If you want to create a periodic 2D Voronoi tessellation, the main steps are the following:
1. Create the seeds on the original domain.
2. Replicate the original domain 8 times to surround the original domain.
3. Create the Voronoi tessellation on the extended domain.
4. Cut out the original domain from the extended domain.
Reference: https://link.springer.com/article/10.1007%2Fs00466-008-0339-2
