Catmull-Clark细分曲面的变距离偏置  

Variable offset of Catmull-Clark subdivision surface

作　　者：何钢[1] 廖文和[1] 刘浩[1] 李秀娟[1] 

机构地区：[1]南京航空航天大学机电学院,南京210016

出　　处：《东南大学学报（自然科学版）》2008年第3期424-428,共5页Journal of Southeast University：Natural Science Edition

基　　金：国防基础科研资助项目

摘　　要：给出了一种Catmull-Clark细分曲面的变距离偏置实现算法.在指定初始控制顶点对应极限点的偏置距离和偏置权值后,对基网格进行适当加密,新顶点的偏置距离采用带偏置权值的插值细分方法计算;然后在基网格控制顶点对应极限点的法向偏移指定距离,采用反复迭代的方法求解变距离偏置曲面的控制网格,保证了控制顶点对应极限点的精确偏置.变距离偏置不仅将偏置距离为常值的等距作为特例,而且作为一种曲面造型手段,可以实现细分曲面的局部成型特征和不均匀厚度薄壳体的构造,增强了细分曲面的造型功能.An algorithm is presented to implement variable offset of Catmull-Clark subdivision surfaces. After assigning offset distances and offset weights to control vertices, offset distances of new vertices generated during subdivision are determined by the weighted interpolatory subdivision meth- od. Then offsetting corresponding distances at the normal of control vertex＇s limit points, control meshes of offset surfaces are generated using iterative method, which assures exact offsetting at control vertex＇s limit points. Variable offset takes constant offset as a special case and becomes an important modeling method that can implement local features on subdivision surfaces and construct shells with non-uniform thickness. This method improves the modeling ability of subdivision surfaces.

关 键 词：变距离偏置 CATMULL-CLARK细分 局部偏置 偏置权值 

分 类 号：TP391.7[自动化与计算机技术—计算机应用技术]