952 research outputs found

    Spacial Groom

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    This thesis describes a method for grooming computer generated fur in a 3D production environment. Fur grooming systems that are included with the major commercial 3D software packages link fur grooms to a specific model's topology. This significantly reduces the flexibility to continue development of a model's surface edges, loops, and vertices after fur grooming has started. By using a method that links the groom to the 3D environment rather than the model itself, a groom can be transferred between meshes. This provides increased artistic flexibility within a production pipeline for both modeling and fur grooming

    An investigation of hair modelling and rendering techniques with emphasis on African hairstyles

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    Many computer graphics applications make use of virtual humans. Methods for modelling and rendering hair are needed so that hairstyles can be added to the virtual humans. Modelling and rendering hair is challenging due to the large number of hair strands and their geometric properties, the complex lighting effects that occur among the strands of hair, and the complexity and large variation of human hairstyles. While methods have been developed for generating hair, no methods exist for generating African hair, which differs from hair of other ethnic groups. This thesis presents methods for modelling and rendering African hair. Existing hair modelling and rendering techniques are investigated, and the knowledge gained from the investigation is used to develop or enhance hair modelling and rendering techniques to produce three different forms of hair commonly found in African hairstyles. The different forms of hair identified are natural curly hair, straightened hair, and braids or twists of hair. The hair modelling techniques developed are implemented as plug-ins for the graphics program LightWave 3D. The plug-ins developed not only model the three identified forms of hair, but also add the modelled hair to a model of a head, and can be used to create a variety of African hairstyles. The plug-ins significantly reduce the time spent on hair modelling. Tests performed show that increasing the number of polygons used to model hair increases the quality of the hair produced, but also increases the rendering time. However, there is usually an upper bound to the number of polygons needed to produce a reasonable hairstyle, making it feasible to add African hairstyles to virtual humans. The rendering aspects investigated include hair illumination, texturing, shadowing and antialiasing. An anisotropic illumination model is developed that considers the properties of African hair, including the colouring, opacity and narrow width of the hair strands. Texturing is used in several instances to create the effect of individual strands of hair. Results show that texturing is useful for representing many hair strands because the density of the hair in a texture map does not have an effect on the rendering time. The importance of including a shadowing technique and applying an anti-aliasing method when rendering hair is demonstrated. The rendering techniques are implemented using the RenderMan Interface and Shading Language. A number of complete African hairstyles are shown, demonstrating that the techniques can be used to model and render African hair successfully.GNU Ghostscript 7.0

    Towards Predictive Rendering in Virtual Reality

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    The strive for generating predictive images, i.e., images representing radiometrically correct renditions of reality, has been a longstanding problem in computer graphics. The exactness of such images is extremely important for Virtual Reality applications like Virtual Prototyping, where users need to make decisions impacting large investments based on the simulated images. Unfortunately, generation of predictive imagery is still an unsolved problem due to manifold reasons, especially if real-time restrictions apply. First, existing scenes used for rendering are not modeled accurately enough to create predictive images. Second, even with huge computational efforts existing rendering algorithms are not able to produce radiometrically correct images. Third, current display devices need to convert rendered images into some low-dimensional color space, which prohibits display of radiometrically correct images. Overcoming these limitations is the focus of current state-of-the-art research. This thesis also contributes to this task. First, it briefly introduces the necessary background and identifies the steps required for real-time predictive image generation. Then, existing techniques targeting these steps are presented and their limitations are pointed out. To solve some of the remaining problems, novel techniques are proposed. They cover various steps in the predictive image generation process, ranging from accurate scene modeling over efficient data representation to high-quality, real-time rendering. A special focus of this thesis lays on real-time generation of predictive images using bidirectional texture functions (BTFs), i.e., very accurate representations for spatially varying surface materials. The techniques proposed by this thesis enable efficient handling of BTFs by compressing the huge amount of data contained in this material representation, applying them to geometric surfaces using texture and BTF synthesis techniques, and rendering BTF covered objects in real-time. Further approaches proposed in this thesis target inclusion of real-time global illumination effects or more efficient rendering using novel level-of-detail representations for geometric objects. Finally, this thesis assesses the rendering quality achievable with BTF materials, indicating a significant increase in realism but also confirming the remainder of problems to be solved to achieve truly predictive image generation

