The object of this work is to create software implementing two algorithms for global ilumination computing. Iradiance and radiance caching should be implemented in CUDA framework on graphics card (GPU). Parallel implementation on GPU should dramatically improve algoritm speed compared to CPU implementation. The software will be written using already done framework for global illumunation computation. That allow to focus to algorithm implementation only. This work should speed up testing of new or existing methods for global illumination computing, because saving and reusing of intermediate results can be used for other algorithms too. Powered by TCPDF (www.tcpdf.org)

How important is a perfect index of refraction value for the look of a material? Does everything have to be physically accurate to be percieved as a photorealistic material? There are some aspects of a lot of materials that is already physically measured, like its reflectance values. Are all these measurements enough to create a material that can be percieved as photorealistic, or are there other more diffuse things that needs and artistic input? This paper will take silver as an example. Silver often has two distinct types of oxidation: one semi-transparent yellow-ish coating and one more black opaque tarnish. Is this something that can be dialed in from derived data? What properties of the metal will change when the oxidation occurs and how will it affect it look of it from a shading perspective? Silver utilitys will be thoroughly examined to make out what important visual cues there are, and what they are made of. This information will then be used to create a silver material that could be percieved as real. A reference silver cup will be used as a comparison next to the rendered material.

Title: Sound simulation of granular materials Author: Matej Marko Department: Department of Software and Computer Science Education Supervisor: doc. Ing. Jaroslav Křivánek Ph.D., Department of Software and Computer Science Education Abstract: In recent years, methods for simulating sounds of solid objects, fluids, fire and cloth have been developed. These methods extend existing methods for simulation of the visual behaviour of the respective phenomena and add physically based sounds that correspond with the visual information. The goal of this thesis is to investigate the possibility of creating a similar method for sound simulation of dry granular materials. We identified two distinct mechanisms responsible for the sounds of granular materials: the collisions of the particles of the granular material (granular collisions) and the collisions between the particles and a surrounding solid objects (solid objects collisions). We propose a method that uses acceleration noise to simulate the sounds of the granular collisions. The particles are approximated by a simplified spherical shapes. We also simulate the sound of the solid object collisions by using a modal analysis approach. Since most of the approaches to the visual simulation of granular materials do not provide the information about the particle...

The objective of this work is to create software implementing two algorithms for global ilumination computation. Iradiance and radiance caching should be implemented in CUDA framework on a graphics card (GPU). Parallel implementation on the GPU should improve algoritm speed compared to CPU implementation. The software will be written using an already done framework for global illumunation computation. That allows to focus on algorithm implementation only. This work should speed up testing of new or existing methods for global illumination computing, because saving and reusing of intermediate results can be used for other algorithms too. Powered by TCPDF (www.tcpdf.org)

Master of Science / Department of Computing and Information Sciences / William H. Hsu / Automatic rigging is a targeting approach that takes a 3-D character mesh and an adapted skeleton and automatically embeds it into the mesh. Automating the embedding step provides a savings over traditional character rigging approaches, which require manual guidance, at the cost of occasional errors in recognizing parts of the mesh and aligning bones of the skeleton with it. In this thesis, I examine the problem of reducing such errors in an auto-rigging system and apply a density-based clustering algorithm to correct errors in a particular system, Pinocchio (Baran & Popovic, 2007). I show how the density-based clustering algorithm DBSCAN (Ester et al., 1996) is able to filter out some impossible vertices to correct errors at character extremities (hair, hands, and feet) and those resulting from clothing that hides extremities such as legs.

Call number: LD2668 .P7 1973 M39

The use of Procedural Modeling for the creation of 3D models such as Buildings, Terrains, Trees etc., is becoming increasingly common in Films, Video Games, Urban Modeling and Architectural Visualization. This is due to the primary factor that using procedural models in comparison to traditional hand-modeled models helps in saving time, cost and aids in generation of a larger variety in comparison to a few. However, there are so many open problems in procedural modeling methods that does not rely on any user assistance or aid in generating models especially in terms of their visual quality and perception. Although, it is easy to identify realistic looking models from procedural models, the metrics that make them ’Real’ or ’Procedural’ is still in the indeterminable and remains uncanny in nature. The perceptual metrics (intrinsic factors such as surface features and details, extrinsic factors such as environmental attributes and visual cues) that contributes to the visual perception of Procedural models have not been studied in detail or quantified yet. This dissertation presents a first step in the direction of perceptual evaluation of procedural models of terrains. We gathered and categorized several types of real and synthetic terrains generated by methods used in computer graphics and conducted two large studies with 70 participants ranking them perceptually.<br><br>The results show that synthetic terrains lack in visual quality and are perceived worse than real terrains with statistical significance. We performed a quantitative study by using localized geomorphology based landform features on terrains (geomorphons) that indicate that valleys, ridges, and hollows have significant perceptual importance. We then used generative deep generative neural network to transfer the features from real terrains to synthetic ones and vice versa to further confirm their importance. A second perceptual experiment with 128 participants confirmed the importance of the transferred features for visual perception. Based on these results, we introduce PTQM (Perceived Terrain Quality Metrics); a novel perceptual metrics based on geomorphons that assigns a number of estimated visual quality of a terrain represented as a digital elevation map. The introduced perceptual metric based on geomorphons indicate that features such as Valley (0.66), Ridge (0.64), Summit (0.44), Depression (0.42), Spur(0.33), and Hollow (0.22) in order have significant perceptual importance. By using linear regression, we show that the presented features are strongly correlated with perceived visual quality.<br>

