Dissertations / Theses: 'Ray tracing'

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Hošek, Václav. "Distributed Ray Tracing." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2008. http://www.nusl.cz/ntk/nusl-235956.

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VYSOKÉ UČENÍ TECHNICKÉ V BRNĚ Distributed Ray Tracing, also called distribution ray tracing and stochastic ray tracing, is a refinement of ray tracing that allows for the rendering of "soft" phenomena, area light, depth of field and motion blur.

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Yun, Garam. "Polarization Ray Tracing." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/202979.

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A three-by-three polarization ray tracing matrix method is developed to calculate the polarization transformations associated with ray paths through optical systems. The relationship between the three-by-three polarization ray tracing matrix P method and the Jones calculus is shown in Chapter 2. The diattenuation, polarization dependent transmittance, is calculated via a singular value decomposition of the P matrix and presented in Chapter 3. In Chapter 4 the concept of retardance is critically analyzed for ray paths through optical systems. Algorithms are presented to separate the effects of retardance from geometric transformations. The parallel transport of vectors is associated with non-polarizing propagation through an optical system. A parallel transport matrix Q establishes a proper relationship between sets of local coordinates along the ray path, a sequence of ray segments. The proper retardance is calculated by removing this geometric transformation from the three-by-three polarization ray trace matrix. Polarization aberration is wavelength and spatial dependent polarization change that occurs as wavefrontspropagate through an optical system. Diattenuation and retardance of interfaces and anisotropic elements are common sources of polarizationaberrations. Two representations of polarization aberrationusing the Jones pupil and a polarization ray tracing matrix pupil, are presentedin Chapter 5. In Chapter 6 a new class of aberration, skew aberration is defined, as a component of polarization aberration. Skew aberration is an intrinsic rotation of polarization states due to the geometric transformation of local coordinates; skew aberration occurs independent of coatings and interface polarization. Skew aberration in a radially symmetric system primarily has the form of a tilt plus circular retardance coma aberration. Skew aberration causes an undesired polarization distribution in the exit pupil. A principal retardance is often defined within (-π, + π] range. In Chapter 7 an algorithm which calculates the principal retardance, horizontal retardance component, 45° retardance component, and circular retardance component for given retarder Jones matrices is presented. A concept of retarder space is introduced to understand apparent discontinuities in phase unwrapped retardance. Dispersion properties of retarders for polychromatic light is used to phase unwrap the principal retardance. Homogeneous and inhomogeneous compound retarder systems are analyzed and examples of multi-order retardance are calculated for thick birefringent plates. Mathematical description of the polarization properties of light and incoherent addition of light is presented in Chapter 8, using a coherence matrix. A three-by-three-by-three-by-three polarization ray tracing tensor method is defined in order to ray trace incoherent light through optical systems with depolarizing surfaces. The polarization ray tracing tensor relates the incident light’s three-by-three coherence matrix to the exiting light’s three-by-three coherence matrix. This tensor method is applicable to illumination systems and polarized stray light calculations where rays at an imaging surface pixel have optical path lengths which vary over many wavelengths. In Chapter 9 3D Stokes parameters are defined by expanding the coherence matrix with Gell-Mann matrices as a basis. The definition of nine-by-nine 3D Mueller matrix is presented. The 3D Mueller matrix relates the incident 3D Stokes parameters to the exiting 3D Stokes parameters. Both the polarization ray tracing tensor and 3D Mueller matrix are defined in global coordinates. In Chapter 10 a summary of my work and future work are presented followed by a conclusion.

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Huss, Niklas. "Real Time Ray Tracing." Thesis, Linnéuniversitetet, Institutionen för datavetenskap, fysik och matematik, DFM, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-9207.

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Ray tracing has for a long time been used to create photo realistic images, but due to complex calculations done per pixel and slow hardware, the time to render a frame has been counted in hours or even days and this can be drawback if a change of a scene cannot be seen instantly. When ray tracing a frame takes less than a second to render we call it “real time ray tracing” or “interactive ray tracing” and many solutions have been developed and some involves distributing the computation to different computers interconnected in a very fast network (100 Mbit or higher). There are some drawbacks with this approach because most people do not have more than one computer and if they have, the computers are most likely not connected to each other. Since the hardware of today is fast enough to render a pretty complex image within minutes it should be possible to achieve real time ray tracing by combining many different methods that has been developed and reduce the render time. This work will examine what has to be sacrificed in image quality and complexity of static scenes, in order to achieve real time frame rate with ray tracing on a single computer. Some of the methods that will be covered in this work are frame optimizations, secondary rays optimization, hierarchies, culling, shadow caching, and sub sampling.

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Spjut, Josef Bo. "Efficient ray tracing architectures." Thesis, The University of Utah, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3727095.

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This dissertation presents computer architecture designs that are efficient for ray tracing based rendering algorithms. The primary observation is that ray tracing maps better to independent thread issue hardware designs than it does to dependent thread and data designs used in most commercial architectures. While the independent thread issue causes extra overhead in the fetch and issue parts of the pipeline, the number of computation resources required can be reduced through the sharing of less frequently used execution units. Furthermore, since all the threads run a single program on multiple data (SPMD), thread processors can share instruction and data caches. Ray tracing needs read-only access to the scene data during each frame, so caches can be optimized for reading, and traditional cache coherence protocols are unnecessary for maintaining coherent memory access. The resultant image exists as a write only frame buffer, allowing memory writes to avoid the cache entirely, preventing cache pollution and increasing the performance of smaller caches.

