Abstract: This paper researches into an current aigorthm of drawing section plane lines of plane graphics with arbitray circlearc. A method of expanding vector product in 2D plane to 3D space is presented. The problem deciding effective intersec-tion of straight line intersecting circle are is solved by using vector method.

Key words: circle arc, section plane line, vector, 2D plane, 3D space, computer drawing

摘要： 本文研究了画带任意圆弧平面图形剖面线的通用方法，提出了将二维(2D)平面上两矢量的交积扩展到三维(3D)空间内进行交积，从而用矢量法解决了剖面线与圆弧相交时有效交点的确定问题。

关键词: 圆弧, 剖面线, 矢量, 2D平面, 3D空间, 计算机绘图