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Your search keyword '"Yong, Jun-Hai"' showing total 9 results
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9 results on '"Yong, Jun-Hai"'

1. Projecting points onto planar parametric curves by local biarc approximation

Author

Song, Hai-Chuan, Xu, Xin, Shi, Kan-Le, Yong, Jun-Hai, cgcad, Thss, Tsinghua University [Beijing] (THU), School of Software (THSS), and Tsinghua, Thss

Subjects
[INFO.INFO-GR] Computer Science [cs]/Graphics [cs.GR], [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract

International audience; This paper proposes a geometric iteration algorithm for computing point projection and inversion on planar parametriccurves based on local biarc approximation. The iteration begins with initial estimation of the projection of theprescribed test point. For each iteration, we construct a biarc that locally approximates a segment on the originalcurve starting from the current projective point. Then we compute the projective point for the next iteration, as well asthe parameter corresponding to it, by projecting the test point onto this biarc. The iterative process terminates whenthe projective point satisfies the required precision. Examples demonstrate that our algorithm converges faster and isless dependent on the choice of the initial value compared to the traditional geometric iteration algorithms based onsingle-point approximation.

Published
2014

2. Constructing G1 quadratic Bezier curves with arbitrary endpoint tangent vectors

Author

Gu, He-Jin, Yong, Jun-Hai, Paul, Jean-Claude, (frank) Cheng, Fuhua, Jiangxi Academy of Sciences, Nanchang, School of Software (THSS), Tsinghua University [Beijing] (THU), Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria), University of Kentucky (UK), Tsinghua University [Beijing], and University of Kentucky

Subjects
[INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract

International audience; Quadratic Bézier curves are important geometric entities in many applications. However, it was often ignored by the literature the fact that a single segment of a quadratic Bézier curve may fail to fit arbitrary endpoint unit tangent vectors. The purpose of this paper is to provide a solution to this problem, i.e., constructing G1 quadratic Bézier curves satisfying given endpoint (positions and arbitrary unit tangent vectors) conditions. Examples are given to illustrate the new solution and to perform comparison between the G1 quadratic Bézier cures and other curve schemes such as the composite geometric Hermite curves and the biarcs.

Published
2009

3. Computing the minimum distance between two planar algebraic curves

Author

Chen, Xiao-Diao, Yong, Jun-Hai, Wang, Guozhao, Hangzhou Dianzi University (HDU), School of Software (THSS), Tsinghua University [Beijing] (THU), Department of Mathematics [Hangzhou], Zhejiang University, and Tsinghua, Thss

Subjects
[INFO.INFO-GR] Computer Science [cs]/Graphics [cs.GR], [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract

National audience; Through geomet ric observation , it is found that the nearest point on a curve is a tangent point between the curve and an off set curve of the other curve. Based on this observation , an off set method is presented for computing the minimum distance between two planar algebraic curves. The new method is geomet rically inst ructive , and can be used for computing the minimum distance between an algebraic curve and a parametric one on the same plane. For planar quadratic curves , the degree of the resulting univariate polynomial equation by our method is much lower than that of the equations in previous comparable methods , which may lead to lower computation complexity or higher robustness of the solutions.

Published
2008

4. Adaptive geometry compression based on 4-point interpolatory subdivision schemes with labels

Author

Zhang, Hui, Yong, Jun-Hai, Paul, Jean-Claude, School of Software (THSS), Tsinghua University [Beijing], Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria), and Tsinghua University [Beijing] (THU)

Subjects
[INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract

International audience; We propose an adaptive geometry compression method with labels based on 4-point interpolatory subdivision schemes. It can work on digital curves of arbitrary dimensions. With the geometry compression method, a digital curve is adaptively compressed into several segments with di®erent compression levels. Each segment is a 4-point subdivision curve with a subdivision step. Labels are recorded in data compression to facilitate merging those segments in data decompression. In the meantime, we provide high-speed 4-point interpolatory subdivision curve generation methods for e±ciently decompressing the compressed data. For an arbitrary positive integer k, formulae of the number of the resultant control points of a 4-point subdivision curve after k subdivision steps are provided. Some formulae for calculating points at the kth ubdivision step are presented as well. The time complexity of the new approaches is O(n), where n is the number of the points in the given digital curve. Examples are provided as well to illustrate the efficiency of the proposed approaches.

Published
2007

5. Standardization of Rational Bézier Surfaces

Author

Yang, Yi-Jun, Yong, Jun-Hai, Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria), School of Software (THSS), Tsinghua University [Beijing] (THU), and Tsinghua University [Beijing]

Subjects
Computer Science::Graphics, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR]
Abstract

National audience; The sufficient and necessary condition for the existence of linear Möbius transformations that can standardize the rational Bézier surfaces is given based on Möbius reparameterization theorem. To obtain the standard form of an arbitrary cubic rational Bézier surface, we then present a quadratic reparameterization algorithm to reparameterize the surface so that all the corner weights of the surface are equal to one. Examples are included to show the performance of the new method.

