Bachelor Thesis
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- Institut für Computervisualistik (100) (remove)
The present thesis gives an overview of the general conditions for the programming of graphics cards. For this purpose, the most important Application Programming Interfaces (APIs) available on the market are presented and compared. Subsequently, two standard algorithms from the field data processing, prefix sum and radixsort are presented and examined with regard to the implementation with parallel programming on the GPU. Both algorithms were implemented using the OpenGL-API and OpenGL compute shaders. Finally, the execution times of the two algorithms were compared.
In dieser Arbeit wird ein System zur Erzeugung und Darstellung stereoskopischen Video-Panoramen vorgestellt. Neben der theoretischen Grundlagen werden der Aufbau und die Funktionsweise dieses Systems erläutert.
Dazu werden spezielle Kameras verwendet, die Panoramen aufnehmen
können und zur Wiedergabe synchronisiert werden. Anschließend wird ein Renderer implementiert, welcher die Panoramen mithilfe einer VirtualReality Brille stereoskopisch darstellen kann. Dafür werden separate Aufnahmen für die beiden Augen gemacht und getrennt wiedergegeben. Zum Abschluss wird das entstandene Video-Panorama mit einem Panorama eines schon bestehenden Systems verglichen.
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 bachelor thesis deals with the conception, implementation and evaluation of a Jump'n'Run game and the consideration of the influence of achievment systems on players. In the game Age of Tunes you play Bardur, the beardless bard and have to try to free the cursed magical creatures in the world Harmonica. The emphasis of the thesis was the clean conception and gradual development of the game, appealing graphic quality, integration of opponents, a mini-game and the consideration of effects of an achievment system on players. In a final evaluation the game and the behavior could be evaluated regarding the achievments.
There are a few systems high and low-cost ones for gaze tracking. Normally low-cost systems go in hand with low-resolution cameras. Here the image quality is poor, so the algorithms for detecting the gaze have to work more precisely. But how to test and analyse them correctly, when there is a bad image quality and no reference point known? The idea of this work is, to generate synthetic eye images, where the reference points are known, because they are mainly manually set and then to test and analyse the algorithms with these synthetic images. By switching on features like gaussian noise or a second glint-like reflection point, it is possible to stepwise approximate the synthetic images close to reality. In fact the experiments will lead to an improvement of the algorithms used in a low-resolution system environment.
Deformable Snow Rendering
(2019)
Accurate snow simulation is key to capture snow's iconic visuals. Intricate
methods exist that attempt to grasp snow behaviour in a holistic manner. Computational complexity prevents them from reaching real-time performance. This thesis presents three techniques making use of the GPU that focus on the deformation of a snow surface in real-time. The approaches are examined by their ability to scale with an increasing number of deformation actors and their visual portrayal of snow deformation. The findings indicate that the approaches maintain real-time performance well into several hundred individual deformation actors. However, these approaches each have their individual restrictions handicapping the visual results. An experimental approach is to combine the techniques at reduced deformation actor count to benefit from the detailed, merged deformation pattern.
In this bachelor thesis, the question of whether or not a jump'n run game with sensor control for android devices is useful, is handled. To this end, a game was developed, which is once controlled with and without sensors at different levels. In a second version, the game is completely controlled by means of sensors, so that the controls can later be compared. It is explained how the game was planned, designed and investigated. In addition, it is checked whether games with sensor control already exist. The engine, which was used to developed the game, is also introduced. Finally, the evaluation is carried out for an elaborated user test on the playability of the game in terms of control.
The following work describes the prototypical conception and development of the stat-raising game "Adventurer's Guild" using the game engine Ren'Py. The game's narrative is influenced by player decisions and the planning of activities. The game is to be visually pleasing and enjoyable.
After giving an overview of stat-raising as a genre, the existing games "Dandelion - Wishes Brought to You", "Pastry Lovers", "Long Live the Queen" and "Magical Diary" are analysed to pinpoint various strengths and weaknesses of their different takes on the genre.
The resultant findings are used for the conception of a new stat-raising game.
The game mechanics and the design decisions made are then shown in screenshots and thoroughly explained.
In a final assessment, the game will be examined with regard to the given task. Further possibilities for potential improvements and expansions will be detailed at the end.
