If object is too big iteration over all tiles covering it can take too much
time. Limit bounds to a square around a player position to cover only tiles
that will be present in navmesh based on max tiles number option.
Each object is associated with a set of tiles its present in. Culling can
reduce this set but it has to be update when bounds change position. Do this
in TileCachedRecastMeshManager::setBounds updating the set and adding/removing
objects to the corresponding CachedRecastMeshManagers.
Add special loading progress bar.
It should be fast enough to not keep loading screen for noticably long but
will provide better pathfinding for actors inside interior cells.
When distance between start and end point is greater than max radius of area
possibly covered by navmesh there is no way to find path via navmesh. Also if
distance is greater than cell size navmesh might not exists withing mentioned
area because cell is not loaded therefore navmesh is not generated. So minumum
of these values is used to limit max path distance. Assuming that path
actually exists it's possible to build path to the edge of a circle. When
actor reaches initial edge path is built further. However it will not be
optimal.