Commercial real-time rendering systems lean heavily on high-performance graphics processing units (GPU) that use the rasterization and z-buffer algorithms for rendering. A single pass of rasterization throws out much of the global scene information by streaming the surface data that a ray tracer keeps resident in memory. As a result, ray tracing is more naturally able to support rendering effects involving global information, such as shadows, reflections, refractions and camera lens effects. Rasterization has a time complexity of approximately O(N log(P)) where N is the number of primitive polygons and P is the number of pixels in the image. Ray tracing, in contrast, has a time complexity of O(P log(N)) making ray tracing scale better to large scenes with many primitive polygons, allowing for increased surface detail. Finally, once the number of pixels reaches its limit, ray tracing should exceed the performance of rasterization by allowing the number of objects to increase with less of a penalty on performance.

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Trendall, Chris. "Ray tracing refraction in hardware." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0016/MQ49742.pdf.

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Kukla, Michal. "Ray-tracing s knihovnou IPP." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2010. http://www.nusl.cz/ntk/nusl-237265.

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Master thesis is dealing with design and implementation of ray-tracing and path-tracing using IPP library. Theoretical part discusses current trends in acceleration of selected algorithms and also possibilities of parallelization. Design of ray-tracing and path-tracing algorithm and form of parallelization are described in proposal. This part also discusses implementation of adaptive sampling and importance sampling with Monte Carlo method to accelerate path-tracing algorithm. Next part is dealing with particular steps in implementation of selected rendering methods regarding IPP library. Implementation of network interface using Boost library is also discussed. At the end, implemented methods are subjected to performance and quality test. Final product of this thesis is server aplication capable of handling multiple connections which provides visualisation and client application which implements ray-tracing and path-tracing.

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Watson, Andre James. "Diffraction gratings in ray tracing." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p1464665.

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Thesis (M.S.)--University of California, San Diego, 2009.
Title from first page of PDF file (viewed July 7, 2009). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 66-67).

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McNeill, Michael D. J. "Ray tracing on multiprocessor systems." Thesis, University of Sussex, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357267.

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Polášek, Tomáš. "Hybridní raytracing v rozhraní DXR." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2019. http://www.nusl.cz/ntk/nusl-403161.

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The goal of this thesis is to evaluate the usability of hardware accelerated ray tracing in near-future rendering engines. Specifically, DirectX Ray Tracing API and Nvidia Turing architecture are being examined. Design and implementation of a hybrid rendering engine with support for hardware accelerated ray tracing is included and used in implementation of frequently used graphical effects -- hard and soft shadows, reflections, and Ambient Occlusion. The assessment is made in terms of difficulty of integration into a rendering engine, performance of the resulting system and suitability of implementation of chosen graphical effects. Performance parameters -- including number of rays cast per second, time to build acceleration structures and computation time on the GPU -- are tested and discussed.

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Sennersten, Charlotte. "Gameplay (3D Game Engine + Ray Tracing = Visual Attention through Eye Tracking)." Licentiate thesis, Karlskrona : School of Technoculture, Humanities and Planning, Blekinge Institute of Technology, 2008. http://www.bth.se/fou/Forskinfo.nsf/allfirst2/e0fc9eb5eccc5468c12574d400432db2?OpenDocument.

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Kroeze, Jan Cornelis Willem. "Tracing rays the past, present and future of ray tracing performance / Jan Cornelis Willem Kroeze." Thesis, North-West University, 2010. http://hdl.handle.net/10394/8525.

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The metrics used to compare the performance of various ray tracers in the literature are flawed because they are non-standard and depend on the hardware configuration of the specific system used to gather data. A different way of measuring the relative performance of ray tracing algorithms is proposed and tested across several hardware platforms using correlation co-efficient.
Thesis (M.Sc. (Computer Science) North-West University, Vaal Triangle Campus, 2011

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Löw, Joakim. "Ray Tracing Bézier Surfaces on GPU." Thesis, Linköping University, Department of Mathematics, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-5476.

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In this report, we show how to implement direct ray tracing of B´ezier surfaces on graphics processing units (GPUs), in particular bicubic rectangular Bézier surfaces and nonparametric cubic Bézier triangles. We use Newton’s method for the rectangular case and show how to use this method to find the ray-surface intersection. For Newton’s method to work we must build a spatial partitioning hierarchy around each surface patch, and in general, hierarchies are essential to speed up the process of ray tracing. We have chosen to use bounding box hierarchies and show how to implement stackless traversal of such a structure on a GPU. For the nonparametric triangular case, we show how to find the wanted intersection by simply solving a cubic polynomial. Because of the limited precision of current GPUs, we also propose a numerical approach to solve the problem, using a one-dimensional Newton search.

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Hilbert, Stefan Johannes. "Ray-Tracing through the Millennium Simulation." Diss., lmu, 2008. http://nbn-resolving.de/urn:nbn:de:bvb:19-85684.

