This block uses D3 version 4’s d3-force and d3-voronoi to compute the Voronoi diagram for a set of nodes in a force layout as they are dragged around.
For a simple demonstration of the Voronoi diagram, see this block.
For a version of this block without the Voronoi diagram, see this other block.
For more information on the various forces available in D3 v4, see Steve Haroz’s d3-force testing ground.