gouraud shading the reconstruction with a vertex colour map; - Mesh decimation to simplify the object. The original algorithm has complexity O(n), but suffers from an inability to reconstruct concave surfaces that do not form part of the visual hull of the object. A novel extension to this algorithm based on Normalised Cross Correlation (NCC) is proposed to overcome this problem. An extension to speed up traditional NCC evaluations is proposed which reduces the NCC search space from a 2D search problem down to a single evaluation. Pose estimation and expression analysis are performed by tracking six fiducial points on the face of a subject. A tracking algorithm is developed that uses Normalised Cross Correlation to facilitate robust tracking that is invariant to changing lighting conditions, rotations and scaling. Pose estimation involves the recovery of the head position and orientation through the tracking of the triangle formed by the subject's eyebrows and nose tip. A rule-based evaluation of points that are tracked around the subject's mouth forms the basis of the expression analysis. A user assisted feedback loop and caching mechanism is used to overcome tracking errors due to fast motion or occlusions. The NCC tracker is shown to achieve a tracking performance of 10 fps when tracking the six fiducial points. The decoding phase is divided into 3 tasks, namely: avatar movement, expression generation and expression management. Avatar movement is implemented using the base VR system. Expression generation is facilitated using a Vertex Interpolation Deformation method. A weighting system is proposed for expression management. Its function is to gradually transform from one expression to the next. The use of the vertex interpolation method allows real-time deformations of the avatar representation, achieving 16 fps when applied to a model consisting of 7500 vertices. An Expression Parameter Lookup Table (EPLT) facilitates an independent mapping between the two phases. It defines a list of generic expressions that are known to the system and associates an Expression ID with each one. For each generic expression, it relates the expression analysis rules for any subject with the expression generation parameters for any avatar model. The result is that facial expression replication between any subject and avatar combination can be performed by transferring only the Expression ID from the encoder application to the decoder application. The ideas developed in the thesis are demonstrated in an implementation using the CoRgi Virtual Reality system. It is shown that the virtual-conferencing application based on this design requires only a bandwidth of 2 Kbps. / Adobe Acrobat Pro 9.4.6 / Adobe Acrobat 9.46 Paper Capture Plug-in

This thesis presents a Virtual Sculpting system, which addresses the problem of Free-Form Solid Modelling. The disparate elements of a Polygon-Mesh representation, a Directly Manipulated Free-Form Deformation sculpting tool, and a Virtual Environment are drawn into a cohesive whole under the mantle of a clay-sculpting metaphor. This enables a user to mould and manipulate a synthetic solid interactively as if it were composed of malleable clay. The focus of this study is on the interactivity, intuitivity and versatility of such a system. To this end, a range of improvements is investigated which significantly enhances the efficiency and correctness of Directly Manipulated Free-Form Deformation, both separately and as a seamless component of the Virtual Sculpting system.

The purpose of the study was to examine the efficacy of virtual reality exposure therapy (VRET) to treat driving phobia using a multiple baseline across-subjects design. The sequence of events included a pre-treatment assessment, a baseline phase, 8 weekly VRET sessions using a standardized treatment protocol, a post-treatment assessment, and 1- and 3-month follow-up assessments. A sample of seven treatment seeking adults with a primary diagnosis of specific phobia (driving) was recruited. Five completed the treatment and follow-up phases. One individual withdrew after the pre-treatment assessment, and the other, after the first treatment session. It was hypothesized that VRET would reduce driving anxiety and avoidance symptoms between pre- and post-treatment assessments using several outcome measures. Visual and statistical analysis methods were used to assess treatment outcome. Three participants showed clear improvement in driving anxiety and avoidance symptoms between pre- and post-treatment assessments. There was a marginal improvement in these symptoms for one participant. The remaining participant showed very little improvement, and some outcome measures revealed slight deterioration in some of her symptoms. There was negligible change in actual driving frequency in any participant. Some gains were lost at the 1- and 3-month follow-up assessments, but symptoms remained far below pre-treatment results. Possibilities for future research and practice implications are discussed. / Education, Faculty of / Educational and Counselling Psychology, and Special Education (ECPS), Department of / Graduate

This thesis explores the production process of developing a virtual reality experience with an emphasis on digital humanities and the methods of adapting real-world events, narratives, and media coverage into an interactive, location based VR experience. The thesis contextualizes the production of an accompanying media project, which is informed by the history of U.S migration and the media’s impact on the opinion of Americans. Through the observation of production methods, this paper summarizes the process of creating a VR experience that expands the established production pipeline to more fluidly produce immersive interactive content. Using Homebound: The Interactive Immigrant Experience, a collaborative VR project as a prototype for these methods, we were able to integrate and develop a media production pipeline that uses off the shelf hardware in unison with Unreal Engine 4 to produce a prototype VR experience that follows the narrative on a Latin American Immigrant. / Includes bibliography. / Thesis (M.F.A.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

The problem of immigration has been around since the dawn of man because humans cannot just stay in one place, especially if that place is not suitable for their lives and their families. It is a reasonable expectation of the human condition to want to feel free and safe because we do not live in a utopian society. There are social injustices, wars, and atrocities that threaten the most basic of human needs and freedoms in many countries across the globe. Homebound, the virtual reality experience, which was developed in Unreal, aims to make sense of this crisis and shed light on the lives affected by this social ill. By using rich environments, virtual production and motion capture, to construct a place that captures the realism of the illegal immigration narrative, this manuscript will show how behavioral and gameplay psychology, when paired with environmental storytelling, can be utilized to craft impactful and empathetic, immersive stories and edutainment experiences for the player. / Includes bibliography. / Thesis (M.F.A.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection