In the generation of curved surfaces through a subdivision process, Sabin and Doo applied and extended Chaikin's algorithm to three dimensions by using linear combinations of the vertices of a polyhedron. A simila...
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In the generation of curved surfaces through a subdivision process, Sabin and Doo applied and extended Chaikin's algorithm to three dimensions by using linear combinations of the vertices of a polyhedron. A similar smoothing subdivision algorithm was brought out by Catmull and Clark. This paper describes an alternative algorithm which uses a similar approach but applies to sections of axisymmetric objects. It shows that axisymmetric free-formed surfaces can be generated easily and effeciently.
We present a novel algorithm for optimal control of nonlinear systems based on a subdivision algorithm. The algorithm presented in this paper is an alternative to a set-oriented approach for optimal feedback stabiliza...
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We present a novel algorithm for optimal control of nonlinear systems based on a subdivision algorithm. The algorithm presented in this paper is an alternative to a set-oriented approach for optimal feedback stabilization. We compare the proposed algorithm to the set-oriented approach, contrast these two approaches, and use examples to show that the new algorithm produces comparable results. Also, we demonstrate by example that we receive a precomputed optimal solution. The main contribution of the paper is understanding how cost function improves with further subdivision of state space and smaller memory footprint of the final solution in comparison with set-oriented approach. Copyright (c) 2012 John Wiley & Sons, Ltd.
With the aim to tackle the problems of the local shape adjustment and shape control of quartic Q-Ball curves, we propose two direct subdivision algorithms for quartic QBall curves, which include coefficient subdivisio...
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ISBN:
(纸本)9781538649916
With the aim to tackle the problems of the local shape adjustment and shape control of quartic Q-Ball curves, we propose two direct subdivision algorithms for quartic QBall curves, which include coefficient subdivision and tangent subdivision. According to the two subdivision algorithms, the corresponding modeling examples are respectively given. Studies show that the sub-curves are independent and have no influence on other sub-curves in shape adjustment, which realize the local shape adjustment of the quartic Q-Ball curves and maintain the geometric meaning of shape parameters. The modeling examples show that the proposed subdivision algorithms are effective and easy to implement, which greatly improve the abilities to express complex curves in shape design by adjusting the position and shape of quartic Q-Ball curves.
A novel real time Catmull-Clark subdivision algorithm on GPU is proposed. The algorithm divides a complicated 3D model into several kinds of simple fragments, and the subdivision masks of these simple fragments can be...
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ISBN:
(纸本)9781424441983
A novel real time Catmull-Clark subdivision algorithm on GPU is proposed. The algorithm divides a complicated 3D model into several kinds of simple fragments, and the subdivision masks of these simple fragments can be predefined. After the division of 3D models, these fragments are independent each other, thus can he subdivided in parallel in GPU. The proposed algorithm combines subdivision algorithm with programmable GPU and fully takes advantage of SPs' (stream processors) great ability of computation and parallel process. So the algorithm is more efficient.
Modern industrial manufacturing contains different kinds of surface modeling, which is processed by planar materials. For the principle of the most efficient materials using, how to optimize subdivision undevelopable ...
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ISBN:
(纸本)9783038352679
Modern industrial manufacturing contains different kinds of surface modeling, which is processed by planar materials. For the principle of the most efficient materials using, how to optimize subdivision undevelopable surface before development becomes an important topic in CAM design and manufacturing industries. The paper transforms the basic parameters of surface before subdivision, and gives the standards of subdivision surfaces. We proved the feasibility and the existence of triangle subdivision algorithm. By introducing double parameters MObius transformation, the subdivision surface is more uniform. At last, numerical examples prove that the algorithm about the approximate development of the undevelopable surfaces is effective and practical.
This paper proposes a subdivision algorithm for quartic λ-Bézier curves with shape parameter. Firstly, the quartic λ-Bézier curves are converted to quartic traditional Bezier curves, then we solve the cont...
