中文摘要：

本文阐述了基于等值线法的非均匀有理B样条（Non-Uniform Rational B-Splines，NURBS）曲面与隐式曲面求交算法的原理，并提出了一种改进算法。通过缩小等值线的搜寻区间，采用拟牛顿迭代法求交点，使用B样条曲线拟合参数域上的交线等改进算法，提高了NURBS曲面与隐式曲面求交算法的效率和精度。论文通过Matlab编制程序实现了该算法，并讨论了该算法在船体曲面求交过程中的应用。

英文摘要：

An improved algorithm for the intersection of NURBS surface and implicit surface is introduced in this research. By narrowing intersection search region in the parameter domain and by using quasi-Newton iteration method for intersection point and using B spline to fit the intersection line in parameter domain, the efficiency and accuracy of the algorithm has greatly improved especially with dense regular meshes, compared with the algorithm based on isolines. Some applications to hull surface intersections are also discussed in this research.