基于 NURBS 的多面体圆角过渡算法  

NURBS based skinning rounding method

作　　者：吴怀军[1] 孙家广[1] 杨长贵[1] 

机构地区：[1]清华大学计算机科学与技术系

出　　处：《清华大学学报（自然科学版）》1997年第9期118-122,共5页Journal of Tsinghua University(Science and Technology)

基　　金：国家"八五"科技攻关项目

摘　　要：多面体的圆角过渡是ＣＡＤ／ＣＡＭ中的一种重要操作。该文研究了多面体的边端点附近的情形，给出了直接计算边过渡曲面ＮＵＲＢＳ控制点的算法，避免了复杂的求交、分类和裁剪；分析了任意三边构成的角点的过渡曲面形状，给出了各种情形下角点过渡曲面的非均匀有理Ｂ样条（ＮＵＲＢＳ）表示的生成算法；针对产品造型中常见的情形给出了快速算法。文中算法生成的过渡曲面都是ＮＵＲＢＳ曲面，它们与其基曲面间以及沿边过渡曲面与角过渡曲面的公共边界均满足Ｇ１连续。Rounding of polyhedra is an important operation in CAD/CAM. This paper studies the situation around the vertex of an edge and presents the algorithm to calculate the NURBS control net of the edge rounding and avoid the complicated intersection, clarification and trimming. It also analyses the different shapes of the rounding at the corner formed by arbitary three edges. It gives the generating algorithm of the nonuniform rational B spline (NURBS) rounding at the corner under each situation and presents fast algorithm for the most commonly used condition in product modeling. Every surface generated is a NURBS surface and G 1 continuity is satisfied between roundings and their base planes and along common edges between edge roundings and corner rounding.

关 键 词：圆角过渡 CAD CAM 多面体 NURBS曲面 

分 类 号：TP391.7[自动化与计算机技术—计算机应用技术]