基于拓扑相似性的等距参数曲面求交算法

等距曲面求交算法通常采用曲面求交算法反复迭代计算交线,没有考虑不同Offset距离等距曲面交线的相似性进行求交简化.提出了一种基于拓扑相似性的等距曲面求交优化算法.算法首先求取曲面的拓扑特征点,根据拓扑特征点分布图,确定交线环拓扑结构,在交线拓扑结构信息的指导下,确定初始点的搜索策略.采用提出的方法可以有效解决等距曲面的子环、奇点遗漏、分支跳跃、乱序跟踪和初始点求取问题,精确、鲁棒地计算出交线.

An Intersection Algorithm for Parametric Offsets Surfaces Based on Topology Similarity

Commonly, surface/surface intersect algorithm is repeatedly used to solve the offset surface/surface intersections. It doesn't make full use of similarity of intersect curve topology to simple offset surface/surface intersection problem. The algorithm presented in this paper pre-processes two parametric surfaces to achieve points, called topology transition points, which produce an effect on intersect curve structure, number and location. According to topology transition points distribution graph, initial point search strategy and intersect curve topology can be fixed. The algorithm is tested, and can be proved to overcome the degenerate conditions such as loop leaking, singularity leaking and can calculate the initial point effectively.