Skip to content

Comment on Voronoi Diagram and Delaunay Triangulation in O(nlog(n)) (2020)parent

Comments

This is pure speculation (graphics algorithms and geometry aren't my strengths), but if you were to do this with a set of 3d points, would we get a relationship between delaunay triangulation (pyramidalization / convex hull?) a relative neighborhood graph, and a minimum spanning tree of 3d points, where combining the RNG and the MST would yield between 1 and 8 edges coming out? (at which point, we could use, say, the numpad for 3d gui widget navigation in the meta-verse in the same way you suggest using 4 cardinal directions for 2d gui representations)

Interesting question! By virtue of being a tree, the MST produces at most 3 edges coming out of any vertex, so this should be the same in 3D. The MST then adds (sometimes) a 4th edge, so, although you could build both graphs in 3D space, you would still end up with 4 edges coming out of any vertex, I think.

In 3D space the Delaunay triangulation would produce a bunch of irregular tetrahedra, so the edges coming out from every vertex would vary between a minimum of 3, and a maximum of 12, if I get it right (ref: [1] :-).

The 3D Voronoi cells are another story... I found some implementation that you can play with to see how it looks [2] [3], each cell is of a shape called "convex polytope". It feels like these cells are packed like each of the sub-cubes of a rubik, but I'm not 100% sure :-) ... if that's true, you could jump from each vertex to the next in at most 26 directions? (hand-waves :-p)

--

1: https://en.wikipedia.org/wiki/Tetrahedron#/media/File:M_tic....

2: https://github.com/BrunoLevy/geogram/wiki/Delaunay3D

3: https://math.lbl.gov/voro++/examples/

AboutSource Built by g1lg1l

Hackerly is an independent reader for Hacker News, built on the public HN API. Not affiliated with Y Combinator.