Os métodos de controle de movimento em animação baseados em Física, e utilizados em Computação Gráfica, tem como objetivo simular o comportamento de objetos de acordo com as leis físicas que governam o mundo virtual adotado. Este trabalho utiliza a dinâmica de corpos rígidos como método de controle de movimento em animação por computador aplicada a movimentos e colisões de corpos rígidos não-articulados. O trabalho também apresenta uma metodologia para projeto e implementação de simulações gráficas com o objetivo de estabelecer relações entre modos de interação e os mecanismos de abstração necessários em ambientes de simulação. A principal vantagem da utilização da Mecânica newtoniana esta no fato de que ela garante o realismo dos movimentos e colisões. Associados a cada objeto devem estar os seguintes atributos físicos: centro de massa, massa total, momento de inércia e, eventualmente, a elasticidade do material. A partir de um estado inicial (velocidade linear, posição, velocidade angular e orientação) e de estímulos iniciais sobre os objetos (forças e torques), o sistema determina a evolução do estado dinâmico inicial ao longo de um dado intervalo de tempo. Para produzir o movimento dos corpos, são resolvidos sistemas de equações diferenciais de primeira ordem utilizando métodos numéricos. O tratamento de colisões de corpos rígidos envolve a detecção da colisão e contato entre objetos e a determinação das forças de contato entre os mesmos. A estratégia utilizada para a colisão considera que num determinado instante de tempo existe apenas um ponto de contato entre dois objetos. As superfícies dos objetos são representadas por uma grade de pontos conectados para formar polígonos. Existem dois tipos de estratégias para se detectar o ponto de contato entre dois objetos: o ponto de contato resultante da intersecção do vértice das arestas de um objeto com a face poligonal de outro objeto e o resultante da intersecção da aresta de um objeto com a face poligonal de um outro objeto. A análise de impacto, para resolver a dinâmica, utiliza um método analítico que preserva os momentos linear e angular durante a colisão e resulta em novas velocidades linear e angular para cada corpo rígido. Este tratamento de colisões permite ao sistema de animação realizar, em tempo de simulação, um controle automático da restrição de que dois corpos rígidos, ao colidirem, não podem se interpenetrar. Tal tratamento automático, em geral, não realizado pelos sistemas de animação por computador atualmente existentes. O trabalho apresenta o protótipo desenvolvido para validar as soluções dadas aos problemas de determinação do movimento e detecção de colisões, assim como sua aplicação na produção de suas seqüência animadas. São comentadas, também, as extensões do presente trabalho, decorrentes da abordagem dada ao problema da simulação do comportamento fundamental de corpos rígidos num dado mundo virtual a qual permite a incorporação de outras características aos objetos: elasticidade, para modelagem de deformações, e articulações, para produção de movimentos articulados com diferentes graus de liberdade. / The goal of the motion control methods used in Computer Graphics for physically based animation is to simulate the behavior of objects according to physical laws that govern a certain virtual world. This work uses rigid body dynamics as a motion control method for animation applied to motions and collisions of non-articulated rigid bodies. In addition, the work presents a methodology for the design and implementation of graphical simulation systems with the aim of providing relationships among interaction modes and abstraction mechanisms for a variety of applications. The principal advantage in using Newtonian Mechanics is that it keeps the realism of motions and collisions. Physical attributes must be associated with objects: center of mass, mass, moment of inertia, and sometimes, elasticity of the materials. Given an initial state (linear velocity, position, angular velocity, and orientation) and initial stimuli applied to the objects (forces and torques), the system determines the evolution of the dynamic state along a determinate time interval. The motion description is obtained using numerical solutions of sets of first order differential equations. The treatment of collisions of rigid bodies involves detecting collision and contact between objects and determining the contact forces present between contacting objects. The strategy used to treat collisions takes into account that there is just one contact point between two objects. The surfaces of objects are represented by a grid of connecting points forming polygons. There are two kinds of strategies to detect the contact point between two objects: the contact point resulting of intersecting the vertices of the edges of an object with the polygonal face of another one and that resulting of intersecting the edges of an object with the polygonal face of another one. The analysis of impact, to resolve the dynamic, uses an analytical method that preserves the linear and angular moments during the collision, finding a new linear and angular velocity for each rigid body. This treatment of collision allows the animation system to provide, at simulation time, an automatic control of the restriction that there is no interpenetration between two rigid bodies when they colide. This automatic treatment in general is not provided by existing computer animation systems. The work presents the prototype developed for validating the solutions given to the problems of motion control and collisions treatment, as well as its application in the production of animated sequences. The text ends with comments on extension of the present work from the approach given to the problem of simulating the behavior of objects in a certain virtual world allowing the incorporation of other characteristics to the objects: elasticity, to model deformations, and articulations, for the production of articulated movements with different degrees of freedom.