This bachelor thesis’s objective is to offer the reader insight into the discrete Fourier transform, the discrete cosine transform and the discrete Hadamard-Walsh transform in the context of image processing, and also to compare these transformations under various aspects. For this purpose the term of transformation, originated in linear algebra, will be explained and applied to image processing. Subsequently, the understanding of the Fourier transform will successively be built up and connected to the two remaining transforms. Finally, the transformations will be compared and their usefulness in relation to image processing will be explained.
Augmented reality is being present for many years. Through progress in technology smaller augmented reality glasses became possible. These new technologies allow many new ways of interaction and usage of augmented reality.
This thesis is about the Microsoft HoloLens and its possiblities for consumers and industry. In the context of this thesis a new interactive and augmented application to measure the possiblities and limitations of the Microsoft HoloLens has been developed. The scene is an assembly szenario with a step by step instruction of building with Lego bricks. The evaluation showed that the HoloLens can already be used to assist in assembling scenarios and offers some advantages over other methods, although the glasses still have some flaws.
The aim of this work is to develop a simple concept for monitoring dogs that are alone at home for several hours. The prototypical implementation of such a "DogCam" can be considered as proof of concept. The basis for the prototype‘s implementation are the requirements identified within a conducted requirement analysis. Furthermore, the present work shows which improvements and extensions of the prototypical "DogCam" are possible and which similar projects already exist.
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.
In dieser Arbeit wird die Konzeption, Implementierung und Evaluierung einer Augmented Reality-App beschrieben. Diese wurde mit dem Ziel entwickelt, Objekte im realen Raum mit virtuellen Hilfsmitteln auszumessen, sodass diese Anwendung einen Holzgliedermaßstab ersetzen kann. Hinzu kommt die praktische Speicherung der Messwerte. Angefertigt wurde die App mit der Unity Engine und programmiert in C#.
Schwerpunkte dieser Arbeit sind die Benutzerfreundlichkeit der App, sowie die Eignung von AR Foundation für das Ausmessungstool.
Die Anwendung wird auf die genannten Kriterien im Rahmen eines Nutzertests in einer abschließenden Evaluation bewertet.
Als Ergebnis ließ sich festhalten, dass sich die AR-App noch im Prototyp-Stadium befindet, aber im Allgemeinen schon als benutzerfreundlich gilt. Kleinere Änderungen sollen und müssen noch vorgenommen werden, um auch den Umgang mit dem AR-Tool zu vereinfachen.
This thesis explores different approaches for the acceleration of raytracing calculations on the graphics processing unit (GPU). For that a voxel grid is used and extended by the linespace data structure. The linespace consists of direction based shafts and stores the objects located in those shafts in a candidate list. Different methods for the sorting and traversal of the linespace are presented and evaluated. The shown methods cannot provide a speed up of the frame rate without resulting in a loss of image quality.
Algorithmische Komposition
(2018)
Algorithmic composition is an interdisciplinary topic that unites music and science. The computer is able to generate algorithmic music with the aid of a specific algorithm. In this bachelor thesis, algorithmic composition is realized with the biology-inspired algorithms called Lindenmayer-system and cellular automaton. In order to realize the compositions, several techniques are presented as well as implemented and evaluated. Those techniques map the generated data from the algorithms on a meaningful musical result.
The present thesis describes the development of an OpenGL-based tool visualizing cavities of proteins, which can be observed during a static docking simulation. The goal is to achieve knowledge about interactions between proteins and ligands based on information about distances between them. At first chemical basics, which motivate the topic and are important for understanding the topic and the used algorithms, are presented. Furthermore existing software, which deals with similar issues, is described. Next the prerequisites for the development of the program are presented and the tool is described in detail. Concluding the tool is evaluated concerning performance and usage and a summarizing conclusion is given. The program turns out as a helpful tool for current research and a good base for further and deeper research projects.
In this bachelor thesis a code for astrophysical self-gravitating fluid
simulation is developed. The code runs mainly on the GPU. Minimal
simplifications of the physical model and some parameters for accuracy
and tuning allow simulations to be performed at interactive framerates
on most modern consumer grade computers that feature a dedicated
graphics card. It is used to simulate the birth of stars from a turbulent
molecular cloud. Multiple features of star formation, like accretion
discs and fragmentation, can be observed in the simulation, even when
low particle counts are used.
