After quite a bit of experimentation , I don't think building navmeshes during runtime will be a good idea for my game. I need a high level of precision (.1 or smaller cell size), and a pretty large area to map at a time.... it ends up taking around 30 seconds or so, which isn't too surprising.
The sad thing is I don't even want to build navmeshes at runtime... my world is pretty static in this way, and if I could build the navmesh in editor that would be the best bet, since it would mean no recasting needed at all!
Of course, the problem is I can't just build a massive navmesh of my entire world, that would be ridiculous. My original solution was going to be to build a chunk of navmesh at a time, since my world is split into "chunks" / scenes... however, using Unity's base navmesh system, of course this results in separate, detached navmeshes.
And of course, the problem is the same with A* Pathfinding project. However, this code is "open", so I think finding a solution here would be easier...
Let's say I have a bunch of navmesh chunks. I need to stitch these together. Problem is, it won't be easy, since there will be overlapping bits and alll sorts of other junk... for example, a rock may overlap onto another cell, so when the stitching happens, this would need to be accounted for...
Any thoughts? Ideas? Other solutions that don't involve super complex mesh stitching? xD
EDIT: A 500x100x500 area (which is still too small, since I need npc's to be able to walk pretty far) takes 39 seconds to scan. Makes sense since it's a complex world, so I am going to go towards the idea of building it during edit time.