• 中国计算机学会会刊
  • 中国科技核心期刊
  • 中文核心期刊

J4 ›› 2011, Vol. 33 ›› Issue (6): 57-62.doi: 10.3969/j.issn.1007130X.2011.

• 论文 • 上一篇    下一篇

两种带形状参数的曲线

严兰兰1,2,梁炯丰3   

  1. (1.东华理工大学数学与信息科学学院,江西 抚州 344000;
    2.东华理工大学放射性地质与勘探技术国防重点学科实验室,江西 抚州 344000;
    3.东华理工大学土木与环境工程学院,江西 抚州 344000)
  • 收稿日期:2009-05-13 修回日期:2009-08-26 出版日期:2011-06-25 发布日期:2011-06-25
  • 作者简介:严兰兰(1982),女,湖北浠水人,硕士,讲师,研究方向为计算机辅助几何设计。梁炯丰(1980),男,广西藤县人,博士生,讲师,研究方向为结构工程。
  • 基金资助:

    东华理工大学校长基金资助项目(DHXK0808)

Two Kinds of Curves with Shape Parameters

YAN Lanlan1,2,LIANG Jiongfeng3   

  1. (1.School of Mathematics and Information Science,East China Institute of Technology,Fuzhou 344000;
    2.Key Laboratory of Radioaction Geology and Exploration Technology Fundamental Science for National Defense,
    East China Institute of Technology,Fuzhou 344000;
    3.School of Civil and Environmental Engineering,East China Institute of Technology,Fuzhou 344000,China)
  • Received:2009-05-13 Revised:2009-08-26 Online:2011-06-25 Published:2011-06-25

摘要:

本文构造了两种带参数的三角样条基,基于这两组基定义了两种三角样条曲线。与二次B样条曲线类似,这两种曲线的每一段都由相继的三个控制顶点生成。这两种曲线具有许多与二次B样条曲线类似的性质,但它们的连续性都比二次B样条曲线更好。对于等距节点,在一般情况下,这两种曲线都整体C3连续,在特殊条件下,它们都可达C5连续。两种曲线中的形状参数均有明确的几何意义,参数越大,曲线越靠近控制多边形。另外,当形状参数满足一定条件时,这两种曲线都具有比二次B样条曲线更好的对控制多边形的逼近性。运用张量积方法,将这两种曲线推广后所得到的曲面也具有较好的连续性。

关键词: 计算机应用, 三角基, 样条曲线, 形状参数

Abstract:

Two kinds of trigonometric spline bases are constructed in this paper. Based on these bases, two kinds of trigonometric spline curves are defined. As each piece of these trigonometric spline curves are generated by three consecutive control points, these curves retain many properties of the quadratic Bspline curve, but they have a higher order of continuity than the quadratic Bspline curve. For equidistant knots, these curves are C3continuous, and they are C5 continuous under special conditions. The shape parameters of the curves have an explicit geometric meaning. The curves approach the control polygon as the parameter increases. Besides, these curves are closer to the control polygon than the quadratic Bspline curve when the shape parameters are under special conditions. By using the tensor product method, the two kinds of curves can be extended to surfaces. The surfaces have a higher order of continuity than the biquadratic Bspline surfaces.

Key words: computer application;trigonometric basis;spline curve;shape parameter