The need to analyze and visualize distances between objects arises in many use cases. Although the problem to calculate the distance between two polygonal objects may sound simple, real-world scenarios with large mode...
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ISBN:
(纸本)9781538673157
The need to analyze and visualize distances between objects arises in many use cases. Although the problem to calculate the distance between two polygonal objects may sound simple, real-world scenarios with large models will always be challenging, but optimization techniques such as space partitioning can reduce the complexity of the average case significantly. Our contribution to this problem is a publicly available benchmark to compare distance calculation algorithms. Furthermore, we evaluated the two most important techniques (hierarchical tree structures versus grid-based approaches).
Procedural modeling is a technique to describe 3D objects by a constructive, generative description. In order to tap the full potential of this technique the content creator needs to be familiar with two worlds - proc...
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ISBN:
(纸本)9788086943862
Procedural modeling is a technique to describe 3D objects by a constructive, generative description. In order to tap the full potential of this technique the content creator needs to be familiar with two worlds - procedural modeling techniques and computer graphics on the one hand as well as domain-specific expertise and specialized knowledge on the other hand. This article presents a Java Script-based approach to combine both worlds. It describes a modeling tool for generative modeling whose target audience consists of beginners and intermediate learners of procedural modeling techniques. Our approach will be beneficial in various contexts. Java Script is a wide-spread, easy-to-use language. With our tool procedural models can be translated from Java Script to various generative modeling and rendering systems.
During the last ten years a number of interface specifications for the exchange of product model data between CAD systems as well as between CAD and other computer aided systems have been developed. Some of them are a...
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ISBN:
(纸本)0444814965
During the last ten years a number of interface specifications for the exchange of product model data between CAD systems as well as between CAD and other computer aided systems have been developed. Some of them are also standardized by national or international bodies. The capabilities of these interface specifications are different and cover various application areas, data formats and file format definitions. This article is focusing on freeform surfaces which are described and exchanged using standard interfaces. A general overview on different mathematical representations of freeform surfaces, the specification and application of freeform surfaces within standard interfaces, and a new methodology for the exact conversion between different freeform surface representations are presented.
It is the aim of this paper to introduce an integrated approach to spatiotemporal modeling of complex geographical structures and phenomena. This approach provides a model for capturing both static and dynamic aspects...
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ISBN:
(纸本)0444818383
It is the aim of this paper to introduce an integrated approach to spatiotemporal modeling of complex geographical structures and phenomena. This approach provides a model for capturing both static and dynamic aspects of the territory in order to realize a complete intensional representation of the application domain. The basic concepts are those of the object-oriented paradigm, but new primitives have been introduced to cope with the complexity and behavior of the real world. They are: complex objects, to represent structured entities and the relationships among entities;laws, to code the behavior of complex objects in the form of invariant relations;virtual objects, to express context-independent laws. The model is presented through examples of geographical entities and time-dependent properties.
All orientable metric surfaces are Riemann surfaces and admit global conformal parameterizations. Riemann surface structure is a fundamental structure and governs many natural physical phenomena, such as heat diffusio...
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ISBN:
(纸本)0780387880
All orientable metric surfaces are Riemann surfaces and admit global conformal parameterizations. Riemann surface structure is a fundamental structure and governs many natural physical phenomena, such as heat diffusion and electro-magnetic fields on the surface. A good parameterization is crucial for simulation and visualization. This paper provides an explicit method for finding optimal global conformal parameterizations of arbitrary surfaces. It relies on certain holomorphic differential forms and conformal mappings from differential geometry and Riemann surface theories. Algorithms are developed to modify topology, locate zero points, and determine cohomology type;of differential forms. The implementation is based on a finite dimensional optimization method. The optimal parameterization is intrinsic to the geometry, preserves angular structure, and can play an important role in various applications including texture mapping, remeshing, morphing and simulation. The method is demonstrated by visualizing the Riemann surface structure of real surfaces represented as triangle meshes.
This paper introduces a novel surface modeling method to stochastically distribute features on arbitrary topological surfaces. The generated distribution of features follows the Poisson-disk distribution, so we can ha...
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This paper introduces a novel surface modeling method to stochastically distribute features on arbitrary topological surfaces. The generated distribution of features follows the Poisson-disk distribution, so we can have a minimum separation guarantee between features and avoid feature overlap. With the proposed method, we not only can interactively adjust and edit features with the help of the proposed Poisson-disk map but can also efficiently redistribute features on object surfaces. The underlying mechanism is our dual tiling scheme, known as the Dual Poisson-Disk Tiling. First, we compute the dual of a given surface parameterization and tile the dual surface by our specially designed dual tiles;during the preprocessing, the Poisson-disk distribution has been pregenerated on these tiles. By dual tiling, we can nicely avoid the problem of corner heterogeneity when tiling arbitrary parameterized surfaces and can also reduce the tile set complexity. Furthermore, the dual tiling scheme is nonperiodic, and we can also maintain a manageable tile set. To demonstrate the applicability of this technique, we explore a number of surface modeling applications: pattern and shape distribution, bump mapping, illustrative rendering, mold simulation, the modeling of separable features in texture and BTF, and the distribution of geometric textures in shell space.
In this paper, we propose a generic framework for 3D surface remeshing. Based on a metric-driven Discrete Voronoi Diagram construction, our output is an optimized 3D triangular mesh with a user-defined vertex budget. ...
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In this paper, we propose a generic framework for 3D surface remeshing. Based on a metric-driven Discrete Voronoi Diagram construction, our output is an optimized 3D triangular mesh with a user-defined vertex budget. Our approach can deal with a wide range of applications, from high-quality mesh generation to shape approximation. By using appropriate metric constraints, the method generates isotropic or anisotropic elements. Based on point sampling, our algorithm combines the robustness and theoretical strength of Delaunay criteria with the efficiency of an entirely discrete geometry processing. Besides the general described framework, we show the experimental results using isotropic, quadric-enhanced isotropic, and anisotropic metrics, which prove the efficiency of our method on large meshes at a low computational cost.
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