However, such basic shapes fall short of expectations when it comes to some heavy duty vector drawing.
然而，当需要画一些复杂的矢量图时，这些基础图形就不够用了。
2
This vector is called a normal vector or normal for short.
这一向量就称为法线向量或简称为法线。
3
In short, vector data take the simplest topological entities — points, lines, and polygons — and anchor them within a 2-d Cartesian coordinate system to describe geographical features.