在逆向工程中通过测量仪器得到的产品外观表面的点数据集合也称之为点云，通常使用三维坐标测量机所得到的点数量比较少点与点的间距也比较大，叫稀疏点云；而使用三维激光扫描仪或照相式扫描仪得到的点云点数量比较大并且比较密集，叫密集点云。-Data collection point in the surface appearance of the product obtained by reverse engineering measurement instruments, also known as point clouds, usually spaced three-dimensional coordinate measuring machine number of points obtained in relatively small dots are relatively large, called sparse point cloud　while the number of point cloud using the three-dimensional laser scanner or camera scanner get bigger and more intensive, called dense point clouds.