    Realistic Visualization of Animated Virtual Cloth

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    Photo-realistic rendering of real-world objects is a broad research area with applications in various different areas, such as computer generated films, entertainment, e-commerce and so on. Within photo-realistic rendering, the rendering of cloth is a subarea which involves many important aspects, ranging from material surface reflection properties and macroscopic self-shadowing to animation sequence generation and compression. In this thesis, besides an introduction to the topic plus a broad overview of related work, different methods to handle major aspects of cloth rendering are described. Material surface reflection properties play an important part to reproduce the look & feel of materials, that is, to identify a material only by looking at it. The BTF (bidirectional texture function), as a function of viewing and illumination direction, is an appropriate representation of reflection properties. It captures effects caused by the mesostructure of a surface, like roughness, self-shadowing, occlusion, inter-reflections, subsurface scattering and color bleeding. Unfortunately a BTF data set of a material consists of hundreds to thousands of images, which exceeds current memory size of personal computers by far. This work describes the first usable method to efficiently compress and decompress a BTF data for rendering at interactive to real-time frame rates. It is based on PCA (principal component analysis) of the BTF data set. While preserving the important visual aspects of the BTF, the achieved compression rates allow the storage of several different data sets in main memory of consumer hardware, while maintaining a high rendering quality. Correct handling of complex illumination conditions plays another key role for the realistic appearance of cloth. Therefore, an upgrade of the BTF compression and rendering algorithm is described, which allows the support of distant direct HDR (high-dynamic-range) illumination stored in environment maps. To further enhance the appearance, macroscopic self-shadowing has to be taken into account. For the visualization of folds and the life-like 3D impression, these kind of shadows are absolutely necessary. This work describes two methods to compute these shadows. The first is seamlessly integrated into the illumination part of the rendering algorithm and optimized for static meshes. Furthermore, another method is proposed, which allows the handling of dynamic objects. It uses hardware-accelerated occlusion queries for the visibility determination. In contrast to other algorithms, the presented algorithm, despite its simplicity, is fast and produces less artifacts than other methods. As a plus, it incorporates changeable distant direct high-dynamic-range illumination. The human perception system is the main target of any computer graphics application and can also be treated as part of the rendering pipeline. Therefore, optimization of the rendering itself can be achieved by analyzing human perception of certain visual aspects in the image. As a part of this thesis, an experiment is introduced that evaluates human shadow perception to speedup shadow rendering and provides optimization approaches. Another subarea of cloth visualization in computer graphics is the animation of the cloth and avatars for presentations. This work also describes two new methods for automatic generation and compression of animation sequences. The first method to generate completely new, customizable animation sequences, is based on the concept of finding similarities in animation frames of a given basis sequence. Identifying these similarities allows jumps within the basis sequence to generate endless new sequences. Transmission of any animated 3D data over bandwidth-limited channels, like extended networks or to less powerful clients requires efficient compression schemes. The second method included in this thesis in the animation field is a geometry data compression scheme. Similar to the BTF compression, it uses PCA in combination with clustering algorithms to segment similar moving parts of the animated objects to achieve high compression rates in combination with a very exact reconstruction quality.Realistische Visualisierung von animierter virtueller Kleidung Das photorealistisches Rendering realer Gegenstände ist ein weites Forschungsfeld und hat Anwendungen in vielen Bereichen. Dazu zählen Computer generierte Filme (CGI), die Unterhaltungsindustrie und E-Commerce. Innerhalb dieses Forschungsbereiches ist das Rendern von photorealistischer Kleidung ein wichtiger Bestandteil. Hier reichen die wichtigen Aspekte, die es zu berücksichtigen gilt, von optischen Materialeigenschaften über makroskopische Selbstabschattung bis