This bachelor thesis deals with the development of an application for the Microsoft HoloLens. The application is used for the marketing of advertis- ing spaces that belongs to the company awk AUSSENWERBUNG GmbH. On basis of the development, the question is answered which are the pos- sibilities and limitations of the HoloLens and the Mixed Reality Platform. Problems are also addressed, that come along with the development of an application for such a new technology, like the HoloLens is. Beside the new technologies, some challenges come also from the applications oper- ational locations. Several application examples and presentations suggest, that the HoloLens is primarily designed for indoor usage. Instead the de- veloped application is for outdoor use only. During the development, sev- eral insights can be gained about this new technology. On the one hand it becomes clear, that the HoloLens and also the development environment aren’t completely matured yet. On the other hand, that the HoloLens isn’t an outdoor device at all. Despite the difficulties during the development, there occur many possibilities that are associated with this new technology.
This thesis presents a novel technique in computer graphics to simulate realtime
global illumination using path tracing. Path tracing is done with compute shaders on the graphics card (GPU) to perform rendering in a highly parallelized manner. To improve the overall performance of tracing rays, the Line Space is used as an acceleration data structure in different variations, resulting in better
empty space skipping. The Line Space saves scene information based on a previous voxelization in direction-dependent shafts and is generated and traversed on the GPU. With this procedure, indirect lighting and soft shadows can be computed in a physically correct way. Furthermore, using the Line Space, path tracing can be performed mostly independent of the complexity of the scene geometry with over 100 frames per second, which is truly real-time and much faster than using a comparable voxel grid. The image quality is not affected negatively by this technique and the shadow quality is in most cases much better compared to shadow-mapping.
In der Computergrafik stellte die Berechnung von Reflexionen lange ein
Problem dar. Doch mit der ständigen Weiterentwicklung der Hardware
und Vorstellung neuer Verfahren ist eine realitätsnahe,
echtzeitfähige(durchschnittlich 60 FPS) Berechnung von Reflexionen möglich. In der folgenden Ausarbeitung werden verschiedene Reflexionsverfahren vorgestellt. Alle mathematischen und physikalischen Grundlagen werden gegeben, um die Algorithmen nachvollziehen zu können. Da eine Reflexion immer das Abtasten eines reflektierten Vektors bedeutet, werden zwei verschiedene Abtastungsverfahren für blickabhängige Reflexionen vorgestellt und anschließend implementiert. Zuletzt werden die Verfahren auf Basis von Qualität und Performance gegenübergestellt.
Helicopters are crucial in today’s life. A vast amount of applications prove
their range, which are not coverable by other types of aircraft. But they are
very complex systems, both, technically and physically. This is one of the
reasons why pilot training for helicopters is quite challenging. In the last
two decades flight simulators became a supplementary instrument in the
educational process of pilots. With flight simulators it is possible to replay
uncommon or dangerous situations. In this thesis a simple flight simulator
for helicopters will be developed based on rigid body physics. The foundation is a simplified rotor model which omits complex fluid dynamics. This
helps to keep the implementation simple and illustrative as well as provide simulation rates at real-time. The modules are implemented within
the Unreal Engine in such way, that changing helicopter characteristics is
very easy.
Real-time graphics applications are tending to get more realistic and approximate real world illumination gets more reasonable due to improvement of graphics hardware. Using a wide variation of algorithms and ideas, graphics processing units (GPU) can simulate complex lighting situations rendering computer generated imagery with complicated effects such as shadows, refraction and reflection of light. Particularly, reflections are an improvement of realism, because they make shiny materials, e.g. brushed metals, wet surfaces like puddles or polished floors, appear more realistic and reveal information of their properties such as roughness and reflectance. Moreover, reflections can get more complex, depending on the view: a wet surface like a street during rain for example will reflect lights depending on the distance of the viewer, resulting in more streaky reflection, which will look more stretched, if the viewer is locatedrnfarther away from the light source. This bachelor thesis aims to give an overview of the state-of-the-art in terms of rendering reflections. Understanding light is a basic need to understand reflections and therefore a physical model of light and its reflection will be covered in section 2, followed by the motivational section 2.2, that will give visual appealing examples for reflections from the real world and the media. Coming to rendering techniques, first, the main principle will be explained in section 3 followed by a short general view of a wide variety of approaches that try to generate correct reflections in section 4. This thesis will describe the implementation of three major algorithms, that produce plausible local reflections. Therefore, the developed framework is described in section 5, then three major algorithms will be covered, that are common methods in most current game and graphics engines: Screen space reflections (SSR), parallax-corrected cube mapping (PCCM) and billboard reflections (BBR). After describing their functional principle, they will be analysed of their visual quality and the possibilities of their real-time application. Finally they will be compared to each other to investigate the advantages and disadvantages over each other. In conclusion, the gained experiences will be described by summarizing advantages and disadvantages of each technique and giving suggestions for improvements. A short perspective will be given, trying to create a view of upcoming real-time rendering techniques for the creation of reflections as specular effects.