With the increasing size of 3D environments manual modelling becomes a more and more difficult task to perform, while retaining variety in the assets. The use of procedural generation is a well-established procedure within the field today. There have been multiple works presented within the field before, but many of them only focus on certain parts of the process. In this thesis a system is presented for procedurally generating complete build- ings, with an interior. Evaluation has shown that the developed system is compa- rable to existing systems, both in terms of performance and level of detail. The resulted buildings could be utilized in real time environments, such as computer games, where enterable buildings often are a requirement for making the envi- ronment feel alive.

[pt] Em geologia sedimentar estudam-se as formações e evoluções de sedimentos que formam camadas rochosas que encobrem a crosta terrestre. Diferentes processos físicos, químicos e biológicos são responsáveis pela formação e distribuição de sedimentos. Em um ambiente subaquoso são predominantes as rochas sedimentares de origem terrígena e carbonática. As rochas carbonáticas são oriundas de processos químicos, bioquímicos e aloquímicos envolvendo a deposição e decomposição de organismos ricos em cálcio como algas, conchas e corais. Essas rochas vêm sendo amplamente estudadas na indústria de óleo e gás, pois podem ser bons reservatórios de hidrocarbonetos. Tendo em vista a importância destas rochas, este trabalho concentra-se na formação e evolução de plataformas carbonáticas, existentes principalmente em ambientes de águas quentes e claras. Neste contexto, é proposto um modelo matemático determinístico que possa representar a evolução de plataformas carbonáticas dados alguns parâmetros iniciais como a subsidência inicial, taxas de crescimento e variações do nível do mar. Em cima deste modelo matemático foi desenvolvido um simulador computacional de sedimentação carbonática tridimensional, CarbSM, que leva em conta três fábricas carbonáticas: interior da plataforma, borda da plataforma e águas profundas. Com esses ambientes são associadas taxas máximas de crescimento in situ, além de funções restritivas, tais como: profundidade, condições marinhas e sedimentação terrígena; possibilitando o cálculo das taxas resultantes. Desta forma, o sistema é capaz de simular a evolução de plataformas carbonáticas em diversos cenários geológicos. Para entrada de dados e análise dos resultados obtidos, CarbSM oferece uma extensa interface ao usuário e utiliza técnicas de computação gráfica para visualização tridimensional interativa dos modelos. / [en] Sedimentary geology focuses on the formation and evolution of the Earth’s surface. Various physical, chemical and biological processes are responsible for supplying and distributing sediments. The presence of sedimentary rocks of siliciclastic and carbonate origins are dominant in subaqueous environments. Carbonate rocks are originated from biochemical processes involving the deposition and decomposition of calcium rich organism such as algae, shells and corals. These types of rocks are of great interest for the oil and gas industry due to their potential to form good hydrocarbon reservoirs. Therefore, this work studies the formation and evolution of carbonate platforms, most common in clear and hot waters. A deterministic mathematical model is proposed to represent the evolution of carbonate platforms given a set of entry data like initial subsidence, growth rates and sea level fluctuations. Based on this mathematical model a tridimensional carbonate sedimentation computational simulator, CarbSM, was developed taking into account three carbonate factories: platform interior, platform margin and deep-water carbonates. These environments are linked to maximum in situ growth rates and the resulting rates are obtained through a series of restriction functions, such as: depth, marine conditions and clastic sedimentation. This way, the developed tool can simulate the evolution of carbonate platforms within diverse geological scenarios. CarbSM offers an extensive user interface and uses computer graphics rendering techniques for data input and interactive tridimensional visualization of the simulated models.

Procedural modeling is a powerful technique used in computer graphics to create geometric models. Instead of manual geometry definition, models are generated implicitly from a set of rules and parameters. Procedural systems have found widespread use in generating content for games, film, and simulation of natural phenomena. Their strength comes from the ability to automatically generate large amount of varied geometry. One of their drawbacks is lack of control because a small change in input parameters often causes large changes in the generated model. <br>In this work we present three novel procedural systems, investigate different forms of control, namely simulation and optimization, and discuss them in terms of general procedural modeling workflow. First we show modeling of 3D objects with arbitrary topology via erosion and deposition simulation controlled by Smoothed Particle Hydrodynamics. Next, we present an algorithm for generating 3D curves using 2D sketches and contextual geometry. Finally, we propose a novel procedural system capable of generating arbitrary type of geometry with respect to user-defined constraints. <br>We show that these systems can be controlled via several means and identify common preconditions that facilitate control: maximizing interactivity and amount of structured information input, minimizing unexpected behaviour, and local control akin to traditional modeling.