zur Animationsgenerierung und -kompression. In dieser Arbeit wird, neben der Einführung in das Thema, ein weiter Überblick über ähnlich gelagerte Arbeiten gegeben. Der Schwerpunkt der Arbeit liegt auf den wichtigen Aspekten der virtuellen Kleidungsvisualisierung, die oben beschrieben wurden. Die optischen Reflektionseigenschaften von Materialoberflächen spielen eine wichtige Rolle, um das so genannte look & feel von Materialien zu charakterisieren. Hierbei kann ein Material vom Nutzer identifiziert werden, ohne dass er es direkt anfassen muss. Die BTF (bidirektionale Texturfunktion)ist eine Funktion die abhängig von der Blick- und Beleuchtungsrichtung ist. Daher ist sie eine angemessene Repräsentation von Reflektionseigenschaften. Sie enthält Effekte wie Rauheit, Selbstabschattungen, Verdeckungen, Interreflektionen, Streuung und Farbbluten, die durch die Mesostruktur der Oberfläche hervorgerufen werden. Leider besteht ein BTF Datensatz eines Materials aus hunderten oder tausenden von Bildern und sprengt damit herkömmliche Hauptspeicher in Computern bei weitem. Diese Arbeit beschreibt die erste praktikable Methode, um BTF Daten effizient zu komprimieren, zu speichern und für Echtzeitanwendungen zum Visualisieren wieder zu dekomprimieren. Die Methode basiert auf der Principal Component Analysis (PCA), die Daten nach Signifikanz ordnet. Während die PCA die entscheidenen visuellen Aspekte der BTF erhält, können mit ihrer Hilfe Kompressionsraten erzielt werden, die es erlauben mehrere BTF Materialien im Hauptspeicher eines Consumer PC zu verwalten. Dies erlaubt ein High-Quality Rendering. Korrektes Verwenden von komplexen Beleuchtungssituationen spielt eine weitere, wichtige Rolle, um Kleidung realistisch erscheinen zu lassen. Daher wird zudem eine Erweiterung des BTF Kompressions- und Renderingalgorithmuses erläutert, die den Einsatz von High-Dynamic Range (HDR) Beleuchtung erlaubt, die in environment maps gespeichert wird. Um die realistische Erscheinung der Kleidung weiter zu unterstützen, muss die makroskopische Selbstabschattung integriert werden. Für die Visualisierung von Falten und den lebensechten 3D Eindruck ist diese Art von Schatten absolut notwendig. Diese Arbeit beschreibt daher auch zwei Methoden, diese Schatten schnell und effizient zu berechnen. Die erste ist nahtlos in den Beleuchtungspart des obigen BTF Renderingalgorithmuses integriert und für statische Geometrien optimiert. Die zweite Methode behandelt dynamische Objekte. Dazu werden hardwarebeschleunigte Occlusion Queries verwendet, um die Sichtbarkeitsberechnung durchzuführen. Diese Methode ist einerseits simpel und leicht zu implementieren, anderseits ist sie schnell und produziert weniger Artefakte, als vergleichbare Methoden. Zusätzlich ist die Verwendung von veränderbarer, entfernter HDR Beleuchtung integriert. Das menschliche Wahrnehmungssystem ist das eigentliche Ziel jeglicher Anwendung in der Computergrafik und kann daher selbst als Teil einer erweiterten Rendering Pipeline gesehen werden. Daher kann das Rendering selbst optimiert werden, wenn man die menschliche Wahrnehmung verschiedener visueller Aspekte der berechneten Bilder analysiert. Teil der vorliegenden Arbeit ist die Beschreibung eines Experimentes, das menschliche Schattenwahrnehmung untersucht, um das Rendern der Schatten zu beschleunigen. Ein weiteres Teilgebiet der Kleidungsvisualisierung in der Computergrafik ist die Animation der Kleidung und von Avataren für Präsentationen. Diese Arbeit beschreibt zwei neue Methoden auf diesem Teilgebiet. Einmal ein Algorithmus, der für die automatische Generierung neuer Animationssequenzen verwendet werden kann und zum anderen einen Kompressionsalgorithmus für eben diese Sequenzen. Die automatische Generierung von völlig neuen, anpassbaren Animationen basiert auf dem Konzept der Ähnlichkeitssuche. Hierbei werden die einzelnen Schritte von gegebenen Basisanimationen auf Ähnlichkeiten hin untersucht, die zum Beispiel die Geschwindigkeiten einzelner Objektteile sein können. Die Identifizierung dieser Ähnlichkeiten erlaubt dann Sprünge innerhalb der Basissequenz, die dazu benutzt werden können, endlose, neue Sequenzen zu erzeugen. Die Übertragung von animierten 3D Daten über bandbreitenlimitierte Kanäle wie ausgedehnte Netzwerke, Mobilfunk oder zu sogenannten thin clients erfordert eine effiziente Komprimierung. Die zweite, in dieser Arbeit vorgestellte Methode, ist ein Kompressionsschema für Geometriedaten. Ähnlich wie bei der Kompression von BTF Daten wird die PCA in Verbindung mit Clustering benutzt, um die animierte Geometrie zu analysieren und in sich ähnlich bewegende Teile zu segmentieren. Diese erkannten Segmente lassen sich dann hoch komprimieren. Der Algorithmus arbeitet automatisch und erlaubt zudem eine sehr exakte Rekonstruktionsqualität nach der Dekomprimierung

