Simplificação de malhas visando representações em multirresolução

The representation of real objects in virtual environments has applications in many areas, such as cartography, mixed reality and reverse engineering. The generation of these objects can be performed through two ways: manually, with CAD (Computer Aided Design) tools, or automatically, by means of surface reconstruction techniques. The simpler the 3D model, the easier it is to process and store it. However, this methods can generate very detailed virtual elements, that can result in some problems when processing the resulting mesh, because it has a lot of edges and polygons that have to be checked at visualization. Considering this context, it can be applied simplification algorithms to eliminate polygons from resulting mesh, without change its topology, generating a lighter mesh with less irrelevant details. The project aimed the study, implementation and comparative tests of simplification algorithms applied to meshes generated through a reconstruction pipeline based on point clouds. This work proposes the realization of the simplification step, like a complement to the pipeline developed by (ONO et al., 2012), that developed reconstruction through cloud points obtained by Microsoft Kinect, and then using Poisson algorithm

Utilização do protocolo anycast em ambientes virtuais distribuídos visando à escalabilidade do sistema

Distributed Virtual Environments (DVE) allow multiple users interact with a virtual world by sharing, manipulating objects. Each user has his/her own vision of this world and every changes of state of the environment are distributed among other users. Due to technological constraints, most systems for distributed virtual environments support a limited number of users. The major limitation for development of DVE scale are imposed by the communication system. As the number of users grows, the amount of bandwidth required to exchange information in real time among stations to upgrade the environment and keep it in a consistent state for all connected users. Based on this situation is proposed a framework that uses the protocol anycast in the application layer that provides a load balancing among servers in the region and aims at reducing the latency of message delivery between participants selecting the DVE server best suited for the region participant to connect to the environment

Um método para reconstrução de superfícies baseado em nuvem de pontos visando representações em multirresolução

The representation of real objects in virtual environments has applications in many areas, such as cartography, mixed reality and reverse engineering. The generation of these objects can be performed in two ways: manually, with CAD (Computer Aided Design) tools, or automatically, by means of surface reconstruction techniques. The simpler the 3D model, the easier it is to process and store it. Multiresolution reconstruction methods can generate polygonal meshes in different levels of detail and, to improve the response time of a computer program, distant objects can be represented with few details, while more detailed models are used in closer objects. This work presents a new approach to multiresolution surface reconstruction, particularly interesting to noisy and low definition data, for example, point clouds captured with Kinect sensor

Formação Reflexiva do Professor em Contextos Virtuais: A Experiência do Projeto Teletandem Brasil

This article chiefly aims at discussing issues concerning reflective teacher education for and in virtual environments for language learning. Given the need for research on reflective practice in new virtual environments, we present the experience of pedagogical supervision through mediation in the virtual context for collaborative learning in teletandem. Some research results in this context, such as in Salomão (2008), Kfouri-Kaneoya (2008), Cândido (2010) and Silva (2010), show how favorable and conducive to the development of reflective pre-service teacher education it seems to be, as it emphasizes the co-construction of knowledge in a dynamic relationship between theory and practice.

A comunicação em fóruns de um curso a distância de formação de professores para uso de TDICS: análise da presença de ensino

The importance of the inclusion of digital technology in the classroom has already been pointed out by numerous authors in the educational field and some of them herald that it is through this inclusion that we can achieve transformations in school settings. Based on this assumption, this paper aims to present a distance learning course offered to in service and preservice teachers, focused on the use of technology in foreign language classroom primarily focusing on the role of teacher educators in mediating discussions. For this we sought theoretical support in studies which deal with distance courses (KENSKI, 2008), about virtual environments (ARAÚJO and MARQUESI, 2008), online discussion forums and investigation community and teaching presence (GARRISON, ANDERSON and ARCHER, 2000). Based on the previous theories presented, teacher educator’s messages were analyzed during a distance course offered to teachers in continuing and initial training, identifying marks of teaching presence and pointing to appropriate mediations and/or possible gaps. The results indicate that the teacher must be even more aware of the types of feedback that are provided and of the teaching presence mentioned by Garrison and colleagues (2000, 2001).

O professor que ensina matemática formado em ambientes virtuais de aprendizagem à distância

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Representatividade das redes sociais no processo educacional: potencialidades dos grupos virtuais como ferramentas de ensino-aprendizagem no Ensino Médio

One tool that has been in evidence, especially among young people, is Facebook. It can be classified as a synchronous communication tool that allows communities of people with similar interests to discuss and exchange experiences in real time, promoting the sharing of information and the creation of collective knowledge, even if they being in different parts of the globe. In this paper we show that Facebook can be used as an educational tool to aid the work done in the classroom and the impact of creating closed groups in online social networking for educational purposes. The survey was conducted with a group of students at a private school in Bauru/SP. We investigated the interaction profile of students with a closed group created on Facebook and through a questionnaire analyzed whether students use virtual environments for personal or educational. The survey reveals students perceptions about relevant aspects and the potential use of this tool as teaching-learning strategy

O ofuscamento da infância no brilho das telas: relações entre teoria crítica, educação e sociedade

Pós-graduação em Educação Escolar - FCLAR

A multiprojeção de ambientes virtuais gerados por motores de jogo: o histórico e o design de uma solução genérica aplicado no motor de jogo Unity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Using virtual worlds in distance learning environments

This paper presents two tools developed to facilitate the use and automate the process of using Virtual Worlds for educational purposes. The first tool has been developed to automatically create the classroom space, usually called region in the virtual world, which means, a region in the virtual world used to develop educational activities between professors, students and interactive objects. The second tool helps the process of creating 3D interactive objects in a virtual world. With these tools educators will be able to produce 3D interactive learning objects and use them in virtual classrooms improving the quality and appeal, for students, of their classes. © 2011 IEEE.

