just a short notice (as i have no definite opinion on how to do it
) :
i like the idea of shared paths ; i.e. get a grid over the zone, and a list of direct LOS connections between them. Then build path grids (and track / flee grids as well, when they are implemented) referencing theses 'safe path grids'
Data storage is not that big (say a few Kb per zone, even if 1 Mb, that does make much as compared to real time LOS computes), and it allows to first define safe paths based on zone geometry, then select a few of these to make a real mob pathing grid. CPU is really low (and limited to boot time) as compared to LOS algs.
Provided nodes will be shared by several mobs, as will segments, data storage shouldn't be that big (nor would maintenance complex) and it allows more flexibility in grid design : we could have pre-set grids (as we have already, i.e. wp1 then wp2 then wp3 ... with all pathing variants we already know), and also extend the system to tracking or fleeing systems
It's nice to have this discussion again