VR Fresken
(2018)
Das Projekt VR Fresken setzte sich zum Ziel, mit Hilfe von virtueller Realität im Rahmen einer Museumsausstellung historisch rekonstruierte Räume und deren Deckenfresken interaktiv erlebbar zu machen. In dieser Arbeit werden die eingesetzten Techniken und Technologien beleuchtet, der Anwendungsfall der VR für den Einsatz im Museum untersucht, sowie eine Evaluation der Software im Alltagsbetrieb im Museum durchgeführt.
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.
In order to simulate realistic motion sequences, muscles must be able to be modelled anatomically correct. Yet it is only possible in SimPack to define muscles as a straight line between two points. This thesis presents an approach where ellipses can be defined through which a muscle must pass. The main problem is to calculate the length of this muscle through the ellipses. An algorithm is presented that calculates the shortest path of a muscle path through this ellipses. This algorithm is then implemented in Fortran 90 and integrated into an existing muscle model in SimPack.
Texture-based text detection in digital images using wavelet features and support vector machines
(2010)
In this bachelor thesis a new texture-based approach for the detection of text in digital images is presented. The procedure can be essentially divided into two main tasks, in detection of text blocks and detection of individual words, whereby the individual words are extracted from the detected text blocks. Roughly, the developed method acts with multiple support vector machines, which classify possible text regions of an image into real text regions, using wavelet-based features. In the process the possible text regions are defifined by edge projections with diσerent orientations. The results of the approach are X/Y coordinates, width and height of rectangular regions of an image, which contains individual words. This knowledge can be further processed, for example by an optical character recognition software to get the important and useful text information.
Im Bereich der Computergraphik bilden die Nicht-Photorealistischen Renderingverfahren einen Schwerpunkt in der technischen und wissenschaftlichen Visualisierung, vor allem aber in den künstlerischen Bereichen. Verschiedene Kunststile, sowie Zeichenmaterialien und ihre Eigenschaften stellen unterschiedliche Herausforderungen dar. Eine dieser Herausforderungen ist hierbei die Simulation flüssiger Zeichenmittel.
Diese Arbeit beschäftigt sich mit der Erstellung eines interaktiven Zeichensystems für ein flüssiges Zeichenmittel, der Aquarellmalerei. Für die Simulation wird eine raue Zeichengrundlage generiert, sowie die Fluid Simulation und das optische Farbverhalten der Aquarellmalerei implementiert.
Augmented Reality has many areas of application. It can be used to simplify everyday life as well as working processes. However, since there are
many manufacturers that offer greatly varying systems, choosing the correct system according to application as well as cross-platform development are dfficult. This thesis attempts to develop an application which can be used to simulate Augmented Reality devices on Virtual Reality systems. This should simplify the processes of choosing a system as well as cross-platform
development.
Since the simulation will be designed to run on mobile devices, it should be possible to render high quality, realistic environments in advance, using a panoramic image. On a Virtual Reality device, they need to be displayed as a stereoscopic image. To achieve this, several methods are presented that can be used to perform this conversion. An editor will be created which will allow the creation of scenes, configuration of Augmented Reality devices and displaying them on a Virtual Reality system. For closing this thesis a test will be performed, to check the quality of the simulation as well as improvements that can be made.
This Bachelor thesis describes the conception, implementation and evaluation of a playful augmented reality application for mobile devices. Building on the ARCore SDK, the game pARcours was developed, where the player can place virtual objects in the real environment to build their own parcours. This must be flown through with a likewise virtual aircraft. The main focus in the implementation of the game was on the interaction with the virtual objects and the collision detection of these with real surfaces. Furthermore, various input methods for building the parcours and controlling the aircrafts were examined. In a final evaluation both the game and the various input methods could be evaluated, as well as ARCore with regard to the development of augmented reality applications.
This thesis deals with the development of an authoring system for modeling 3D environments with physical description. In contrast to creating scenes in other common modeling tools, one can now compute and describe physical entities of a scene additional to the usual geometry. It is very important for those authoring systems to be extendable and customizable for specific requirement of the user. The focus lies on developing simple program architecture, which is easy to extend and to modify.