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Kimura, Ryota, and Ryota Kimura. "Accelerated Ray Tracing for Headlamp Simulation." Thesis, The University of Arizona, 2017. http://hdl.handle.net/10150/626712.

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High speed ray tracing for a headlamp lens and advanced algorithms for ray analysis are investigated. First, the basics of ray tracing, Algorithm to search intersection points between a ray and surfaces and refraction are reviewed, including intersection search for a ray with aspheric surfaces. A spherical surface, a plane surface, and a point cloud are reviewed as objects. Snell’s law is introduced from Fermat’s principle in 2D. Then, it extended to three dimensional spaces. Second, photometry is reviewed for the post processing of ray tracing, due to the convolution effect of its area. To accelerate ray tracing, the Nvidia GPU and CUDA platform of general purpose computing is evaluated in this study. Its architecture and memory architecture is unique. In addition, Mathematica is used in this study for file IO and graphic output with unique CUDA interface. Then, the each ray tracing method is validated using a spherical lens, aspherical lens, and a headlamp lens. From the comparison, the double precision floating Nagata triangular patch method is best in accuracy. Acceleration of ray tracing using CUDA was successful having 2 times implement in 362 million rays traced, compared to commercially available ray trace packages under the same computing resources.

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Bezerianos, Anastasia. "Using projection to accelerate Ray Tracing." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ62959.pdf.

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McCanna, Anju Sharma. "Ray tracing for constructive solid modeling /." Online version of thesis, 1990. http://hdl.handle.net/1850/10579.

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Abdelsabor, Sohier Goma. "Ray tracing for computer synthesized images." Virtual Press, 1988. http://liblink.bsu.edu/uhtbin/catkey/539621.

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Ray tracing is a very powerful yet simple approach to image synthesis. It has generated some of the most realistic scenes to date. A comparative study of classical ray tracing, ray tracing with cones, and distributed ray tracing is made.The ray tracing techniques, classical ray tracing, ray tracing with cones, and distributed ray tracing, are explained, their differences are emphasized, and their approaches to modeling various lighting effects are explained and compared.
Department of Computer Science

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Lebovitz, Marc A. (Marc Adam) 1975. "A prediction model for ray tracing." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/80095.

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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, June 1999.
Includes bibliographical references (leaf 86).
by Marc A. Lebovitz.
M.Eng.

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Hebert, Marie-Pierre. "A multiprocessor architecture for ray tracing." Thesis, University of Sussex, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302731.

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Slovák, Radek. "Distributed Ray Tracing v rozumném čase." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2011. http://www.nusl.cz/ntk/nusl-237023.

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This thesis deals with the method of distributed ray tracing focusing on optimalization of this method. The method uses simulation of some attributes of light by distributing rays of lights and it produces high quality and partly realistic images. The price for realitic effects is the high computational complexity of the method. The thesis analysis the theory connected with these aspects. A large part describes optimalizations of this method, i.e. searching for the nearest triangle intersection using kd-trees, quasi random sampling with faster convergence, the use of SSE instruction set and fast ray - triangle intersection. These optimalizations brought a noticable speed - up. The thesis includes description of implementation of these techniques. The implementation itself emphasises the practical usability including generating some advanced animations and universal description of objects.

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Källén, Christoffer. "Acoustic Ray tracing in urban environments." Thesis, KTH, MWL Marcus Wallenberg Laboratoriet, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-211160.

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This is the report of the development of a program written in MATLAB to study the propagation of sound waves using Smit’s ray tracing algorithm. The final program is able to use the data from vectorized maps to build a three-dimensional landscape and calculate the reflections at each interception point when a ray emitted from the source hits the surface of an obstacle.Another goal is to make use of all the cores, physical and logical, a modern CPU has to offer. This is to make sure the calculations are made as fast as possible. In order to meet this criteria the MATLAB Parallel Computing Toolbox is used. This requires the program code to allow for parallel execution of the code. A routine for calculation of diffraction around the building edges is also implemented. This diffraction routine was customized to suit this particular ray tracing algorithm.
Denna rapport beskriver utvecklingen av ett program skrivet i MATLAB för strålgångsberäkningar med hjälp av Smit’s algoritm. Det färdiga programmet bygger upp ett tredimensionellt landskap med vektoriserade fastighetskartor och punktmoln från laserskannade markområden som indata för beräkning av reflektioner mot mark och byggnader. För att uppnå så korta körtider som möjligt är målsättningen att utnyttja alla tillgängliga kärnor i datorns CPU med hjälp av MATLAB Parallel Computing Toolbox. Programmet beräknar även bidrag till ljudtrycksnivån genom diffraktion runt byggnader med hjälp av en modifierad version av en tillgänglig empirisk modell för diffraktion.

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Urra, Rodrigo A. "Scalable ray tracing with multiple GPGPUs /." Online version of thesis, 2009. http://hdl.handle.net/1850/8705.

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Spackman, John Neil. "Scene decompositions for accelerated ray tracing." Thesis, University of Bath, 1989. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329580.

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Ecoublet, Philippe. "Bent-ray travel-time tomography and migration without ray tracing." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263006.

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Ullmann, Thomas. "Vertex tracing - interaktives ray tracing durch adaptiv progressives Refinement im Objektraum." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=974936189.

