Conversion between pointcloud and numpy arrays in open3d

open3d In the use of open3d.io.read_point_cloud() After reading point cloud data , The return is pointcloud Data of type , Sometimes I wish I could use numpy Handle point clouds , At this time, the conversion between the two is required ( Strictly speaking, the data is just copied and then transmitted ).
1.pointcloud convert to numpy

import numpy as np
import open3d as o3d
A=[]
pcd=o3d.io.read_point_cloud("/bunny.ply")# The path should be set according to the actual situation 
A=np.asarray(pcd.points)#A Has become a n*3 Matrix 
print(A)

2.numpy The data in the array is converted into pointcloud

# here B Is already a n*3 Of numpy.ndarray( That is, common array types )
pcd=o3d.geometry.PointCloud()# Instantiate a pointcloud class 
pcd.points=o3d.utility.Vector3dVector(B)# Pass in coordinate data to this class , here pcd.points It is already a point cloud 
o3d.visualization.draw_geometries([pcd.points])# Show me