A special challenge of the basic musical education of children is to give them an understanding of reading and writing musical scores. During the training of young choristers it is furthermore important to educate them in directly transforming the written scores into sounds.
Therefore it is an interesting idea to play the sounds to the children via piano or keyboard and simultaneously present them on a screen in musical notation.
The aim of this bachelor thesis is the implementation of such a system that allows to enter scores using a MIDI-compatible keyboard and then depicting these as musical notation. The prototype of the application operates in three steps. It receives the musical scores via keyboard in form of MIDIdatasets. These MIDI-information are converted to the MusicXML-format. Based on this MusicXML-notation the software finally generates and displays the visual output.
This thesis presents two methods for the computation of global illumination. The first is an extension of Reflective Shadow Maps with an additional shadow test in order to handle occlusion. The second method is a novel, bidirectional Light-Injection approach. Rays originating from the light source are traced through the scene and stored inside the shafts of the Linespace datastructure. These shafts are a discretization of the possible spatial directions. The Linespaces are embedded in a Uniform Grid. When retrieving this pre-calculated lightning information no traversal of datastructures and no additional indirection is necessary in the best-case scenario. This reduces computation time and variance compared to Pathtracing. Areas that are mostly lit indirectly and glas profit the most from this. However, the result is only approximative in nature and produces visible artifacts.
Der Markt der mobilen Endgeräte entwickelt sich schnell weiter und es kommen schon Kinder im frühsten Alter mit solchen Technologien in Berührung. Daher ist es wichtig, Kinder richtig an die Geräte heranzuführen. Von Vorteil wäre eine Einbindung von Smartphones und Tablets, im Bezug auf den Lernprozess, in den Unterricht. Die vorliegende Arbeit behandelt deshalb das Konzept einer Lernspielapp, die durch Pädagogen konfiguriert werden kann. Die Evaluation soll Aufschluss über die Motivation der Kinder geben und die Aufgeschlossenheit der Pädagogen gegenüber neuen Medien ermitteln.
Ray Tracing enables a close to reality rendering implementation of a modelled scene. Because of its functioning, it is able to display optical phenomena and complex lighting. Though, numerous computations per pixel have to be done. In practice implementations can not achieve computer graphics" aim of real-time rendering close to 60 frames per second. Current Graphics Processing Units (GPU) allows high execution parallelism of general-purpose computations. By using the graphics-API OpenGL this parallelism can be achieved and it is possible to design and realize a Ray-Tracer, which operates entirely on the GPU. The developed approach will be extended by an Uniform Grid - a Ray-Tracing acceleration structure. Hence, a speed-up is expected.
This thesis` purpose is the implementation of Ray-Tracer, which operates completely on the GPU, and its expansion by integrating an Uniform Grid. Afterwards, the evaluation of maximum achievable performance takes place. Possible problems regarding GPU-programming will be identified and analysed.
This work describes a novel software tool for visualizing anatomical segmentations of medical images. It was developed as part of a bachelor's thesis project, with a view to supporting research into automatic anatomical brain image segmentation. The tool builds on a widely-used visualization approach for 3D image volumes, where sections in orthogonal directions are rendered on screen as 2D images. It implements novel display modes that solve common problems with conventional viewer programs. In particular, it features a double-contour display mode to aid the user's spatial orientation in the image, as well as modes for comparing two competing segmentation labels pertaining to one and the same anatomical region. The tool was developed as an extension to an existing open-source software suite for medical image processing. The visualization modes are, however, suitable for implementation in the context of other viewer programs that follow a similar rendering approach.
The modified code can be found here: soundray.org/mm-segmentation-visualization.tar.gz.
Simulation von Schnee
(2015)
Physic simulations allow the creation of dynamic scenes on the computer. Computer generated images become lively and find use in movies, games and engineering applications. GPGPU techniques make use of the graphics card to simulate physics. The simulation of dynamic snow is still little researched. The Material Point Method is the first technique which is capable of showing the dynamics andrncharacteristics of snow.
The hybrid use of Lagrangian particles and a regular cartesian grid enables solving of partial differential equations. Therefore articles are transformed to the grid. The grid velocities can then be updated with the calculation of gradients in an FEM-manner (finite element method). Finally grid node velocities are weight back to the particles to move them across the scene. This method is coupled with a constitutive model to cover the dynamic nature of snow. This include collisions and breaking.