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Es, S. Alphan. "Accelerated Ray Tracing Using Programmable Graphics Pipelines." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609307/index.pdf.

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The graphics hardware have evolved from simple feed forward triangle rasterization devices to flexible, programmable, and powerful parallel processors. This evolution allows the researchers to use graphics processing units (GPU) for both general purpose computations and advanced graphics rendering. Sophisticated GPUs hold great opportunities for the acceleration of computationally expensive photorealistic rendering methods. Rendering of photorealistic images in real-time is a challenge. In this work, we investigate efficient ways to utilize GPUs for real-time photorealistic rendering. Specifically, we studied uniform grid based ray tracing acceleration methods and GPU friendly traversal algorithms. We show that our method is faster than or competitive to other GPU based ray tracing acceleration techniques. The proposed approach is also applicable to the fast rendering of volumetric data. Additionally, we devised GPU based solutions for real-time stereoscopic image generation which can be used in companion with GPU based ray tracers.

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Bailey, Henry Albert. "Ray tracing techniques for indirect refracted illumination." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ37789.pdf.

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Wang, Xiaomei. "Efficient ray tracing of many light sources." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq43409.pdf.

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Dreux, M. de A. "A hybrid scan-line/ray-tracing algorithm." Thesis, Brunel University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233395.

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SANTOS, PAULO IVSON NETTO. "RAY TRACING DYNAMIC SCENES ON THE GPU." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2009. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=31443@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
O objetivo deste trabalho é desenvolver uma solução completa para o traçado de raios de cenas dinâmicas utilizando a GPU. Para que este algoritmo atinja desempenho interativo, é necessário utilizar uma estrutura espacial para reduzir os testes de interseção entre raios e triângulos da cena. Observa-se que, quando há movimento na cena, é necessário atualizar esta estrutura de aceleração, seja alterando-a parcialmente ou reconstruindo-a inteiramente. Adotamos a segunda estratégia por ser capaz de tratar o caso geral de movimento não-estruturado. Como a construção da estrutura deve ser feita da forma mais eficiente possível, escolhemos utilizar uma Grade Uniforme como foco de nossa pesquisa. Suas vantagens incluem um algoritmo de construção simples e um percurso de raios eficiente. Para explorar o poder de processamento em paralelo de uma GPU, é necessário manter os dados da cena e da estrutura de aceleração dentro da placa gráfica, evitando transferências custosas de memória entre a GPU e a CPU. Propomos neste trabalho uma técnica para construir uma grade uniforme inteiramente na GPU. Usando nosso método, é possível reconstruir toda a estrutura em poucos milissegundos, enquanto mantém-se a alta qualidade da grade obtida. Além disso, propomos uma implementaçoes do algoritmo de traçado de raios de forma a aproveitar o processamento em paralelo da GPU. Nosso procedimento é implementado inteiramente dentro da placa gráfica, onde há acesso direto para os dados dos triângulos da cena, bem como as informações da grade uniforme construída. Utilizando a solução proposta, somos capazes de obter taxas de visualização interativas mesmo para cenas com movimentos não-estruturados, incluindo texturas, sombras e até mesmo reflexões.
We present a technique for ray tracing dynamic scenes using the GPU. In order to achieve interactive rendering rates, it is necessary to use a spatial structure to reduce the number of ray-triangle intersections performed. Whenever there is movement in the scene, this structure is entirely rebuilt. This way, it is possible to handle general unstructured motion. For this purpose, we have developed an algorithm for reconstructing Uniform Grids entirely inside the graphics hardware. In addition, we present ray-traversal and shading algorithms fully implemented on the GPU, including textures, shadows and reections. Combining these techniques, we demonstrate interactive ray tracing performance for dynamic scenes, even with unstructured motion and advanced shading effects.

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Perales, Remigio. "Parallel ray tracing for real time animation." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/36961.

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Santos, Eduardo Toledo. "Extensões ao algoritmo de 'RAY TRACING' parametrizado." Universidade de São Paulo, 1998. http://www.teses.usp.br/teses/disponiveis/3/3142/tde-13022004-114755/.

