CAD三维制图 三维绘图术语和坐标系 ◆视图观测点的设立方法 ◆绘制三维点和曲线 ◆绘制三维网格 ◆绘制三维实体 ◆通过二维对象创建三维对象 -◆ view observation points set up method of CAD 3D drawing 3D graphics terminology and coordinate system ◆ draw the 3D points and curves In ◆ draw three-dimensional