This bachelor thesis connects the recent developments in GPGPU techniques of OpenGL with the Material Point Method to efficiently simulate visually compelling, dynamic snow scenes.
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.
In den letzten Jahren ist eine steigende Verbreitung von Touchscreen-Geräten zu verzeichnen. Ihre Bedienung unterscheidet sich grundlegend von der mit Maus und Tastatur. Durch die Eingabe mit Gesten oder mehreren Fingern kann es schwierig sein den Aktionen eines Anderen zu folgen. Probleme entstehen durch die Verdeckung des Bildschirms mit der Eingabehand. Sieht man nur den Bildschirminhalt, zum Beispiel bei einer Videoübertragung, gehen Informationen über die Eingabe verloren.
In dieser Arbeit wird ein System entwickelt, das die kollaborative Arbeit an voneinander entfernten Touchscreen-Geräten verbessern soll. Dazu wird aus den Tiefendaten eines Kinect Sensors eine grafische Repräsentation der Eingabehand erstellt. Durch Einblendung dieser Visualisierung soll es einem Anwender erleichtert werden den Eingaben eines Anwenders zu folgen. Bedienkonzepte, wie zum Beispiel Gesten, sollen dadurch besser vermittelt werden. Außerdem soll so die Möglichkeit geschaffen werden, Informationen über eine gemeinsame Problematik effizienter auszutauschen. Deshalb wurde ein Testsystem mit zwei Arbeitsplätzen entwickelt. Darin übernimmt ein Anwender die Rolle des Erklärenden und führt einen zweiten Anwender, den Ausführenden, durch verschiedene Testszenarien. Hierbei stehen ihm bei einem Teil der Aufgaben die Visualisierung der Hand zur Verfügung, während er in anderen Aufgaben nur verbal mit seinem Gegenüber kommunizieren kann.
Im Rahmen einer Evaluation wird das System auf seine Effizienz zur Bedienung von Touchscreen-Systemen überprüft. Des Weiteren wird untersucht, inwieweit die grafische Qualität den gestellten Anforderungen genügt, um einen Mehrwert für die Anwendung zu bieten.
In this thesis we present an approach to track a RGB-D camera in 6DOF andconstruct 3D maps. We first acquire, register and synchronize RGB and depth images. After preprocessing we extract FAST features and match them between two consecutive frames. By depth projection we regain the z-value for the inlier correspondences. Afterwards we estimate the camera motion by 3D point set alignment between the correspondence set using least-squares. This local motion estimate is incrementally applied to a global transformation. Additionally wernpresent methods to build maps based on point cloud data acquired by a RGB-D camera. For map creation we use the OctoMap framework and optionally create a colored point cloud map. The system is evaluated with the widespread RGB-D benchmark.
Raytracing von NURBS
(2019)
NURBS sind eine Art von Splines, die besondere Eigenschaften besitzen.
Das ray tracen von NURBS ist eine der Darstellungsmöglichkeiten von NURBS.
Dies ist durch das konkrete berechnen von Schnittpunkten mit Strahlen
möglich. Durch die vielseitige Möglichkeiten der Modellierung mittels NURBS
sind diese beliebt in Anwendungen die im Maschinenbau verwendet werden
und auch anderen CAD-Programmen. Diese Arbeit befasst sich mit der
Berechnung von NURBS-Kurven und -Oberflächen, dem direkten rendern
von diesen und wägt ab ob sich der Aufwand dafür im Vergleich zu Tesselierung
lohnt.
3D-models are getting more important in many areas such as multimedia applications, robotics or film industries. Of particular interest is the creation of 3D-models from a series of monocular images. This is because the cameras that are required for this purpose are becoming cheaper, smaller and more sophisticated at the same time. Increasingly often, suitable cameras are already integrated in devices like smartphones, tablet PCs or cars for example. Hence, there is a great potential for applications of this reconstruction technique.
This thesis is based on the use of a series of images that were taken with arncalibrated camera. The first step is to extract point correspondences from this image series making use of the well-known SURF- and A-KAZE-features. Starting from the point correspondences, it is possible to reconstruct a 3D-Modell with different algorithms that consists of a point cloud and camera poses. To reduce errors in the 3D-model, this thesis especially focuses on explaining the bundle adjustment algorithm, which is being used for a non-linear error minimization of a cost function.
The thesis also introduces the application for the 3D-reconstruction and the visualization of the results, that was developed in the course of this thesis.