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Ray tracing é um algoritmo para a síntese de imagens por computador. Suas características principais são a alta qualidade das imagens que proporciona (incorporando sombras, reflexões e transparências entre outros efeitos) e, por outro lado, a grande demanda em termos de processamento. O ray tracing parametrizado é um algoritmo baseado no ray tracing, que permite a obtenção de imagens com a mesma qualidade a um custo computacional dezenas de vezes menor, porém com restrições. Estas restrições são a necessidade de geração de um arquivo de dados inicial, cujo tempo de processamento é pouco maior que o do ray tracing convencional e a não possibilidade de alteração de qualquer parâmetro geométrico da cena. Por outro lado, a geração de versões da mesma cena com mudanças nos parâmetros ópticos (cores, intensidades de luz, texturas, reflexões, transparências, etc.) é extremamente rápida. Esta tese propõe extensões ao algoritmo de ray tracing parametrizado, procurando aliviar algumas de suas restrições. Estas extensões permitem alterar alguns parâmetros geométricos como a posição das fontes de luz, parâmetros de fontes de luz spot e mapeamento de revelo entre outros, mantendo o bom desempenho do algoritmo original. Também é estudada a paralelização do algoritmo e outras formas de aceleração do processamento. As extensões propostas permitem ampliar o campo de aplicação do algoritmo original incentivando sua adoção mais generalizada.
Ray tracing is an image synthesis computer algorithm. Its main features are the high quality of the generated images (which incorporate shadows, reflections and transparency, among other effects) and, on the other hand, a high processing demand. Parameterized ray tracing is an algorithm based on ray tracing which allows the synthesis of images with the same quality but tens of times faster than ray tracing, although with some restrictions. These restrictions are the requirement of generating a data file (which takes a little longer than standard ray tracing to create) and the fact that no geometric modifications are allowed. On the other side, the processing time for creating new versions of the image with changes only on optical parameters (colors, light intensities, textures, reflections, transparencies, etc.) is extremely fast. This Ph.D. dissertation proposes extensions to the parameterized ray tracing algorithm for diminishing its restrictions. These extensions allow changing some geometric parameters like the light source positions, spotlight parameters and bump-mapping among others, keeping the processing performance of the original algorithm. The parallelization of the algorithm is also focused as well as other performance enhancements. The proposed extensions enlarge the field of application of the original algorithm, encouraging more general adoption.

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Enfeldt, Viktor. "Real-Time Ray Tracing With Polarization Parameters." Thesis, Blekinge Tekniska Högskola, Institutionen för datavetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-19667.

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Background. The real-time renderers used in video games and similar graphics applications do not model the polarization aspect of light. Polarization parameters have previously been incorporated in some offline ray-traced renderers to simulate polarizing filters and various optical effects. As ray tracing is becoming more and more prevalent in real-time renderers, these polarization techniques could potentially be used to simulate polarization and its optical effects in real-time applications as well. Objectives. This thesis aims to determine if an existing polarization technique from offline renderers is, from a performance standpoint, viable to use in real-time ray-traced applications to simulate polarizing filters, or if further optimizations and simplifications would be needed. Methods. Three ray-traced renderers were implemented using the DirectX RayTracing API: one polarization-less Baseline version; one Polarization version using an existing polarization technique; and one optimized Hybrid version, which is a combination of the other two. Their performance was measured and compared in terms of frametimes and VRAM usage in three different scenes and with five different ray counts. Results. The Polarization renderer is ca. 30% slower than the Baseline in the two more complex scenes, and the Hybrid version is around 5–15% slower than the Baseline in all tested scenes. The VRAM usage of the Polarization version was higher than the Baseline one in the tests with higher ray counts, but only by negligible amounts. Conclusions. The Hybrid version has the potential to be used in real-time applications where high frame rates are important, but not paramount (such as the commonly featured photo modes in video games). The performance impact of the Polarization renderer's implementation is greater, but it could potentially be used as well. Due to limitations in the measurement process and the scale of the test application, no conclusions could be made about the implementations' impact on VRAM usage.
Bakgrund. Realtidsrenderarna som används i videospel och liknande grafikapplikationer simulerar inte ljusets polarisering. Polariseringsinformation har tidigare implementerats i vissa stålföljningsbaserade (ray-traced) offline-renderare för att simulera polariseringsfilter och diverse optiska effekter. Eftersom strålföljning har blivit allt vanligare i realtidsrenderare så kan dessa polariseringstekniker potentiellt också användas för att simulera polarisering och dess optiska effekter i sådana program. Syfte. Syftet med denna rapport är att avgöra om en befintlig polariseringsteknik från offline-renderare, från en prestandasynpunkt, är lämplig att använda för att simulera polariseringsfilter i stålföljningsbaserade realtidsapplikationer, eller om ytterligare optimeringar och förenklingar behövs. Metod. DirectX RayTracing API:et har använts för att implementera tre stålföljningsbaserade realtidsrenderare: en polarisationsfri Baseline-version; en Polarization-version med en befintlig polariseringsteknik; och en optimerad Hybrid-version, som är en kombination av de andra två. Deras prestanda mättes och jämfördes med avseende på frametime och VRAM-användning i tre olika scener och med fem olika antal strålar per pixel. Resultat. Polarization-versionen är ca 30% långsammare än Baseline-versionen i de två mest komplexa scenerna, och Hybrid-versionen är ca 5–15% långsammare än Baseline-versionen i alla testade scener. Polarization-versionens VRAM-användningen var högre än Baseline-versions i testerna med högre strålantal, men endast med försumbara mängder. Slutsatser. Hybrid-versionen har potential att användas i realtidsapplikationer där höga bildhastigheter är viktiga, men inte absolut nödvändiga (exempelvis de vanligt förekommande fotolägena i videospel). Polarization-versionens implementation hade sämre prestanda, men även den skulle potentiellt kunna användas i sådana applikationer. På grund av mätprocessens begränsningar och testapplikationens omfattning så kunde inga slutsatser dras gällande implementeringarnas påverkan på VRAM-användning.

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Lindau, Ludvig. "Hardware accelerated ray tracing of particle systems." Thesis, Blekinge Tekniska Högskola, Institutionen för datavetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-20231.

