词:二次均匀B样条;BB基函数;曲线曲面;插值;保形
中图分类号:TP391文献标识码:ADoI: 10.3969/j.issn.1003-6970.201
2.03.012
C1 Interpolating Quadratic Uniform B-Spline Curves and SurfacesJIN Xi-juan1, Yao Jie2, faNG Kui2
(1.Department of Electronic and Communication, Changsha University, Changsha, 410003, China;
2.College of Information Science & Technology, Hunan Agricultural University, Changsha, 410128, China)
【Abstract】according to the endpoint properties of quadratic uniform B-spline curve, a new basic function-BB basis function is de
rived . C1preserving shape interpolating quadratic uniform B-splinecurves are obtained by BB basis functions, and C1 interpolating biquadratic uniform B-spline surfaces are constructed.
【Key Words】quadratic uniform B-spline; BB basic functions; Curve surfaces; Interpolation; Preserving shape
0 引 言
参数曲线曲面是CAGD探讨的内容[1-3],的Bézier策略、B样论文格式范文条策略,NURBS策略因其良好的光顺性、凸包性、形状可调性等,而受到的,并广泛运用于机械、汽车、航天等领域。
这几种策略在插值却有之处, Bézier策略的光滑拼接条件苛刻,B样条策略和NURBS策略不具有插值功能。传统的策略是反算制约顶点[3-5],策略需解大型线性方程,计算费用,且曲线的形状局部修改,不利于实际曲线曲面造型,并且修改数据点将影响整个曲线或曲面;是构造辅助点分段拼接[6-7];是用迭代法近似计算B样条的制约政治论文顶点[8-9]。
具有保凸的均匀二次B样条和均匀三次B样条插值曲线。在给定的制约多边形的每2个顶点之间插人2个deBoor点,由这些deBoor点形成新的制约多边形,所产生的均匀B样条曲线插值于给定的制约多边形的顶点。建立相邻四个插值点与新的制约顶点的联系,以而构造一组插值基函数,插值曲线由所构造的基函数和型值点表示,插值曲线具有保凸性和C1连续性。
文献
Bohemtal W,A survey of curve and surface methods in CAGD[J].CAGD,1984,(1):1-60
Tgoodman T N,Ong B H. Shape preserving interpolation by space curve[J].CAGD,1997,15:1-17
[3]施法中.计算机辅助几何设计与非均匀有理B样条[M].北京:高等教育出版社,2001
[4]王天军.反求Bézier曲线制约点的算法[J].计算机辅助设计与图形学学报,1992,4(3):36-40
[5]方逵.曲线曲面的设计技术与原理[M]. 长沙:国防科技出版社,1997
[6]邓四清.C1插值三次样条曲线曲面[J].计算机工程与运用,2010,Vol.46, No.34:158-160
[7]方逵,赵军,谭建荣.带有给定切线多边形的保形有理三次B样条曲线[J].工程图学学报,1996,No.2:99-105
[8]Yamagushi,F.A new curve fitting method using a CRT computer display[J]. Graphics and Processing,1978,7:425-437
[9]阑宏伟,王国瑾,董辰世.用迭代非均匀B-Spline曲线(曲面)拟合给定点集[J].科学,2003,
Vol.33 No.10
[10]方逵,欧新良.计算机辅助几何设计凸性浅析论述及算法[M]. 长沙:湖南科技出版社,2011
[11]方逵等.插值平面曲线的可展B样条曲面及凸性浅析.计算机工程与运用,2008,44(3):45-46