基于广义离散分解trimmed曲面  

DECOMPOSITION OF TRIMMED SURFACES VIA GENERALIZED SUBDIVISION

作　　者：胡事民[1] 孙家广[1] 汪国昭[2] 

机构地区：[1]清华大学计算机科学与技术系 [2]浙江大学应用数学系

出　　处：《计算机学报》1999年第3期296-301,共6页Chinese Journal of Computers

基　　金：国家自然科学基金

摘　　要：在几何造型系统中，复杂形体往往由Ｔｒｉｍｍｅｄ曲面拼合而成，因此Ｔｒｉｍｍｅｄ曲面的表示与处理在计算机辅助设计中非常重要．本文应用Ｂéｚｉｅｒ曲面的广义离散算法，研究了ｔｒｉｍｍｅｄＢéｚｉｅｒ曲面的表示问题．分别利用约束优化方法和图形学中的扫描线思想，给出了ｔｒｉｍｍｉｎｇ线的Ｂéｚｉｅｒ函数逼近和ｔｒｉｍｍｅｄ曲面参数域的分解算法．通过分解参数域，将ｔｒｉｍｍｅｄ曲面表示为多张完整的Ｂéｚｉｅｒ矩形片．Since most complex objects are generated by some sort of trimming process in geometric modeling system, the representation and processing of trimmed surfaces are very important in CAD.This paper investigates representations of trimmed Bézier surfaces by using generalized subdivision of rectangular Bézier surfaces. Applying constrained optimization methods and idea of scan line of computer graphics respectively,methods for approximating trimming curves by Bézier functions and algorithms for decomposing parameter domain of trimmed surfaces are developed. A trimmed Bézier is represented as a union of some integral Bézier surfaces by decomposing its domain.

关 键 词：TRIMMED曲面 广义离散 TN法 几何造型 CAD 

分 类 号：TP391.72[自动化与计算机技术—计算机应用技术]