Is there a Fortran library of some sort for geometric search algorithms, something like ArborX?
Don’t know if they are what you are looking for but implementations of Javier Bonet’s Alternating Digital Tree (ADT) algorithm as well as a KDtree implementation are available at
These are used a lot in CFD to find nearest neighbors, surface intersections etc.
Edit
A copy of Bonet’s IJNME article “An Alternating digital tree algorithm for 3D geometric searching and intersection problems” is available here:
Thanks a lot. I can definitely build on these.