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- Institut für Computervisualistik (18) (remove)
This thesis imparts a general view of the mechanics and implementation of latest voxelization strategies using the GPU. In addition to established voxelization procedures using the rasterization pipeline, new possibilities arising from GPGPU programming are examined. On the basis of the programming language C++ and the graphics library OpenGL the implementation of several methods is explained. The methods are compared in terms of performance and quality of the resulting voxelization and are evaluated critically with regards to possible use cases. Furthermore, two exemplary applications are detailed that use a voxelized scene in such a way that the augmentation of established techniques of real time graphics are facilitated. To this end, the concepts and the implementations of Transmittance Shadow Mapping and of Reflective Shadow Mapping utilizing a voxel based ambient occlusion effect is explained. Finally, the prolonging relevance of voxelization is put into prospect, by addressing latest research and further enhancements and applications of the presented methods.
The animation of models has become an important part in different areas of everyday life. It is a demanding task for computer graphics to generate
a natural deformation of organic models. Skinning is a common method to animate models without animating each vertex individually. The skin of the model deforms automatically by manipulating individual bones of a skeleton.
This bachelor thesis deals with the most common algorithm, linear blend skinning and aims to find some optimizations regarding the visual effect
and performance. Additionally it presents certain instancing methods which are combined with the skinning methods in the application to show the advantages and disadvantages of the latter.
This work presents an application for simulation objects, which can change their aggregate states between solid and liquid using a temperature system. The focal points are the simulation of fluids with a particle system, the generation of a surface and the visualization of metal. The application should be interactive and match the real time conditions. Different types of Shader are used for the parallelized computations on the GPU. Also more options to use the application and possible improvements are presented.
Tiny waves driven by wind, shallow, long waves, head overlapping sea, all of these waves occur in every ocean and even in small lakes. The surface of water is one of the most versatile phenomenas of nature. Not only the movement of waves, but also the reflection of sky, sun and coastline makes the surface of water unique. Exactly this complexity is what brings its own challenges to the simulation of water surfaces. That is why simulation of water occupies mathematicians with a challenge for nearly 400 years now.
In the last fifty years this challenge has more and more shifted to computer science. Computer graphic designers have tried to visualise water in a realistic manner for centuries. Science in this field expends from simple noise filters to mathematically complex solutions like Fourier Transformation.
In the following work historical background of todays wave theories, as well as mathematical fundamentals are given. The focus of this work is set on the implementation of these methods in OpenGL 3.3.
In the man-machine interaction tracking and identification of individuals plays an important role. In this work, a framework for the service-robot Lisa, of the Active Vision Group, has been created to combine different methods for the detection, tracking and identification of individuals. First leg detection is performed to establish hypotheses for people using a 2D-laserscan. This assumption needs to be confirmed by an analysis of the Kinect point cloud. After successful confirmation online-boosting on RGB-data is performed for identification. The leg data will also be used with a linear Kalman filter to estimate the movement of people. Through the combination of of Kalman filter with leg detection and online-boosting people tracking should be enabled. Further receiving an interchange of persons should - by brief occlusion or faulty associate of legs - can be prevented.
The present thesis covers the implementation and optimization of global illumination in three-dimensional scenes. Global illumination does not only consider direct illumination dependent on one or more light sources, but also indirect illumination which is emitted by surrounding objects in the scene. The thesis focuses on the implementation of a global illumination method and its improvement using OpenGL 4.4. This is done by a voxelization of the scene. By traversing the resulting voxel structure, additional information is taken from the scene, which contributes to a plausible global illumination.
Online Handschrifterkennung chinesischer Schriftzeichen auf androidfähigen mobilen Endgeräten
(2014)
Usage of mobile dictionaries or translators requires an input. This input has to be processed and recognized beforehand. Chinese characters are more suited for a handwritten input than a keyboard based one. Reason for that are the characters consisting mostly of pictograms or ideograms.
This thesis deals with an implementation of a prototypical recognition system on a mobile device. The recognition process should be online and therefore running while writing. It can save time for the user, because suggestions are made during runtime.
Basics and an overview over the current state of the art in online handwriting recognition will be given. An approach will be chosen and implemented, such that the recognition process is fast and needs little memory. The implementation will be tested and it will show, that a fast recognition can be possible on small devices. Suggestions for expansions and improvements will be given, including a future work part.
This thesis covers the mathematical background of ray-casting as well as an exemplary implementation on graphics processing units, using a modern programming interface. The implementation is embedded within an editor, which enables the user to activate optimizations of the algorithm. Techniques like transfer functions and local illumination are available for a more realistic visualization of materials. Moreover, the user interface gives access to features like importing volumes, let one define a custom transfer function, holds controls to adjust parameters of rendering and allows to activate further techniques, which are also subject of discussion in this thesis. Benefit of all shown techniques is measured, whether it is expected to be visual or on the part of performance.
Ziel der Bachelorarbeit war es, eine moderne Art des Geländespiels "Schnitzeljagd" zu entwickeln. Dieses sollte möglichst auf jedem aktuellen Smartphone spielbar sein, welches mit dem Betriebssystem Android arbeitet. Das Gelände ist begrenzt auf den Universitätscampus Koblenz, somit dient das Spiel auch dazu, den Campus besser kennenzulernen.
Den Benutzern der Campusjagd wird eine mobile Applikation geboten, welche sie anhand von Hinweisen und Rätseln über den kompletten Campus führt, um letztendlich an einen Zielort zu gelangen, an welchem sich ein "Schatz" befindet. Anstatt wie üblich auf dem Gelände Schnitzel bzw. Schnipsel mit Hinweisen zu verstecken, werden bei der Campusjagd QR-Codes aufgehängt, um so den Weg zu markieren. Zur Täuschung sind auch irrelevante Codes zu finden. Die Codes müssen in der richtigen Reihenfolge abgelaufen werden, d. h. von einem Code erhält der Spieler den Hinweis zum jeweiligen Nächsten. Außerdem ist es möglich, dass aus einem QR-Code mehrere Hinweise für nächste Stationen angezeigt werden.
The goal of this work is evaluation and optimization of several eye-tracking algorithms for estimation of relevant features regarding accuracy. The extracted features are pupil- and glintcenters. The algorithms are applicable to off the shelf cameras. A synthetic model of the eye was modified and utilized. The model was used to supply ground truth for the evaluation of the methods.