直线与高精度细分曲面交点快速计算方法

为解决直线与高精度细分曲面求交效率低和稳定性差的问题,利用细分曲面网格拓扑结构特性,研究直线与Catmull-Clark细分曲面求交的高效方法.首先,构造一个新的数据结构,实现Catmull-Clark细分曲面的分片表示.然后,对每个细分曲面面片创建轴对称包围盒,结合包围盒干涉检测技术,快速排除不与直线相交的细分曲面面片,根据细分曲面面片网格拓扑结构特性,提出细分曲面面片多级分割技术.最后,通过一定级别的分割并结合轴对称包围盒干涉检测技术,快速锁定与直线相交的四边形面片并获得交点.

An efficient algorithm for computing intersection between line and high precision subdivision surface

To accurately measure the liquid-solid fraction of casting slab in the secondary cooling zone and precisely predict the final solidifying end of casting slab, a novel method, which is called vibration method, is presented to detect the liquid-solid fraction and locate the liquid core end of continuous casting slab, based on theoretical analyses, physical simulation and experimental validation. The feedback patterns of exciting force signal and forced vibration displacement signal are concluded, the effects that vibration frequency and exciting force impact on the phase difference are compared. And the feasibility of detection scheme is proved. The research results provide guidance and reference for the on-line detection of liquid-solid fraction and final solidifying end of the slab.