Nuclear-follower foraging associations among Characiformes fishes and Potamotrygonidae rays in clean waters environments of Teles Pires and Xingu rivers basins, Midwest Brazil

Por meio de observações sub e supra-aquáticas foram registradas associações alimentares do tipo nuclear-seguidor entre três espécies de peixes characiformes - Chalceus epakros, Hemiodus semitaeniatus e Hemiodus unimaculatus - e uma espécie de raia de água doce - Potamotrygon orbignyi - nas bacias dos rios Teles Pires e Xingu, no Centro-Oeste do Brasil. Os peixes teleósteos foram observados seguindo as raias quando estas revolviam o substrato à procura de invertebrados, formando discretas nuvens de sedimento. Essas situações atraíram os peixes que se aproximaram das raias para se alimentar de pequenas presas e outros tipos de alimentos expostos desta forma. Esse é um típico exemplo de relação comensal onde um participante é beneficiado enquanto o outro não é prejudicado e representa o segundo registro na literatura de associação alimentar do tipo nuclear-seguidor entre raias potamotrigonídeas e peixes teleósteos, demonstrando o potencial de estudos naturalísticos para a descoberta de novas interações envolvendo espécies de peixes de água doce.

The generation of scenes in mixed reality environments using the chromakey technique

A classic problem in the development of Mixed Reality systems is the registration. The correct alignment between virtual objects and the real elements is extremely important for the coherent composition of the resultant scene. Considering this context, this paper describes an approach for the composition of scenes in Mixed Reality environments using the chromakey technique for the extraction of real objects. After that, the scene is mounted in a coherent way related to the depth in OpenGL framebuffer for posterior rendering. ©2007 IEEE.

Virtual simulator for mobile robots navigation systems

This paper presents the virtual environment implementation for project simulation and conception of supervision and control systems for mobile robots, that are capable to operate and adapting in different environments and conditions. This virtual system has as purpose to facilitate the development of embedded architecture systems, emphasizing the implementation of tools that allow the simulation of the kinematic conditions, dynamic and control, with real time monitoring of all important system points. For this, an open control architecture is proposal, integrating the two main techniques of robotic control implementation in the hardware level: systems microprocessors and reconfigurable hardware devices. The implemented simulator system is composed of a trajectory generating module, a kinematic and dynamic simulator module and of a analysis module of results and errors. All the kinematic and dynamic results shown during the simulation can be evaluated and visualized in graphs and tables formats, in the results analysis module, allowing an improvement in the system, minimizing the errors with the necessary adjustments optimization. For controller implementation in the embedded system, it uses the rapid prototyping, that is the technology that allows, in set with the virtual simulation environment, the development of a controller project for mobile robots. The validation and tests had been accomplish with nonholonomics mobile robots models with diferencial transmission. © 2008 IEEE.

Treino prévio reduz o tempo de execução de tarefas visuo-espaciais em ambiente virtual

Objective. To evaluate the influence of previous adaptation to different computational environments in visuo-spacial tasks performance of healthy individuals. Method. Healthy volunteers (n = 30), 15 male, mean age 25.3 ± 3.3 years, were divided in three groups: the first group, considered control, was not adapted to the proposed environments; the second group was adapted to a closed environment (stable and expected), and the third group was adapted to an open environment A (unexpected). The proposed task was to go through two open environments B and C (maze). The dependent variables Time and Error were considered for the analysis. Results. It was observed that during the adaptation phase, in the Time variable, the groups presented a progressive improvement in the performance to each task (p = 0.0036). The group adapted in the A open environment, showed a tendency to be faster in the execution of B and C open environments tasks, than the group adapted in the closed environment (p = 0.068). Conclusion. The study suggests that subjects adapted to visuo-spacial tasks execution involving unknown and no guided situations, present a tendency to a better time performance in these tasks when compared to subjects adapted in fixed and guided situations.

Mutual occlusion between real and virtual elements in Augmented Reality based on fiducial markers

Augmented Reality (AR) systems which use optical tracking with fiducial marker for registration have had an important role in popularizing this technology, since only a personal computer with a conventional webcam is required. However, in most these applications, the virtual elements are shown only in the foreground a real element does not occlude a virtual one. The method presented enables AR environments based on fiducial markers to support mutual occlusion between a real element and many virtual ones, according to the elements position (depth) in the environment. © 2012 IEEE.