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Background. Particle systems are a staple feature of most modern renderers. There are several technical challenges when it comes to rendering transparent particles. Particle sorting along the view direction is required for proper blending and casting shadows from particles requires non-standard shadow algorithms. A recent technology that could be used to adress these technical challenges is hardware accelerated ray tracing. However there is a lack of performance data gathered from this type of hardware. Objectives. The objective of this thesis is to measure the performance of a prototype that uses hardware accelerated ray tracing to render particles that cast shadows. Methods. A prototype is created and measurements of the ray tracing time are made. The scene used for the benchmark test is a densely packed particle volume of highly transparent particles, resulting in a scene that looks similar to smoke. Particles are sorted along a ray by repeatedly tracing rays against the scene and incrementing the ray origin past the previous intersection point until it has passed all the objects that lie along the ray. Results. Only a small number of particles can be rendered if real time rendering speeds are desired. High quality shadows can be produced in a way that is very simple compared to texture based methods. Conclusions. Future hardware speed ups can improve the rendering speeds but more sophisticated sorting methods are needed to render larger amounts of particles.

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Schaubach, Kurt Richard. "Microcellular radio channel prediction using ray tracing." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-09122009-040308/.

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Jadi, Tjah. "Implementing ray tracing algorithm in parallel environment." PDXScholar, 1989. https://pdxscholar.library.pdx.edu/open_access_etds/3935.

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Ray tracing is a very popular rendering algorithm in the field of computer graphics because it can generate highly-realistic images from three-dimensional models. Unfortunately, the computational cost is very expensive. To speed up the rendering process we present both static and dynamic scheduling (balancing) strategies for a multiprocessor system. Hence, the load balancing among the processors is the most important problem in parallel processing. The implementation of the algorithm is based on a modified octree structure.

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Lam, Wai Sze Tiffany. "Anisotropic Ray Trace." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/556957.

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Optical components made of anisotropic materials, such as crystal polarizers and crystal waveplates, are widely used in many complex optical system, such as display systems, microlithography, biomedical imaging and many other optical systems, and induce more complex aberrations than optical components made of isotropic materials. The goal of this dissertation is to accurately simulate the performance of optical systems with anisotropic materials using polarization ray trace. This work extends the polarization ray tracing calculus to incorporate ray tracing through anisotropic materials, including uniaxial, biaxial and optically active materials. The 3D polarization ray tracing calculus is an invaluable tool for analyzing polarization properties of an optical system. The 3×3 polarization ray tracing P matrix developed for anisotropic ray trace assists tracking the 3D polarization transformations along a ray path with series of surfaces in an optical system. To better represent the anisotropic light-matter interactions, the definition of the P matrix is generalized to incorporate not only the polarization change at a refraction/reflection interface, but also the induced optical phase accumulation as light propagates through the anisotropic medium. This enables realistic modeling of crystalline polarization elements, such as crystal waveplates and crystal polarizers. The wavefront and polarization aberrations of these anisotropic components are more complex than those of isotropic optical components and can be evaluated from the resultant P matrix for each eigen-wavefront as well as for the overall image. One incident ray refracting or reflecting into an anisotropic medium produces two eigenpolarizations or eigenmodes propagating in different directions. The associated ray parameters of these modes necessary for the anisotropic ray trace are described in Chapter 2. The algorithms to calculate the P matrix from these ray parameters are described in Chapter 3 for anisotropic ray tracing. This P matrix has the following characteristics: (1) Multiple P matrices are calculated to describe the polarization of the multiple eigenmodes at an anisotropic intercept. (2) Each P matrix maps the orthogonal incident basis vectors (Ê_m, Ê_n, Ŝ) before the optical interface into three orthogonal exiting vectors (a_m Ê'_m, a_n Ê'_n, Ŝ') after the interface, where a_m and a_n are the complex amplitude coefficients induced at the intercept. The ray tracing algorithms described in this dissertation handle three types of uncoated anisotropic interfaces isotropic/anisotropic, anisotropic/isotropic and anisotropic/anisotropic interfaces. (3) The cumulative P matrix associated with multiple surface interactions is calculated by multiplying individual P matrices in the order along the ray path. Many optical components utilize anisotropic materials to induce desired retardance. This important mechanism is modeled as the optical phase associated with propagation. (4) The optical path length OPL of an eigenpolarization along an anisotropic ray path is incorporated into the calculation of each P matrix. Chapter 4 presents the data reduction of the P matrix of a crystal waveplate. The diattenuation is embedded in the singular values of P. The retardance is divided into two parts: (A) The physical retardance induced by OPLs and surface interactions, and (B) the geometrical transformation induced by geometry of a ray path, which is calculated by the geometrical transform Q matrix. The Q matrix of an anisotropic intercept is derived from the generalization of s- and p-bases at the anisotropic intercept; the p basis is not confined to the plane of incidence due to the anisotropic refraction or reflection. Chapter 5 shows how the multiple P matrices associated with the eigenmodes resulting from propagation through multiple anisotropic surfaces can be combined into one P matrix when the multiple modes interfere in their overlapping regions. The resultant P matrix contains diattenuation induced at each surface interaction as well as the retardance due to ray propagation and total internal reflections. The polarization aberrations of crystal waveplates and crystal polarizers are studied in Chapter 6 and Chapter 7. A wavefront simulated by a grid of rays is traced through the anisotropic system and the resultant grid of rays is analyzed. The analysis is complicated by the ray doubling effects and the partially overlapping eigen-wavefronts propagating in various directions. The wavefront and polarization aberrations of each eigenmode can be evaluated from the electric field distributions. The overall polarization at the plane of interest or the image quality at the image plane are affected by each of these eigen-wavefronts. Isotropic materials become anisotropic due to stress, strain, or applied electric or magnetic fields. In Chapter 8, the P matrix for anisotropic materials is extended to ray tracing in stress birefringent materials which are treated as spatially varying anisotropic materials. Such simulations can predict the spatial retardance variation throughout the stressed optical component and its effects on the point spread function and modulation transfer function for different incident polarizations. The anisotropic extension of the P matrix also applies to other anisotropic optical components, such as anisotropic diffractive optical elements and anisotropic thin films. It systematically keeps track of polarization transformation in 3D global Cartesian coordinates of a ray propagating through series of anisotropic and isotropic optical components with arbitrary orientations. The polarization ray tracing calculus with this generalized P matrix provides a powerful tool for optical ray trace and allows comprehensive analysis of complex optical system.