    Hardware-supported cloth rendering

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    Many computer graphics applications involve rendering humans and their natural surroundings, which inevitably requires displaying textiles. To accurately resemble the appearance of e.g. clothing or furniture, reflection models are needed which are capable of modeling the highly complex reflection effects exhibited by textiles. This thesis focuses on generating realistic high quality images of textiles by developing suitable reflection models and introducing algorithms for illumination computation of cloth surfaces. As efficiency is essential for illumination computation, we additionally place great importance on exploiting graphics hardware to achieve high frame rates. To this end, we present a variety of hardware-accelerated methods to compute the illumination in textile micro geometry. We begin by showing how indirect illumination and shadows can be efficiently accounted for in heightfields, parametric surfaces, and triangle meshes. Using these methods, we can considerably speed up the computation of data structures like tabular bidirectional reflectance distribution functions (BRDFs) and bidirectional texture functions (BTFs), and also efficiently illuminate heightfield geometry and bump maps. Furthermore, we develop two shading models, which account for all important reflection properties exhibited by textiles. While the first model is suited for rendering textiles with general micro geometry, the second, based on volumetric textures, is specially tailored for rendering knitwear. To apply the second model e.g. to the triangle mesh of a garment, we finally introduce a new rendering algorithm for displaying semi-transparent volumetric textures at high interactive rates.Eine Vielzahl von Anwendungen in der Computergraphik schließen auch die Darstellung von Menschen und deren natürlicher Umgebung ein, was zwangsläufig auch die Darstellung von Textilien erfordert. Um beispielsweise das Aussehen von Bekleidung oder Möbeln genau zu erfassen, werden Reflexionsmodelle benötigt, die in der Lage sind, die hochkomplexen Reflexionseffekte von Textilien zu berücksichtigen. Der Schwerpunkt dieser Dissertation liegt in der Generierung qualitativ hochwertiger Bilder von Textilien, was wir durch die Entwicklung geeigneter Reflexionsmodelle und von Algorithmen zur Beleuchtungsberechnung an Stoffoberflächen ermöglichen. Da Effizienz essentiell für die Beleuchtungsberechnung ist, nutzen wir die Möglichkeiten von Graphikhardware aus, um hohe Bildwiederholraten zu erzielen. Hierfür legen wir eine Vielzahl von hardware-beschleunigten Methoden zur Beleuchtungsberechnung der Mikrogeometrie von Textilien vor. Zuerst zeigen wir, wie indirekte Beleuchtung und Schatten effizient in Höhenfeldern, parametrischen Flächen und Dreiecksnetzen berücksichtigt werden können. Mit Hilfe dieser Methoden kann die Berechnung von Datenstrukturen wie tabellarischer bidirectional reflectance distribution functions (BRDFs) und bidirectional texture functions (BTFs) erheblich beschleunigt, sowie die Beleuchtung von Höhenfeld-Geometrie und Bumpmaps effizient errechnet werden.Weiterhin entwickeln wir zwei Reflexionsmodelle, welche alle wichtigen Reflexionseigenschaften berücksichtigen, die Textilien aufweisen. Während das erste Modell sich zur Darstellung von Textilien mit allgemeiner Mikrogeometrie eignet, ist das zweite, welches auf volumetrischen Texturen basiert, speziell auf die Darstellung von Strickwaren zugeschnitten. Um das zweite Modell z.B. auf das Dreiecksnetz eines Bekleidungsstückes anzuwenden führen wir einen neuen Renderingalgorithmus für die Darstellung von semi-transparenten volumetrischen Texturen mit hohen Bildwiederholraten ein

    3D Shape Modeling Using High Level Descriptors

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    Visual Aesthetics in Digital Games: A Comparative Analysis Between Photorealism and Stylized Graphicsgraphics

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    This dissertation starts from the assumption that every digital game has some kind of visual display. Based on that, it investigates photorealistic and stylized graphics, two popular visual styles in digital games, in order to comprehend the process of creating a prototype that incorporates those styles, as well as the technological artistic challenges of implementing each style in a solo development scenario, with the goal of assisting in the practice of designing this type of content. A literature review on digital game appearance and the development of both photorealistic and stylized styles was conducted to ground the development of a prototype. The result of the prototype creation is documented, so its findings can lead to the expansion of knowledge that can be used in practice and can inform practitioners and other designers

