基于反射线模型修改NURBS曲面不光顺性

作者：高 斌1，朱景华1，徐振宇1，宋小文2 日期：2007-08-31/span> 浏览：3904 查看PDF文档

                                   基于反射线模型修改NURBS曲面不光顺性*
                                    高 斌1，朱景华1，徐振宇1，宋小文2
                            （1.温州职业技术学院 机械工程系，浙江 温州 325035；
                                2.浙江大学 机械与能源工程学院，浙江 杭州 310027）

摘 要：反射线模型是一种评估曲面光顺性的强有力工具。提出了一种基于反射线模型修改NURBS曲面局部不光顺性的新方法，将反射线不规则部分用期望形状的5次B样条曲线替换，通过指定新反射线部分点的入射线方向，将所得反射线修改模型对应的非线性方程组转化成线性方程组，大大简化了问题的复杂性。新NURBS曲面具有指定的反射线形状，某些点具有间接确定的法线方向。该方法直观、适用于实时交互设计。最后以实例验证了算法的有效性。
关键词：反射线；NURBS曲面；光顺性；形状修改

                        Removing local unfairness of NURBS surfaces based on reflection line model
                     GAO Bin1, ZHU Jinghua1, XV Zhenyu1, SONG Xiaowen2
  （1.Department of Mechanical Engineering, Wenzhou Vocational & Technical College, Wenzhou 325035, China;
2.College of Mechanical and Energy Engineering, Zhejiang University, Hangzhou 310027, China）

Abstract: The reflection line model is a powerful tool in assessing the fairness of a surface. A new method was presented to remove the local unfairness of NURBS surface by adjusting reflection lines and specifying theirs incident ray vectors. The nonlinear equations of reflectionline modification model was transformed into linear equations, and hence greatly reduced the complexity of computation. The new NURBS surface has the certain reflection lines that designer specifies, and some point on the new surface has the certain normal that designer specifies indirectly. The method is intuitive and suitable for realtime interactive design. The effectiveness of the new method is proved by example．
Key words: reflection lines; NURBS surface; fairness; shape modification

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