The implemented system is evaluated based on statistics and the newly aquiredrnknowledge is presented. The thesis concludes with a summary of its results, and a number of ideas for potential future applications and developments.
Thematik dieser Arbeit ist das dreidimensionale Image-Warping für diffuse und reflektierende Oberflächen. Das Warpingverfahren für den reflektierenden Fall gibt es erst seit 2014. Bei diesem neuen Algorithmus treten Artefakte auf, sobald ein Bild für einen alternativen Blickwinkel auf eine sehr unebene Fläche berechnet werden soll.
In dieser Arbeit wird der Weg von einem Raytracer, der die Eingabetexturen erzeugt, über das Warpingverfahren für beide Arten der Oberflächen, bis zur Optimierung des Reflective-Warping-Verfahrens erarbeitet. Schließlich werden die Ergebnisse der Optimierung bewertet und in den aktuellen sowie zukünftigen Stand der Technik eingeordnet.
Das Kommunikationsverhalten hat sich in den letzten Jahren durch die Smartphonenutzung verändert. Die Nutzer kommunizieren oft nur noch über den elektronischen Weg. Die persönliche Kommunikation, außerhalb des Smartphones, nimmt ab. Das Umfeld gerät unterdessen in Vergessenheit. In der vorliegenden Arbeit werden verschiedene Spielkonzepte entwickelt, welche die Kommunikation steigern sollen. Realisiert wird der Ansatz in einer prototypischen Stadtführer-App, nach den Spielkonzepten von "Scotland Yard" und "Schnitzeljagd". Während der Nutzung müssen die Spieler verschiedene Aufgaben lösen. Welches Spielkonzept sich in Bezug auf die Kommunikationsförderung am besten eignet, wird in einer Evaluation analysiert.
This thesis deals with the development of an interactive Android card game. As an example, the Hebrew game Yaniv was implemented. Focus is the elaboration of required background components and the corresponding implementation in that application. Required game processes will be screened and a possible solution will be identified.
Die vorliegende Arbeit befasst sich mit der Entwicklung eines Pixel-Sticks, ein digitales Hilfsmittel für das Light Painting. Schwerpunkte sind die Entwicklung von Hard- und Software des Sticks, sowie einer Android Applikation für die Bedienung.
Der Einbezug des Smartphones unterscheidet diesen Pixel-Stick anderen Varianten. Neben der grundlegenden Steuerung ist es möglich, Bilder direkt von dem Smartphone auf den Stick zu übertragen.
In no field of computer science has the hardware developed as rapidly as in the field of computer graphics. Today, we can display complex, geometric scenes in real time in immersive systems and also integrate elaborate simulations.
The aim of this work is to realize the simulation of paint splashes in a virtual world. For this purpose, an application will be implemented with the help of Unity, that uses three different techniques to color the environment with the help of paint splashes. Based on this application, the limits and possibilities of the techniques in virtual environments are examined more closely.
This examination shows that an inverse projection produces the best results.
In this thesis, the theory of video seethrough is fundamentally presented on the basis of a panoramic view from several camera frames of
different perspectives. Based on this, a system was designed and implemented in which video streams are put together into a panoramic image by
perspective distortion. This is then projected onto the inside of a cylinder
with the virtual position of the viewer in the middle. Finally, the resulting
video panoramas will be displayed in VR glasses. Within the implementation some optimizations are also presented, among others those that make
the system real-time capable beyond the task. Furthermore, the developed
system will be evaluated and compared with two other methods.
Molecular dynamics (MD) as a field of molecular modelling has great potential to revolutionize our knowledge and understanding of complex macromolecular structures. Its field of application is huge, reaching from computational chemistry and biology over material sciences to computer-aided drug design. This thesis on one hand provides insights into the underlying physical concepts of molecular dynamics simulations and how they are applied in the MD algorithm, and also briefly illustrates different approaches, as for instance the molecular mechanics and molecular quantum mechanics approaches.
On the other hand an own all-atom MD algorithm is implemented utilizing and simplifying a version of the molecular mechanics based AMBER force field published by \big[\cite{cornell1995second}\big]. This simulation algorithm is then used to show by the example of oxytocin how individual energy terms of a force field function. As a result it has been observed, that applying the bond stretch forces alone caused the molecule to be compacted first in certain regions and then as a whole, and that with adding more energy terms the molecule got to move with increasing flexibility.
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.