基于网格的球面上等距线的构造方法  

Mesh Based Offset Algorithm for Curves on Spherical Surfaces

作　　者：舒莲卿[1,2] 余正生[1] 杜辉[2] 

机构地区：[1]杭州电子科技大学图形图像研究所,浙江杭州310018 [2]浙江传媒学院,浙江杭州310018

出　　处：《计算机仿真》2010年第7期321-325,共5页Computer Simulation

摘　　要：构造曲面上曲线的等距线是计算机辅助几何设计中一个重要的工具,鉴于已有的等距线构造方法会产生局部无效环,为优化上述问题,提出了一种新的球面上曲线的等距线构造方法。利用球面三角化技术将球面分割成多个三角片;并将球面与某一空间隐式曲面求交,求得的交线作为球面上的基曲线,用逐步递增求等距的方法,求出球面基曲线的等距线。在逐步递增求等距的过程中能消除局部无效环。仿真结果表明,方法能快速有效地构造球面上曲线的等距线,达到理想的效果。Offset of curves on surfaces is an important tool in computer aided design.Because the existed algorithms always generate local invalid loop,a new offset algorithm for curves on spherical surfaces is proposed.Firstly, the spherical surface is divided into many triangles by taking the technology of conversion from spherical surface to triangle mesh.The initial curve on spherical surface is generated by calculating the cross line segments between triangle mesh and a plane.Secondly,by using the incremental approach of the algorithm to compute offset points for all the points of initial curve on the triangle mesh,the final offset curve position is obtained after connecting the offset points.Experiments show that the proposed approach completely eliminates the formation of local self - intersections and can compute the offset curves for curve on spherical surfaces quickly and effectively.

关 键 词：等距线 三角网格 局部无效环 球面上的曲线 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]