Published
2007

6. Point projection for B-Spline surfaces

Author

Chen, Xiao-Diao, Paul, Jean-Claude, Sun, Jia-Guang, Yong, Jun-Hai, Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria), Purdue Research and Education Center for Information Systems in Engineering (PRECISE), and Purdue University [West Lafayette]

Subjects
[INFO.INFO-IA]Computer Science [cs]/Computer Aided Engineering
Abstract

Submission Mar 31, 2007, revised.; International audience

Published
2007

7. INTERSECTION ALGORITHM BETWEEN A CYLINDER AND A GENERAL QUADRIC SURFACE

Author

Li, Xiao-Wu, Yong, Jun-Hai, Chen, Xiao-Diao, Fu, Li, Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria), School of Software (THSS), Tsinghua University [Beijing] (THU), Delft University of Technology, and Tsinghua University [Beijing]

Subjects
geo- metric modeling, cylinder, quadric surface, [INFO.INFO-IA]Computer Science [cs]/Computer Aided Engineering, computer-aided design, inter- section
Abstract

Site de la conférence : http://www.io.tudelft.nl/caidcd2005/; In BRep geometric modeling system, the positions of end-points of the resultant intersection curves (called key points as well) are very important for many other operations, such as boolean operations. This paper provides a method to determine the positions of the end-points of the intersection curves between a cylinder and a quadric surface. Our algorithm ¯rst turns the original intersection problem into another intersec- tion problem between a set of line segments and a quadric surface, and obtains the parametric form of the intersection curves. Then, it computes all the key positions. Finally, it calculates the intersec- tion intervals and their corresponding intersection curves by mid-point judging method. The algo- rithm has been applied in the commercial software Gems6.0, and practical experiences show both ro- bustness and e±ciency of the new algorithm.

Published
2005

8. An algorithmnext term for previous termtetrahedral mesh generation based on conforming constrained Delaunay tetrahedralizationnext term

Author

Sun, Jia-Guang, Yang, Yi-Jun, Yong, Jun-Hai, Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, and Institut National de Recherche en Informatique et en Automatique (Inria)

Subjects
Finite element methods, Octree, CCDT, [INFO.INFO-IA]Computer Science [cs]/Computer Aided Engineering
Abstract

An unstructured previous termtetrahedral mesh generation algorithmnext term for 3D model with constraints is presented. To automatically generate a previous termtetrahedral meshnext term for model with constraints, an advancing front previous termalgorithmnext term is presented previous termbased on conforming constrained Delaunay tetrahedralizationnext term (CCDT). To reduce the number of visibility tests between vertices with respect to model faces as well as the computation of previous termconstrained Delaunaynext term tetrahedra, a sufficient condition for DT (previous termconstrained Delaunay tetrahedralizationnext term whose simplexes are all previous termDelaunay)next term existence is presented and utilized coupled to uniform grid and advancing front techniques in our previous termalgorithm. The meshnext term generator is robust and exhibits a linear time complexity for mechanical models with uniform density distribution.

Published
2005

9. Automatic G1 arc spline interpolation for closed point set

Author

Chen, Xiao-Diao, Paul, Jean-Claude, Sun, Jia-Guang, Yong, Jun-Hai, Zheng, Guo-Qin, Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, and Institut National de Recherche en Informatique et en Automatique (Inria)

Subjects
Hermite spline, 010103 numerical & computational mathematics, 02 engineering and technology, 01 natural sciences, Industrial and Manufacturing Engineering, Multivariate interpolation, Combinatorics, Polyharmonic spline, Smoothing spline, 0202 electrical engineering, electronic engineering, information engineering, Arc spline, G1 continuity, Closed point set, 0101 mathematics, Thin plate spline, Circular arc interpolation, Mathematics, Mathematical analysis, 020207 software engineering, [INFO.INFO-IA]Computer Science [cs]/Computer Aided Engineering, Computer Graphics and Computer-Aided Design, Computer Science Applications, Spline (mathematics), Computer Science::Graphics, Spline interpolation, Interpolation
Abstract

A method for generating an interpolation closed G1 arc spline on a given closed point set is presented. For the odd case, i.e. when the number of the given points is odd, this paper disproves the traditional opinion that there is only one closed G1 arc spline interpolating the given points. In fact, the number of the resultant closed G1 arc splines fulfilling the interpolation condition for the odd case is exactly two. We provide an evaluation method based on the arc length as well such that the choice between those two arc splines is made automatically. For the even case, i.e. when the number of the given points is even, the points are automatically moved based on weight functions such that the interpolation condition for generating closed G1 arc splines is satisfied, and that the adjustment is small. And then, the G1 arc spline is constructed such that the radii of the arcs in the spline are close to each other. Examples are given to illustrate the method.

Published
2004

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