文件名称:sectorbuffer
介绍说明－－下载内容均来自于网络，请自行研究使用
先对点做指定半径的圆形缓冲区，然后根据某个方向做一扇形的缓冲区
-First generate loop buffer according to appointed point, then generate sector butter according to direction
-First generate loop buffer according to appointed point, then generate sector butter according to direction
(系统自动生成,下载前可以参看下载内容)
下载文件列表
sectorbuffer.txt