Real-Time deep image rendering and order independent transparency

In computer graphics some operations can be performed in either object space or image space. Image space computation can be advantageous, especially with the high parallelism of GPUs, improving speed, accuracy and ease of implementation. For many image space techniques the information contained in regular 2D images is limiting. Recent graphics hardware features, namely atomic operations and dynamic memory location writes, now make it possible to capture and store all per-pixel fragment data from the rasterizer in a single pass in what we call a deep image. A deep image provides a state where all fragments are available and gives a more complete image based geometry representation, providing new possibilities in image based rendering techniques. This thesis investigates deep images and their growing use in real-time image space applications. A focus is new techniques for improving fundamental operation performance, including construction, storage, fast fragment sorting and sampling. A core and driving application is order-independent transparency (OIT). A number of deep image sorting improvements are presented, through which an order of magnitude performance increase is achieved, significantly advancing the ability to perform transparency rendering in real time. In the broader context of image based rendering we look at deep images as a discretized 3D geometry representation and discuss sampling techniques for raycasting and antialiasing with an implicit fragment connectivity approach. Using these ideas a more computationally complex application is investigated — image based depth of field (DoF). Deep images are used to provide partial occlusion, and in particular a form of deep image mipmapping allows a fast approximate defocus blur of up to full screen size

Caracterização do espaço poroso em rochas por esferas máximas exatas

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da ComputaçãoNeste trabalho, uma modificação ao algoritmo de esferas máximas (MB) é proposto. Essa abordagem recebe o nome de esferas máximas exatas (EMB), por utilizar os raios exatos ao invés de duas aproximações. Tal mudança, traz consequências para o resultado final, definindo de forma mais detalhada a estrutura interna do espaço poroso, gerando cinquenta por cento mais poros e gargantas. Dessa forma, a rede gerada de modo exato é comparada a rede original, em características básicas e nas simulações de escoamento monofásico, obtendo-se resultados bem correlacionados e em mesma escala de grandeza para ambas, apesar de diferentes. Muitas otimizações para paralelização e dados comprimidos são propostas e o algoritmo exato, mesmo processando mais esferas, é de duas a seis mais rápido para todos os casos de estudo.In this work a maximum balls (MB) modification is presented. This novel approach receives the name of exact maximum balls (EMB) because it uses one exact radius instead of two approximations. Therefore, there are consequences to the generated pore network which is found out to define the pore space with at least fifty porcent more detail, that is, pores and throats. That way, the exact pore network is compared with the original and it is discovered that there is a strict correlation between their results and that these are always of the same magnitude, although different. Also, a lot of optimizations to process compressed data and to allow data parallelization are shown and the EMB pore network extraction is, in every test case, consistently faster than MB. The obtained speedup was from two up to six times

MS FT-2-2 7 Orthogonal polynomials and quadrature: Theory, computation, and applications

Quadrature rules find many applications in science and engineering. Their analysis is a classical area of applied mathematics and continues to attract considerable attention. This seminar brings together speakers with expertise in a large variety of quadrature rules. It is the aim of the seminar to provide an overview of recent developments in the analysis of quadrature rules. The computation of error estimates and novel applications also are described