以多种方式绘图（透明，灰度，缩放）,这个文件显示的是个3D模型,适用于初学者研究-drawings in a variety of ways (transparent, gray, zoom), the documents show is the 3D model, Study applies to beginners

读取off文件数据，渲染显示3D模型，可以选择渲染的东西，自带off文件。-Read off the file data, rendering to display 3D model, you can the rendering of things, comes off the file.