Python将numpy（.npy文件）存储为.ply文件
安装Open3D
pip install open3d
From NumPy to Ply
# Pass xyz to Open3D.o3d.geometry.PointCloud and visualize
pcd = o3d.geometry.PointCloud()
pcd.points = o3d.utility.Vector3dVector(xyz)
o3d.io.write_point_cloud("../../TestData/sync.ply", pcd)
其中xyz即为存储点云xyz坐标的numpy，
维度为(N,3)
，N为点云的点数，3为xyz坐标。
Open3D文档
http://www.open3d.org/docs/0.9.0/tutorial/Basic/working_with_numpy.html