Real Time, Accurate, Multi-Featured Rendering of Bump Mapped Surfaces

We present a new technique to render in real time objects which have part of their high frequency geometric detail encoded in bump maps. It is based on the quantization of normal-maps, and achieves excellent result both in rendering time and rendering quality, with respect to other alternative methods. The method proposed also allows to add many interesting visual effects, even for object with large bumb maps, including non-photorealistic rendering, chrome effects, shading under multiple lights, rendering of different materials within a single object, specular reflections and others. Moreover, the implementation of the method is not complex and can be eased by software reuse

Photorealistic physically based render engines: a comparative study

Pérez Roig, F. (2012). Photorealistic physically based render engines: a comparative study. http://hdl.handle.net/10251/14797.Archivo delegad

Enhancing Mesh Deformation Realism: Dynamic Mesostructure Detailing and Procedural Microstructure Synthesis

Propomos uma solução para gerar dados de mapas de relevo dinâmicos para simular deformações em superfícies macias, com foco na pele humana. A solução incorpora a simulação de rugas ao nível mesoestrutural e utiliza texturas procedurais para adicionar detalhes de microestrutura estáticos. Oferece flexibilidade além da pele humana, permitindo a geração de padrões que imitam deformações em outros materiais macios, como couro, durante a animação. As soluções existentes para simular rugas e pistas de deformação frequentemente dependem de hardware especializado, que é dispendioso e de difícil acesso. Além disso, depender exclusivamente de dados capturados limita a direção artística e dificulta a adaptação a mudanças. Em contraste, a solução proposta permite a síntese dinâmica de texturas que se adaptam às deformações subjacentes da malha de forma fisicamente plausível. Vários métodos foram explorados para sintetizar rugas diretamente na geometria, mas sofrem de limitações como auto-interseções e maiores requisitos de armazenamento. A intervenção manual de artistas na criação de mapas de rugas e mapas de tensão permite controle, mas pode ser limitada em deformações complexas ou onde maior realismo seja necessário. O nosso trabalho destaca o potencial dos métodos procedimentais para aprimorar a geração de padrões de deformação dinâmica, incluindo rugas, com maior controle criativo e sem depender de dados capturados. A incorporação de padrões procedimentais estáticos melhora o realismo, e a abordagem pode ser estendida além da pele para outros materiais macios.We propose a solution for generating dynamic heightmap data to simulate deformations for soft surfaces, with a focus on human skin. The solution incorporates mesostructure-level wrinkles and utilizes procedural textures to add static microstructure details. It offers flexibility beyond human skin, enabling the generation of patterns mimicking deformations in other soft materials, such as leater, during animation. Existing solutions for simulating wrinkles and deformation cues often rely on specialized hardware, which is costly and not easily accessible. Moreover, relying solely on captured data limits artistic direction and hinders adaptability to changes. In contrast, our proposed solution provides dynamic texture synthesis that adapts to underlying mesh deformations. Various methods have been explored to synthesize wrinkles directly to the geometry, but they suffer from limitations such as self-intersections and increased storage requirements. Manual intervention by artists using wrinkle maps and tension maps provides control but may be limited to the physics-based simulations. Our research presents the potential of procedural methods to enhance the generation of dynamic deformation patterns, including wrinkles, with greater creative control and without reliance on captured data. Incorporating static procedural patterns improves realism, and the approach can be extended to other soft-materials beyond skin

Hybrid Rugosity Mesostructures (HRMs) for fast and accurate rendering of fine haptic detail

The haptic rendering of surface mesostructure (fine relief features) in dense triangle meshes requires special structures, equipment, and high sampling rates for detailed perception of rugged models. Low cost approaches render haptic texture at the expense of fidelity of perception. We propose a faster method for surface haptic rendering using image-based Hybrid Rugosity Mesostructures (HRMs), paired maps with per-face heightfield displacements and normal maps, which are layered on top of a much decimated mesh, effectively adding greater surface detail than actually present in the geometry. The haptic probe’s force response algorithm is modulated using the blended HRM coat to render dense surface features at much lower costs. The proposed method solves typical problems at edge crossings, concave foldings and texture transitions. To prove the wellness of the approach, a usability testbed framework was built to measure and compare experimental results of haptic rendering approaches in a common set of specially devised meshes, HRMs, and performance tests. Trial results of user testing evaluations show the goodness of the proposed HRM technique, rendering accurate 3D surface detail at high sampling rates, deriving useful modeling and perception thresholds for this technique.Peer ReviewedPostprint (published version

Exploration of Mouth Shading and Lighting in CG Production

The lighting and shading of human teeth in current computer animation features and live-action movies with effects are often intentionally avoided or processed by simple methods since they interact with light in complex ways through their intricate layered structure. The semi-translucent appearance of natural human teeth which result from subsurface scattering is difficult to replicate in synthetic scenes, though two techniques are often implemented. The first technique is to create an anatomically correct layered model, and render the teeth with both theoretically and empirically derived optical parameters of human teeth using physical subsurface materials. The second technique largely takes advantage of visual cheating, achieved by irradiance blending of finely painted textures. The result visually confirms that for most situations, non-physically based shading can yield believable rendered teeth by finely controlling contribution layers. In particular situations, such as an extremely close shot of a mouth, however, a physically correct shading model is necessary to produce highly translucent and realistic teeth

Shader Programming: An Introduction Using the Effect Framework

Current commodity graphics cards offer programmability through vertex shaders and pixel shaders to create special effects by deformation, lighting, texturing, etc. The Effect framework introduced by Microsoft allows to store shader program code, settings, and a limited graphical user interface within a single .fx text file. This supports a division of labor between programmers writing the code and designers using the GUI elements to control settings. Furthermore, the Effect framework proves to be ideal for experimenting with shader programming — be it for learning purposes or for rapid prototyping. In this tutorial, we employ the Effect framework for an exploratory, hands-on approach, introducing first principles only as needed, not in advance. Simple shader programs are used to review basic 3D techniques such as homogeneous coordinates and the Phong shading model. Then we turn to basic deformation effects employing vertex shaders and the use of texture maps as decals or reflected environments inside pixel shaders. To create bump mapping and related effects, tangent space coordinates and normal maps are introduced. Finally, we treat more complex effects such as anisotropic specular highlights. Keywords: Pixel shader, Vertex shader, HLSL, Effect framewor

Artist-Oriented Surfacing Workflow

Surfacing is the art of creating materials for digital objects, and it is an incredible technical and artistic challenge. Creating materials and textures for 3D meshes involves managing potentially hundreds of image files, moving data between multiple software packages, and building shaders that will work consistently through a digital production hierarchy. All while attempting to create a piece of art that will tell a story of what an object is, how it was made, and where it has been. Balancing these technical and artistic components is an extraordinary challenge, and it is easy for an artist to get overwhelmed or distracted by the technical demands of surfacing at the cost of the quality of their art. The topic of this thesis is a suite of tools designed to allow artists to intuitively manage these technical demands by streamlining the most time-consuming aspects of surfacing into condensed one-click operations

vorgelegt von

Prof. Dr. N. NavabTo my familyAcknowledgements I am deeply grateful that I had the opportunity to write this thesis while working at the Chair for Pattern Recognition within the project B6 of the Sonderforschungsbereich 603 (funded by Deutsche Forschungsgemeinschaft). Many people contributed to this work and I want to express my gratitude to all of them