Os métodos de controle de movimento em animação baseados em Física, e utilizados em Computação Gráfica, tem como objetivo simular o comportamento de objetos de acordo com as leis físicas que governam o mundo virtual adotado. Este trabalho utiliza a dinâmica de corpos rígidos como método de controle de movimento em animação por computador aplicada a movimentos e colisões de corpos rígidos não-articulados. O trabalho também apresenta uma metodologia para projeto e implementação de simulações gráficas com o objetivo de estabelecer relações entre modos de interação e os mecanismos de abstração necessários em ambientes de simulação. A principal vantagem da utilização da Mecânica newtoniana esta no fato de que ela garante o realismo dos movimentos e colisões. Associados a cada objeto devem estar os seguintes atributos físicos: centro de massa, massa total, momento de inércia e, eventualmente, a elasticidade do material. A partir de um estado inicial (velocidade linear, posição, velocidade angular e orientação) e de estímulos iniciais sobre os objetos (forças e torques), o sistema determina a evolução do estado dinâmico inicial ao longo de um dado intervalo de tempo. Para produzir o movimento dos corpos, são resolvidos sistemas de equações diferenciais de primeira ordem utilizando métodos numéricos. O tratamento de colisões de corpos rígidos envolve a detecção da colisão e contato entre objetos e a determinação das forças de contato entre os mesmos. A estratégia utilizada para a colisão considera que num determinado instante de tempo existe apenas um ponto de contato entre dois objetos. As superfícies dos objetos são representadas por uma grade de pontos conectados para formar polígonos. Existem dois tipos de estratégias para se detectar o ponto de contato entre dois objetos: o ponto de contato resultante da intersecção do vértice das arestas de um objeto com a face poligonal de outro objeto e o resultante da intersecção da aresta de um objeto com a face poligonal de um outro objeto. A análise de impacto, para resolver a dinâmica, utiliza um método analítico que preserva os momentos linear e angular durante a colisão e resulta em novas velocidades linear e angular para cada corpo rígido. Este tratamento de colisões permite ao sistema de animação realizar, em tempo de simulação, um controle automático da restrição de que dois corpos rígidos, ao colidirem, não podem se interpenetrar. Tal tratamento automático, em geral, não realizado pelos sistemas de animação por computador atualmente existentes. O trabalho apresenta o protótipo desenvolvido para validar as soluções dadas aos problemas de determinação do movimento e detecção de colisões, assim como sua aplicação na produção de suas seqüência animadas. São comentadas, também, as extensões do presente trabalho, decorrentes da abordagem dada ao problema da simulação do comportamento fundamental de corpos rígidos num dado mundo virtual a qual permite a incorporação de outras características aos objetos: elasticidade, para modelagem de deformações, e articulações, para produção de movimentos articulados com diferentes graus de liberdade. / The goal of the motion control methods used in Computer Graphics for physically based animation is to simulate the behavior of objects according to physical laws that govern a certain virtual world. This work uses rigid body dynamics as a motion control method for animation applied to motions and collisions of non-articulated rigid bodies. In addition, the work presents a methodology for the design and implementation of graphical simulation systems with the aim of providing relationships among interaction modes and abstraction mechanisms for a variety of applications. The principal advantage in using Newtonian Mechanics is that it keeps the realism of motions and collisions. Physical attributes must be associated with objects: center of mass, mass, moment of inertia, and sometimes, elasticity of the materials. Given an initial state (linear velocity, position, angular velocity, and orientation) and initial stimuli applied to the objects (forces and torques), the system determines the evolution of the dynamic state along a determinate time interval. The motion description is obtained using numerical solutions of sets of first order differential equations. The treatment of collisions of rigid bodies involves detecting collision and contact between objects and determining the contact forces present between contacting objects. The strategy used to treat collisions takes into account that there is just one contact point between two objects. The surfaces of objects are represented by a grid of connecting points forming polygons. There are two kinds of strategies to detect the contact point between two objects: the contact point resulting of intersecting the vertices of the edges of an object with the polygonal face of another one and that resulting of intersecting the edges of an object with the polygonal face of another one. The analysis of impact, to resolve the dynamic, uses an analytical method that preserves the linear and angular moments during the collision, finding a new linear and angular velocity for each rigid body. This treatment of collision allows the animation system to provide, at simulation time, an automatic control of the restriction that there is no interpenetration between two rigid bodies when they colide. This automatic treatment in general is not provided by existing computer animation systems. The work presents the prototype developed for validating the solutions given to the problems of motion control and collisions treatment, as well as its application in the production of animated sequences. The text ends with comments on extension of the present work from the approach given to the problem of simulating the behavior of objects in a certain virtual world allowing the incorporation of other characteristics to the objects: elasticity, to model deformations, and articulations, for the production of articulated movements with different degrees of freedom.