    Serious games: design and development

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    With the growth of the video game industry, interest in video game research has increased, leading to the study of Serious Games. Serious Games are generally perceived as games that use the video games’ capabilities to emerge players, for other purposes besides entertainment. These purposes include education and training, among others. By using Serious Games for education, teachers could capture the students’ attention in the same way that video games often do, thus the learning process could be more efficient. Additionally, by exploiting the potential of these virtual worlds, it is possible to experience situations that would otherwise be very difficult to experience in the real world, mainly due to reasons of cost, safety and time. Serious Games research and development is still very scarse. However, nowadays there is a large number of available platforms and tools, which can be used to develop Serious Games and video games in general. For instance, web browsers can now provide easy access to realistic 3D virtual worlds. This grants video game developers the tools to create compelling and rich environments that can be accessed by anyone with an internet connection. Additionnaly, other development platforms can be used to achieve different goals. Desktop technologies provide greater processing power and achieve greater results in terms of visual quality, as well as in terms of creating more accurate simulations. This disseration describes the design and development of two Serious Games, one for PC, developed with XNA, and another for the web, developed with WebGL.O crescimento da indústria dos jogos de vídeo, despoletou um maior interesse no estudo deste fenómeno, o que consequentemente levou ao estudo de Jogos Sérios. Jogos Sérios são normalmente considerados jogos de vídeo que são desenvolvidos para outros fins para além do entretenimento. Estes fins incluem a educação e o treino, entre outros. Ao utilizar Jogos Sérios para a educação, os docentes poderiam conseguir captar a atenção dos alunos da mesma forma que os jogos de vídeo normalmente conseguem. Desta forma o processo de aprendizagem poderia ser mais eficiente. Adicionalmente, ao explorar o potencial destes mundos virtuais, é possível experienciar situações que de outra forma seriam difíceis de experienciar na vida real, devido ao seu custo, a razões de segurança e também ao tempo dispendido para as realizar. O estudo de Jogos Sérios é ainda bastante disperso. No entanto, hoje em dia existe já um grande número de plataformas e ferramentas disponíveis que podem ser usadas para desenvolver Jogos Sérios. Por exemplo, os web browsers podem agora fornecer acesso fácil a mundos virtuais 3D. Isto permite que os criadores de jogos de vídeo tenham acesso às ferramentas necessárias para criar ambientes ricos, que possam ser acedidos por qualquer pessoa através de uma ligacção à internet. Adicionalmente, existem outras plataformas de desenvolvimento que podem ser utilizadas para alcançar objetivos diferentes. Tecnologias desktop fornecem um maior poder de processamento e permitem alcançar melhores resultados em termos de qualidade visual, bem como em termos de criação de simulações mais precisas. Nesta dissertação descreve-se a criação e o desenvolvimento de dois Jogos Sérios, um para PC, desenvolvido em XNA e outro outro para a web, desenvolvido em WebGL

    Realistic reconstruction and rendering of detailed 3D scenarios from multiple data sources

