Crowd simulations are attracting increasing attention from both academia and the industry field and are implemented across a vast range of applications, from scientific demonstrations to video games and films. As such, the demand for greater realism in their aesthetics and the amount of agents involved is always growing. A successful crowd simulation must simulate large numbers of pedestrians' behaviours as realistically as possible in real-time. The thesis looks at two important aspects of crowd simulation and real-time animation. First, this thesis introduces a new data structure called Extended Oriented Bounding Box (EOBB) and related methods for fast collision detection and obstacle avoidance in the simulation of crowd motion in virtual environments. The EOBB is extended to contain a region whose size is defined based on the instantaneous velocity vector, thus allowing a bounding volume representation of both geometry and motion. Such a representation is also found to be highly effective in motion planning using the location of vertices of bounding boxes in the immediate neighbourhood of the current crowd member. Second, we present a detailed analysis of the effectiveness of spatial subdivision data structures, specifically for large-scale crowd simulation. For large-scale crowd simulation, computational time for collision detection is huge, and many studies use spatial partitioning data structure to reduce the computational time, depicting their strengths and weaknesses, but few compare multiple methods in an effort to present the best solution. This thesis attempts to address this by implementing and comparing four popular spatial partitioning data structures with the EOBB.

[pt] A restituição de modelos tridimensionais complexos de engenharia tem sido um desafio para a computação gráfica desde seus primórdios, pois modelos detalhados são freqüentemente compostos de milhões de polígonos, enquanto as estações gráficas atuais são capazes de exibir, em taxas interativas, apenas algo da ordem de dezenas ou centenas de milhares de polígonos. Uma das formas de melhorar o desempenho de visualizadores de modelos tridimensionais é reduzir o número de polígonos passados para a cadeia de restituição, eliminando grandes grupos de polígonos determinados como não visíveis por estarem fora do volume de visão ou escondidos por outros polígonos. Neste trabalho, realizamos um estudo do uso de volumes envolventes para determinar os conjuntos de polígonos que são potencialmente visíveis, propomos uma forma de estruturar esses polígonos numa hierarquia de forma a diminuir os cálculos necessários para esse fim e compilamos uma série de resultados que permitem nortear o uso de volumes envolventes e a estruturação de modelos. / [en] Rendering complex three-dimensional Engineering models has been a challenge for Computer Graphics ever since its origin, as detailed models are often composed of millions of polygons while current graphic stations are able to display, at interactive rates, only dozens or hundreds of thousands of polygons. A way to increase the performance of viewers of three-dimensional models is to reduce the number of polygons passed to the rendering pipeline by eliminating large groups of polygons classified as non-visible for being out of the viewing frustum or hidden by other polygons. In this work, we study the use of bounding volumes to determine sets of polygons which are potentially visible, propose a way to structure such polygons in a hierarchy so as to restrict the necessary computations for this purpose, and compile a series of results which allow us to take some conclusions on the use of bounding volumes and model structuring.

This thesis presents several new techniques for developing safe and flexible human-robot interaction tasks where human operators cooperate with robotic manipulators. The contributions of this thesis are divided in two fields: the development of safety strategies which modify the normal behavior of the robotic manipulator when the human operator is near the robot and the development of dexterous manipulation tasks for in-hand manipulation of objects with a multi-fingered robotic hand installed at the end-effector of a robotic manipulator. / Valencian Government by the research project "Infraestructura 05/053". Spanish Ministry of Education and Science by the pre-doctoral grant AP2005-1458 and the research projects DPI2005-06222 and DPI2008-02647, which constitute the research framework of this thesis.

Práce se zabývá detekcí kolizí v 3D simulačním prostoru. V první části jsou popsány nejpoužívanější algoritmy pro detekci, stejně jako některé knihovny hotových řešení. Druhá část práce obsahuje popis testovacího softwaru vytvořeného na základě knihovny OpenGL, včetně popisu důležitých částí. V poslední části práce jsou také prezentovány výsledky testování a porovnání vybraných algoritmů na vytvořených testovacích úlohách.