You might not be aware of the fact that you most likely have been using the algorithm we’re discussing here – at least if you’ve ever worked in 3D. Quadtrees (and their relatives, KD-Trees and Octrees) are used to accelerate point queries (ever used pcfind() or nearpoints() in Houdini?), make rendering faster (ever waited for “building raycast accelerator” to finish?) or to compress images. Also they are mesmerizing to look at.
This one is a rather brute force approach for a problem we had to solve on a recent job: Finding a path through a bunch of obstacles. Admittedly what we implement here isn’t a very sophisticated algorithm, but its power lies in its simplicity: It will find a path as long as it’s got enough points available.