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    During the last years, we have witnessed significant improvements in digital terrain modeling, mainly through photogrammetric techniques based on satellite and aerial photography, as well as laser scanning. These techniques allow the creation of Digital Elevation Models (DEM) and Digital Surface Models (DSM) that can be streamed over the network and explored through virtual globe applications like Google Earth or NASA WorldWind. The resolution of these 3D scenes has improved noticeably in the last years, reaching in some urban areas resolutions up to 1m or less for DEM and buildings, and less than 10 cm per pixel in the associated aerial imagery. However, in rural, forest or mountainous areas, the typical resolution for elevation datasets ranges between 5 and 30 meters, and typical resolution of corresponding aerial photographs ranges between 25 cm to 1 m. This current level of detail is only sufficient for aerial points of view, but as the viewpoint approaches the surface the terrain loses its realistic appearance. One approach to augment the detail on top of currently available datasets is adding synthetic details in a plausible manner, i.e. including elements that match the features perceived in the aerial view. By combining the real dataset with the instancing of models on the terrain and other procedural detail techniques, the effective resolution can potentially become arbitrary. There are several applications that do not need an exact reproduction of the real elements but would greatly benefit from plausibly enhanced terrain models: videogames and entertainment applications, visual impact assessment (e.g. how a new ski resort would look), virtual tourism, simulations, etc. In this thesis we propose new methods and tools to help the reconstruction and synthesis of high-resolution terrain scenes from currently available data sources, in order to achieve realistically looking ground-level views. In particular, we decided to focus on rural scenarios, mountains and forest areas. Our main goal is the combination of plausible synthetic elements and procedural detail with publicly available real data to create detailed 3D scenes from existing locations. Our research has focused on the following contributions: - An efficient pipeline for aerial imagery segmentation - Plausible terrain enhancement from high-resolution examples - Super-resolution of DEM by transferring details from the aerial photograph - Synthesis of arbitrary tree picture variations from a reduced set of photographs - Reconstruction of 3D tree models from a single image - A compact and efficient tree representation for real-time rendering of forest landscapesDurant els darrers anys, hem presenciat avenços significatius en el modelat digital de terrenys, principalment gràcies a tècniques fotogramètriques, basades en fotografia aèria o satèl·lit, i a escàners làser. Aquestes tècniques permeten crear Models Digitals d'Elevacions (DEM) i Models Digitals de Superfícies (DSM) que es poden retransmetre per la xarxa i ser explorats mitjançant aplicacions de globus virtuals com ara Google Earth o NASA WorldWind. La resolució d'aquestes escenes 3D ha millorat considerablement durant els darrers anys, arribant a algunes àrees urbanes a resolucions d'un metre o menys per al DEM i edificis, i fins a menys de 10 cm per píxel a les fotografies aèries associades. No obstant, en entorns rurals, boscos i zones muntanyoses, la resolució típica per a dades d'elevació es troba entre 5 i 30 metres, i per a les corresponents fotografies aèries varia entre 25 cm i 1m. Aquest nivell de detall només és suficient per a punts de vista aeris, però a mesura que ens apropem a la superfície el terreny perd tot el realisme. Una manera d'augmentar el detall dels conjunts de dades actuals és afegint a l'escena detalls sintètics de manera plausible, és a dir, incloure elements que encaixin amb les característiques que es perceben a la vista aèria. Així, combinant les dades reals amb instàncies de models sobre el terreny i altres tècniques de detall procedural, la resolució efectiva del model pot arribar a ser arbitrària. Hi ha diverses aplicacions per a les quals no cal una reproducció exacta dels elements reals, però que es beneficiarien de models de terreny augmentats de manera plausible: videojocs i aplicacions d'entreteniment, avaluació de l'impacte visual (per exemple, com es veuria una nova estació d'esquí), turisme virtual, simulacions, etc. En aquesta tesi, proposem nous mètodes i eines per ajudar a la reconstrucció i síntesi de terrenys en alta resolució partint de conjunts de dades disponibles públicament, per tal d'aconseguir vistes a nivell de terra realistes. En particular, hem decidit centrar-nos en escenes rurals, muntanyes i àrees boscoses. El nostre principal objectiu és la combinació d'elements sintètics plausibles i detall procedural amb dades reals disponibles públicament per tal de generar escenes 3D d'ubicacions existents. La nostra recerca s'ha centrat en les següents contribucions: - Un pipeline eficient per a segmentació d'imatges aèries - Millora plausible de models de terreny a partir d'exemples d’alta resolució - Super-resolució de models d'elevacions transferint-hi detalls de la fotografia aèria - Síntesis d'un nombre arbitrari de variacions d’imatges d’arbres a partir d'un conjunt reduït de fotografies - Reconstrucció de models 3D d'arbres a partir d'una única fotografia - Una representació compacta i eficient d'arbres per a navegació en temps real d'escenesPostprint (published version

    Capturing and Reconstructing the Appearance of Complex {3D} Scenes

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    In this thesis, we present our research on new acquisition methods for reflectance properties of real-world objects. Specifically, we first show a method for acquiring spatially varying densities in volumes of translucent, gaseous material with just a single image. This makes the method applicable to constantly changing phenomena like smoke without the use of high-speed camera equipment. Furthermore, we investigated how two well known techniques -- synthetic aperture confocal imaging and algorithmic descattering -- can be combined to help looking through a translucent medium like fog or murky water. We show that the depth at which we can still see an object embedded in the scattering medium is increased. In a related publication, we show how polarization and descattering based on phase-shifting can be combined for efficient 3D~scanning of translucent objects. Normally, subsurface scattering hinders the range estimation by offsetting the peak intensity beneath the surface away from the point of incidence. With our method, the subsurface scattering is reduced to a minimum and therefore reliable 3D~scanning is made possible. Finally, we present a system which recovers surface geometry, reflectance properties of opaque objects, and prevailing lighting conditions at the time of image capture from just a small number of input photographs. While there exist previous approaches to recover reflectance properties, our system is the first to work on images taken under almost arbitrary, changing lighting conditions. This enables us to use images we took from a community photo collection website
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