RCS计算中NURBS曲面和射线求交的快速计算

A Fast Algorithm for Intersection Calculation of Ray and NURBS Surface in Predicting Radar Cross Section Calculation

提出了一种基于牛顿迭代法解方程组的射线和NURBS曲面求交算法。利用预先计算射线和曲面交点个数最大值,通过折中适应性分割曲面得到迭代初始值,达到了快速计算的效果。同时,解决了射线与NURBS曲面多交点判断、自交点筛选等问题,保证了交点精度,且不会遗漏交点。

A fast intersection algorithm for ray and NURBS surface is presented. The algorithm bases on the Newton iteration solution for equation set. By predicting the maximum of intersection points of ray and NURBS surface and dividing surface in half-adapting fashion, the proper preliminary value for iteration can be obtained, so that the fast calculation can be reached. Meanwhile, this algorithm solves some problems, such as judgment of multi intersection points and filter of self-intersection points, to grantee the precision of intersection points.