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Ernst, Manfred. "Ray tracing techniques for hybrid and photorealistic rendering /." Erlangen : Dept. Informatik, 2009. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=018644254&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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Baumann, Gisela. "Ray-tracing in non-radial envelopes of protostars." Zürich : Institute of Astronomy, Eidgenössische Technische Hochschule Zürich, 2006. http://e-collection.ethbib.ethz.ch/show?type=dipl&nr=264.

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Haggren, Simon. "Mikrovågssimulering med realtidsljus : Realtids-ray tracing i CUDA." Thesis, Högskolan i Skövde, Institutionen för kommunikation och information, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-4391.

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Detta arbete undersöker möjligheterna med att simulera mikrovågor i ett slutet system. Systemet implementeras med en redan befintlig teknik kallad ray tracing. Ray tracing är en ljussättningsteknik som går ut på att simulera fotoners rörelse mellan ljuskälla och betraktare i en miljö man önskar ljussätta, och sedan belysa de områden som blir träffade för att på detta vis rendera en bild. Fotoner och mikrovågor har egenskaper som liknar varandra då de båda är elektromagnetism med olika våglängder. Ray tracing är en krävande algoritm då många uträkningar för varje foton måste utföras varje uppdatering. Därför har algoritmen implementerats med CUDA, ett bibliotek från Nvidia som gör det möjligt att använda GPU:n som ett generellt beräkningssystem. Detta är lämpligt för just den här typen av problem då GPU:ns arkitektur är ämnad för multipla, parallella uträkningar.

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Andersson, Filip Lars Roland. "Real-Time Ray Tracing on the Cell Processor." Thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-95303.

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The first ray casting algorithm was introduced as early as 1966 and was followed by the first ray tracing algorithm in 1979. Since then many revisions to both these algorithms have been presented along with the strong development of computer processors. For a very long time both ray casting and ray tracing were associated with rendering of single images. One single image could take several hours to compute and to date still can for very complex scenes. Only during the last few years have attempts to write algorithms for real time been made. This thesis focuses on the question of how a real time ray caster can be mapped on the Cell Broadband Engine Architecture. It addresses the development of a ray caster on a single unit processor and then goes through the steps on how to rewrite an application to exploit the full potential of the cell broadband engine. This includes identifying the compute intensive parts of the application and parallelizing these over all the available elements in the cell architecture.

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Coulthurst, David James. "Ray tracing methods fo hybrid global illumination algorithms." Thesis, University of Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.555616.

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Global illumination algorithms provide a way to model the different light transport phenomena seen in real life, and produce accurate images. The amount of computation to achieve accurate rendering is large, resulting in the development of many different ways of speeding it up. Some of these focus on speeding up the basic processes of rendering, such as ray tracing operations, and some on leveraging parallel hardware to speed up rendering. Two novel algorithms of this type are described in this thesis. One to allow incoherent paths to be efficiently be traced in parallel by offsetting the latency. The other discovers and exploits empty regions of space to avoid the use of acceleration structures for such operations as soft shadowing and metropolis light transport mutations. The other approach to speeding up rendering is to use a more elegant algorithm. Two such families of algorithms are photon mapping and metropolis light transport. Extensions to progressive photon mapping and hybrid algorithms using photon mapping and metropolis light transport are presented., showing significant speedup in complex scenes that present difficulties to current rendering algorithms.

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Nasedkin, Alexandr. "Tracing Molecular Conformations by X-ray Solution Scattering." Doctoral thesis, Uppsala universitet, Fysikalisk kemi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-230563.

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In the present work the refinement of X-ray data have been used to solve different scientific problems, namely drug localization in the liposome wall, reaction kinetics of the small molecule upon excitation and resolving an ensemble of protein structures at different temperatures. The common approach included collection of X-ray scattering patterns, modelling of the system of interest in atomic level and fitting computed results to experimental data. Employed fitting algorithms varied depends on the application ranging from inverse matrix calculations to the genetic algorithm for complex tasks. Observed results broaden our understanding of investigated systems on molecular level and also lead to development faster, more effective ways to sample atomic structures by X-ray diffusion scattering.

