实体造型中点面分类算法研究

Research on Algorithms of Point-Face Classification in Solid Modeling

在曲面的几何法表示基础上，利用“射线法”实现了曲面的点面分类．以圆和椭圆为例给出了和分类算法相关的空间直线和空间二次曲线交点的求法，并且利用裁剪曲面的思想表示曲面的交线，解决了曲面实体造型中曲面上的点和曲面及其轮廓边的位置关系的判断．

For solid modeling, there is an important algorithm of determing the positional relationship between apoint and a face, i. e. point-face classification. A point-face classification of curved-surface is implemented by using ray-firing on the basis of geometric representations. Algorithms of finding intersection points between spece linesand space conics relating to point-face classification are presented with circle and ellipse as examples. Also, principles of trimmed-suffaces are used to represent intersection curves between curved-surfaces in order to determiningpositional relationships between points on surfaces and boundary edges of surfaces in solid modeling based oncurved-surfaces.