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ISBN:
(纸本)9781728123264
This paper proposes a subdivision algorithm for quartic λ-Bézier curves with shape parameter. Firstly, the quartic λ-Bézier curves are converted to quartic traditional Bezier curves, then we solve the control points of the sub-curved curve after the subdivision by using the traditional Bezier curves so that it can remain shape unchanged before and after subdivision, that is, the expression of the curve is the same. Finally, it can be converted to the explicit combination expression of quartic λ-Bézier curves control points. The examples show that the proposed method is effective and easy to implement, which greatly enhances the ability to constructing complex surface by using quartic generalized λ-Bézier curves.
Phase equilibrium calculations at high pressures have been a continuous challenge for scientists and engineers. Traditionally, this task has been performed by solving a system of nonlinear algebraic equations originat...
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Phase equilibrium calculations at high pressures have been a continuous challenge for scientists and engineers. Traditionally, this task has been performed by solving a system of nonlinear algebraic equations originating from isofugacity equations. The reliability and accuracy of the Solutions are strongly dependent oil the initial guess, especially due to the fact that the phase equilibrium problems frequently have multiple roots. This work is focused on the application of a subdivision algorithm for thermodynamic calculations at high pressures. The subdivision algorithm consists in the application of successive subdivisions at a given initial interval (rectangle) of variables and a systematic test to verily the existence of roots in each subinterval. If the interval checked passes in the test, then it is retained;otherwise it is discharged. The algorithm was applied for vapor-liquid, solid-fluid and solid-vapor-liquid equilibrium as well as for phase stability calculations for binary and multicomponent systems. The results show that the proposed algorithm was capable of finding all roots of all high-pressure thermodynamic problems investigated. independent of the initial guess used.
A novel real time Catmull-Clark subdivision algorithm on GPU is proposed. The algorithm divides a complicated 3D model into several kinds of simple fragments, and the subdivision masks of these simple fragments can be...
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A novel real time Catmull-Clark subdivision algorithm on GPU is proposed. The algorithm divides a complicated 3D model into several kinds of simple fragments, and the subdivision masks of these simple fragments can be predefined. After the division of 3D models, these fragments are independent each other, thus can be subdivided in parallel in GPU. The proposed algorithm combines subdivision algorithm with programmable GPU and fully takes advantage of SPs' (stream processors) great ability of computation and parallel process. So the algorithm is more efficient.
Smooth interpolatory subdivision algorithms for the generation of curves are used to solve two point boundary value problems. A method of collocation is formulated for linear second order two point boundary value prob...
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Smooth interpolatory subdivision algorithms for the generation of curves are used to solve two point boundary value problems. A method of collocation is formulated for linear second order two point boundary value problems. It is proved that the algorithms produce smooth continuous solutions provided the algorithms are chosen appropriately. Error estimates for uniform partitions are also investigated. Finally, some numerical examples are given to show the convergence of the algorithms.
In this paper, a smooth interpolatory subdivision algorithm for the generation of interpolatory surfaces (GC(1)) over arbitrary triangulations is constructed and its convergence properties over nonuniform triangulatio...
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In this paper, a smooth interpolatory subdivision algorithm for the generation of interpolatory surfaces (GC(1)) over arbitrary triangulations is constructed and its convergence properties over nonuniform triangulations studied. An immediate application of this algorithm to surface interpolation to scattered data in R(n), n greater than or equal to 3 is also studied. For uniform data, this method is a generalization of the analyses for univariate subdivision algorithms, and for nonuniform data, an extraordinary point analysis is proposed and a local subdivision matrix analysis presented. (-)It is proved that the subdivision algorithm produces smooth surfaces over arbitrary networks provided the shape parameters of the algorithm are kept within an appropriate range. Some error estimates for both uniform and nonuniform triangulations are also investigated. Finally, three graphical examples of surface interpolations over nonuniform data are given to show the smoothing interpolating process of the algorithm.
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