flatten_unflatten.py

import numpy as np

# Single point cloud case

point_cloud = np.random.rand(6,3) # 6 3D points
flattened = point_cloud.reshape(point_cloud.shape[0],-1) # One point in R^18
unflattened = flattened.reshape(-1,3) # 6 3D points

# Check that they're identical
print point_cloud
print unflattened

# Multiple point clouds case

point_clouds = np.random.rand(12,6,3) # 12 3D point clouds, each with 6 points
flattened = point_clouds.reshape(point_clouds.shape[0],-1) # 12 points in R^18
unflattened = flattened.reshape(flattened.shape[0],-1,3) # 12 3D point clouds, each with 6 points

# Check that they're identical
print point_clouds
print unflattened