分布于空间曲面上的三维等值线的生成

本文提出了一种分布在空间曲面上的三维等值线的生成算法。该法首先用双参数曲面插值法来拟合所需曲面，曲面以双参数网格线表示，网格线的交点形成网格点阵；其次，按某个视线方向从该点阵中删除被背景曲面自身遮挡了的点；然后，从背景曲面的边界到内部逐个地搜索定义于背景曲面上某物理量的等值点，并按一定的规则将其连成等值线；最后，再按前述视线方向将等值线连同曲面网格一起投影到显示平面上。

The Generation of Three-Dimensional Contour Line on the Surface of a Body

A kind of algorithm is presented for the generation of three-dimensional contours that represent the variation of a physical quantity distributed on the surface of a body. For this study, the physical quantity was approximated by a discrete, three-dimensional grid on the surface of the body created by spline function. We searched each grid for picking up the 3D point position on which the quantity was equal to the designated contour level. Then these special points were connected in some contours according to a certain rule. These contours and the projection of the physical quantity grid on the surface of the body were projected to a display plan after deleting the hide lines.