La plupart des simulations interactives ont besoin d'un modèle de détection de collisions. Cette détection nécessite d'une part d'effectuer des requêtes de proximité entre les entités concernées et d'autre part de calculer un comportement à appliquer. Afin d'effectuer ces requêtes, les entités présentes dans une scène sont soit hiérarchisées dans un arbre ou dans un graphe de proximité, soit plongées dans une grille d'enregistrement. Nous présentons un nouveau modèle de détection de collisions s'appuyant sur deux piliers : une représentation de l'environnement par des cartes combinatoires multirésolutions et un suivi en temps réel de particules plongées dans ces cartes. Ce modèle nous permet de représenter des environnements complexes tout en suivant en temps réel les entités évoluant dans cet environnement. Nous présentons des outils d'enregistrement et de maintien de l'enregistrement de particules, d'arêtes et de surfaces dans des cartes combinatoires volumiques multirésolutions. / Most interactive simulations need a collision detection system. First, this system requires the querying of the proximity between the objects and then the computing of the behaviour to be applied. In order to perform these queries, the objects present in a scene are either classified in a tree, in a proximity graph, or embedded inside a registration grid.Our work present a new collision detection model based on two main concepts: representing the environment with a combinatorial multiresolution map, and tracking in real-time particles embedded inside this map. This model allows us to simulate complex environments while following in real-time the entities that are evolving within it.We present our framework used to register and update the registration of particles, edges and surfaces in volumetric combinatorial multiresolution maps. Results have been validated first in 2D with a crowd simulation application and then in 3D, in the medical field, with a percutaneous surgery simulation.

This work describes path finding among obstacles in 3D space using probabilistic algorithms. Users can create scene in application GUI - define start object, obstacles, goal position and run probabilistic algorithm. The finding path is visualized. The work describes probabilistic algorithm, collision detection and the basics of 3D graphics and shows design and implementation of an application created.

The thesis deals with the changes of a cable robot to a manipulator. The mechanical changes are mostly about adding an active part to a moving platform with the ability to transfer objects and the effort to exchange the silicon cables for metal ones. The main part of the thesis is the proposed design and implementation of the algorithm for detection of a possible collision of the cable robot with an object in its working space.

Modeling molecular structures is critical for understanding the principles that govern the behavior of molecules and for facilitating the exploration of potential pharmaceutical drugs and nanoscale designs. Biological molecules are flexible bodies that can adopt many different shapes (or conformations) until they reach a stable molecular state that is usually described by the minimum internal energy. A major challenge in modeling flexible molecules is the exponential explosion in computational complexity as the molecular size increases and many degrees of freedom are considered to represent the molecules' flexibility. This research work proposes a novel generic computational geometric approach called enhanced BioGeoFilter (g.eBGF) that geometrically interprets inter-atomic interactions to impose geometric constraints during molecular conformational search to reduce the time for identifying chemically-feasible conformations. Two new methods called Kinematics-Based Differential Evolution (kDE) and Biological Differential Evolution (BioDE) are also introduced to direct the molecular conformational search towards low energy (stable) conformations. The proposed kDE method kinematically describes a molecule's deformation mechanism while it uses differential evolution to minimize the inta-molecular energy. On the other hand, the proposed BioDE utilizes our developed g.eBGF data structure as a surrogate approximation model to reduce the number of exact evaluations and to speed the molecular conformational search. This research work will be extremely useful in enabling the modeling of flexible molecules and in facilitating the exploration of nanoscale designs through the virtual assembly of molecules. Our research work can also be used in areas such as molecular docking, protein folding, and nanoscale computer-aided design where rapid collision detection scheme for highly deformable objects is essential.

Detta examensarbete har undersökt möjligheterna att kombinera multi-master databasreplikeringstekniker tillsammans med en LEMP-stack på små servrar för att öka tillgängligheten av e-Learning tjänster i avlägsna områden i Tanzania. Målet var att utvärdera kombinationen av Symmetric DS för databas synkronisering och kollitionsdetektering och resolution med e-Learning systemet Moodle. Detta gjordes genom att en litteraturstudie genomfördes och uppföjdes av implementation och konfiguration på plats i Tanzania. Slutsatsen var att de för projektet utvalda teknologierna, mjukvaran och hårdvaran var konfigurerbar i teorin men ohållbart kostsam att implementera i praktiken. / This research has investigated the possibility to combine multi-master database replication technologies together with a LEMP-stack on tiny servers to increase the availability of e-Learning services in remote areas in Tanzania. The aim was to evaluate the combination of Symmetric DS for multi master database replication and conflict detection and resolution with the e-learning system Moodle. This was done by conducting a literature study of relevant technologies followed by implementation and configuration at the location. The conclusion was that the technologies, software and hardware chosen for the project were configurable in theory but not viable to implement and maintain in practice.

Collision detection between deforming models is a difficult problem for collision detection systems to handle. This problem is even more difficult when deformations are unconstrained, objects are in close proximity to one another, and when the entity count is high. We propose a method to perform collision detection between multiple deforming objects with unconstrained deformations that will give good results in close proximities. Currently no systems exist that achieve good performance on both unconstrained triangle level deformations and deformations that preserve edge connectivity. We propose a new system built as a combination of Graphics Processing Unit (GPU) based culling and Axis Aligned Bounding Box (AABB) based culling. Techniques for performing hierarchy-less GPU-based culling are given. We then discuss how and when to switch between GPU-based culling and AABB based techniques.

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