The goal of this thesis is to develop a procedural terrain height map generator programmable using a Turing complete scripting language. The generator must allow rendering of partial maps by generating arbitrary rectangular region of the map described by any script. The thesis explains why this means the traditional script execution model won't work in this case and proposes a novel two stage model, which executes the scripts in two stages - a simulation stage and a rendering stage. Powered by TCPDF (www.tcpdf.org)

Delaunay refinement is a mesh triangulation method with the goal of generating well-shaped triangles to obtain a valid Delaunay triangulation. In this thesis, an approach of using this method for meshing continuous height field terrains is presented using Perlin noise as the height field. The Delaunay approach is compared to grid-based meshing to verify that the theoretical time complexity O(n log n) holds and how accurately and deterministically the Delaunay approach can represent the height field. However, even though grid-based mesh generation is faster due to an O(n) time complexity, the focus of the report is to find out if Delaunay refinement can be used to generate meshes quick enough for real-time applications. As the available memory for rendering the meshes is limited, a solution for providing a cohesive mesh surface is presented using a hole filling algorithm since the Delaunay approach ends up leaving gaps in the mesh when a chunk division is used to limit the total mesh count present in the application. The methods were implemented in the programming language C++ using the open source library libnoise to generate the Perlin noise and the off-the-shelf solution CGALmesh provided a Delaunay refinement implementation. The video game engine Unity was used to render the output meshes created by the Delaunay and grid approach by interfacing with C++ via a Windows DLL. The time complexity of Delaunay refinement was verified to hold, although it was not possible to draw any conclusions regarding the Delaunay refinement's impact on the mesh's accuracy due to the test parameters used. It was also found that the CGALmesh implementation failed to provide a deterministic generation which is a significant drawback compared to the grid-based approach. Disregarding this, the Delaunay approach was found to be suitable for real-time applications as the generation time took less than 1 second, and is promising for volumetric terrain mesh generation. / Delaunay-raffinemang är en trianguleringsmetod med målet att generera reguljära trianglar för att uppnå en giltig Delaunay-triangulering. I denna avhandling presenteras en metod användandes Delaunay-raffinemang för att skapa polygonytor av kontinuerliga höjdfältsterränger, där Perlin noise används som höjdfält. Delaunay-metoden jämförs med en rutnätsbaserad metod för att verifiera att tidskomplexiteten O(n log n) gäller och hur exakt och deterministiskt som Delaunay-metoden förhåller sig till att representera höjdfältet. Även fast rutnätsmetoden är snabbare på grund av en O(n) tidskomplexitet är rapportens fokus att ta reda på om Delaunay-raffinemang är snabb nog för att användas i realtidsapplikationer för att generera polygonytor. Eftersom det tillgängliga minnet för att rendera polygonytorna är begränsat presenteras en lösning för att få sammanhängande ytor genom en hålutfyllningsalgoritm då Delaunaymetoden lämnar hål i ytan när chunk-uppdelning används för att begränsa det totala antalet polygonytor i applikationen. Metoderna implementerades i programmeringsspråket C++ användades biblioteket libnoise för att generera Perlin noise och den färdiga lösningen CGALmesh användes som implementation av Delaunay-raffinemang. Datorspelsmotorn Unity användes för att rendera polygonytorna som skapades av Delaunay- och rutnätsmetoden genom ett C++-gränssnitt via en Windows DLL. Tidskomplexiteten av Delaunay-raffinemang gällde, men det var inte möjligt att dra några slutsatser gällande hur exakt metoden förhållde sig till höjdfältet på grund av testparametrarna som användes. Ytterligare visade det sig att CGALmesh-implementationen var oförmögen att deterministiskt generera ytorna vilket är en stor nackdel jämfört med rutnätsmetoden. Bortsett från detta så visade sig Delaunay-metoden användbar för realtidsapplikationer då generingstiden tog mindre än 1 sekund, och metoden har dessutom potential för volymetrisk terränggenerering.

This thesis focuses on the design and implementation of a software system enabling out-of-core rendering of multiple map datasets mapped on virtual globes around our solar system. Challenges such as precision, accuracy, curvature and massive datasets were considered. The result is a globe visualization software using a chunked level of detail approach for rendering. The software can render texture layers of various sorts to aid in scientific visualization on top of height mapped geometry, yielding accurate visualizations rendered at interactive frame rates. The project was conducted at the American Museum of Natural History (AMNH), New York and serves the goal of implementing a planetary visualization software to aid in public presentations and bringing space science to the public. The work is part of the development of the software OpenSpace, which is the result of a collaboration between Linköping University, AMNH and the National Aeronautics and Space Administration (NASA) among others.

This document discusses a problem of tooth detection on jaw 3D polygonal model. It describes known methods that can be used to reach expected results, such as their advantages and disadvantages. Considering this, I choose one solution that is closely described with all theory needed for its implementation.

This document discusses a solution for tooth classification on 3D jaw polygonal model. Sequentially, I describe techniques for representation and browsing of polygonal model saved in computer memory, techniques for dental curve detection and finally, creation of surface representing approximated tooth plane. After it, I analyze possibilities of height map creation from jaw model which helps in tooth classification in the scope of entire dental curve context and, as a last step, final detection of these teeth in two dimensions. In the same time, I discuss 3D polygonal model segmentation for border extraction, which separates teeth from the rest of the model. In the end of proposed algorithm, I join these two runs into one final detection and classification process of separate teeth, so presented application can automatically indentify and classify teeth to corresponding names and positions with a minimum user interaction. In a second half of this document, I describe implemented solution. According to primary goal, I propose these techniques forcefully to multiplatform approach and maximal user comfort.

Thanks to the increasing computation power the complexity and dynamism of virtual reality is continuously improving. This work aims to examine influences of weather in a landscape and the means to simulate and dynamically visualize them in real time on the current personal computer hardware. The main goal is to find quick well looking approximations rather than a complex physically correct simulation. The work covers using modern programmable GPU not only for visualization but also as a powerful simulation instrument. The main topic is water movement in the terrain and its effects on it like erosion, snow melting and moisture impact on vegetation. This requires dynamic terrain texturing and algorithms supporting fast geometry and normals updates.