Free- form surface的用法和样例：
例句
- Then the equation sets were solved by difference method to get the surface data of the free reflector.
采用差分法求解微分方程组得到自由曲面反光器的面形数据。 - When a freeform surface is being milled, the interference may exist anywhere around the cutter circumference, in addition to the tool-driving plane.
加工自由曲面时，刀具干涉可能出现在包括刀具驱动面在内的刀具周围任何区域。
