114 research outputs found

    Automatic 3D facial model and texture reconstruction from range scans

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    This paper presents a fully automatic approach to fitting a generic facial model to detailed range scans of human faces to reconstruct 3D facial models and textures with no manual intervention (such as specifying landmarks). A Scaling Iterative Closest Points (SICP) algorithm is introduced to compute the optimal rigid registrations between the generic model and the range scans with different sizes. And then a new template-fitting method, formulated in an optmization framework of minimizing the physically based elastic energy derived from thin shells, faithfully reconstructs the surfaces and the textures from the range scans and yields dense point correspondences across the reconstructed facial models. Finally, we demonstrate a facial expression transfer method to clone facial expressions from the generic model onto the reconstructed facial models by using the deformation transfer technique

    Влияние магнитомеханического резонанса на амплитудно- и фазочастотные зависимости переменных составляющих эффекта Фарадея

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    В рамках модели продольных колебаний тонкого стержня из магнитооптического кристалла в условиях магнитомеханического резонанса показано, что вынужденные колебания могут создавать не только амплитудные, но и фазочастотные зависимости переменных составляющих эффекта Фарадея.У рамках моделі поздовжніх коливань тонкого стрижня із магнітооптичного кристала в умовах магнітомеханічного резонансу показано, що вимушені коливання можуть створювати не тільки амплітудні, але й фазочастотні залежності змінних складових ефекту Фарадея.In the framework of a model of longitudinal vibrations of a thin rod fabricated of the magneto-optical crystal under a magnetomechanical resonance, it is shown that the forced oscillations can create not only the amplitude but also phase-frequency dependences of the variable components of the Faraday effect

    Fast character modeling with sketch-based PDE surfaces

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    © 2020, The Author(s). Virtual characters are 3D geometric models of characters. They have a lot of applications in multimedia. In this paper, we propose a new physics-based deformation method and efficient character modelling framework for creation of detailed 3D virtual character models. Our proposed physics-based deformation method uses PDE surfaces. Here PDE is the abbreviation of Partial Differential Equation, and PDE surfaces are defined as sculpting force-driven shape representations of interpolation surfaces. Interpolation surfaces are obtained by interpolating key cross-section profile curves and the sculpting force-driven shape representation uses an analytical solution to a vector-valued partial differential equation involving sculpting forces to quickly obtain deformed shapes. Our proposed character modelling framework consists of global modeling and local modeling. The global modeling is also called model building, which is a process of creating a whole character model quickly with sketch-guided and template-based modeling techniques. The local modeling produces local details efficiently to improve the realism of the created character model with four shape manipulation techniques. The sketch-guided global modeling generates a character model from three different levels of sketched profile curves called primary, secondary and key cross-section curves in three orthographic views. The template-based global modeling obtains a new character model by deforming a template model to match the three different levels of profile curves. Four shape manipulation techniques for local modeling are investigated and integrated into the new modelling framework. They include: partial differential equation-based shape manipulation, generalized elliptic curve-driven shape manipulation, sketch assisted shape manipulation, and template-based shape manipulation. These new local modeling techniques have both global and local shape control functions and are efficient in local shape manipulation. The final character models are represented with a collection of surfaces, which are modeled with two types of geometric entities: generalized elliptic curves (GECs) and partial differential equation-based surfaces. Our experiments indicate that the proposed modeling approach can build detailed and realistic character models easily and quickly

    Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

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    9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

    Abstract GPU-Based Ray-Casting of Quadratic Surfaces

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    Quadratic surfaces are frequently used primitives in geometric modeling and scientific visualization, such as rendering of tensor fields, particles, and molecular structures. While high visual quality can be achieved using sophisticated ray tracing techniques, interactive applications typically use either coarsely tessellated polygonal approximations or pre-rendered depth sprites, thereby trading off visual quality and perspective correctness for higher rendering performance. In contrast, we propose an efficient rendering technique for quadric primitives based on GPU-accelerated splatting. While providing similar performance as point-sprites, our methods provides perspective correctness and superior visual quality using per-pixel ray-casting. 1
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