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Samothrakis, Stavros Nikolaou. "Acceleration techniques in ray tracing for dynamic scenes." Thesis, University of Sussex, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241671.

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Reinhard, Erik. "Scheduling and data management for parallel ray tracing." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302169.

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Goh, Eng Lim. "Parallel architectures with fast ray-tracing image synthesis." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335748.

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Glazer, Brendon C. (Brendon Charles) 1975. "Interactive ray tracing of VRML scenes in Java." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80539.

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Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.
Includes bibliographical references (leaves 69-70).
by Brendon C. Glazer.
S.B.and M.Eng.

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Kurita, Hiroyuki 1958. "Interferometric aspheric surface testing using ray tracing code." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/276944.

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Phase shifting interferometry is one of the most promising methods for testing aspheres. However, one will encounter the following problems when it is applied to test an asphere: (1) very tight fringes produced by a strong asphere exceed the test system's resolution, (2) a test wavefront suffers from system aberrations of the interferometer that cause measurement errors, and (3) the wavefront immediately after reflection does not necessarily represent the shape of the test asphere. This thesis used a high density array sensor to detect the dense fringes. In order to solve the system aberration and the ray retrace problems, it is necessary to incorporate a ray trace code and phase shifting interferometry. This measurement principle was applied for an aspheric surface whose asphericity was 100 waves. A phase shifting Fizeau interferometer was incorporated with an optical design program. The attained accuracy was approximately one-tenth of a wave.

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Faria, Antonio Augusto Araujo. "Radio propagação indoor utilizando ray tracing força bruta." [s.n.], 1996. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259673.

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Orientador: Michel Daoud Yacoub
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
Made available in DSpace on 2018-07-22T10:45:59Z (GMT). No. of bitstreams: 1 Faria_AntonioAugustoAraujo_M.pdf: 5745129 bytes, checksum: 9f92969853a8b36b71f883f7524c5ce4 (MD5) Previous issue date: 1996
Resumo: Este trabalho utiliza um método ray-tracing para a predição de cobertura no interior de edifícios em um único andar. Algumas inovações foram acrescentadas a um modelo existente, como a abordagem estatística para o cálculo do excesso de perdas, e a inclusão de portas nos ambientes. Alguns resultados foram obtidos para diferentes situações, verificando a possibilidade da otimização do posicionamento do transmissor
Abstract: This work uses a ray tracing method for an indoor building coverage prediction applied to a single floor. Contributions are added to an existent model, like a statistical approach for the excess path loss calculation, and inclusion of doors. Some results are presented for different situations, showing the optimization possibility of the transmitter position
Mestrado
Mestre em Engenharia Elétrica

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Santos, Eduardo Toledo. "Avaliação do algoritmo de "ray tracing" em multicomputadores." Universidade de São Paulo, 1994. http://www.teses.usp.br/teses/disponiveis/3/3141/tde-31032004-123720/.

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A Computação Gráfica, área em franco desenvolvimento, têm caminhado em busca da geração, cada vez mais rápida, de imagens mais realísticas. Os algoritmos que permitem a síntese de imagens realísticas demandam alto poder computacional, fazendo com que a geração deste tipo de imagem, de forma rápida, requeira o uso de computadores paralelos. Hoje, a técnica que permite gerar as imagens mais realísticas é o "ray tracing" . Os multicomputadores, por sua vez, são a arquitetura de computadores paralelos mais promissora na busca do desempenho computacional necessário às aplicações modernas. Esta dissertação aborda o problema da implementação do algoritmo de "ray tracing" em multicomputadores. A paralelização desta técnica para uso em computadores paralelos de memória distribuída pode ser feita de muitas formas diferentes, sempre envolvendo um compromisso entre a velocidade de processamento e a memória utilizada. Neste trabalho conceitua-se este problema e introduz-se ferramentas para a avaliação de soluções que levam em consideração a eficiência de processamento e a redundância no uso de memória. Também é apresentada uma nova taxonomia que, além de permitir a classificação de propostas para implementações de "ray tracing" paralelo, orienta a procura de novas soluções para este problema. O desempenho das soluções em cada classe desta taxonomia é avaliado qualitativamente. Por fim, são sugeridas novas alternativas de paralelização do algoritmo de "ray tracing" em multicomputadores.
Computer Graphics is headed today towards the synthesis of more realistic images, in less time. The algorithms used for realistic image synthesis demand high computer power, so that the synthesis of this kind of image, in short periods of time, requires the use of parallel computers. Nowadays, the technique that yields the most realistic images is ray tracing. On its turn, multicomputers are the most promising parallel architecture for reaching the performance needed in modern applications. This dissertation is on the problem of implementing the ray tracing algorithm on multicomputers. The parallelization of this technique on distributed memory parallel computers can take several forms, always involving a compromise between speed and memory. In this work, this problem is conceptualized and tools for evaluation of solutions that account for efficiency and redundancy, are introduced. It is also presented a new taxonomy that can be used for both the classification of parallel ray tracing proposals and for driving the search of new solutions to this problem. The performances of entries in each class of the taxonomy are qualitatively assessed. New alternatives for parallelizing the ray tracing algorithm on multicomputers, are suggested.

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Dissertations / Theses on the topic 'Ray tracing'

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