Game Development Reference
Create three more copies of the NavMesh, and spread them out in a similar manner,
so that all corners of the map are covered. We want to make sure that none of
our pylons fall into the boundary lines of another pylon, as the map will not build
correctly. However, it is perfectly fine if the bounds for the pylons overlap.
Rebuild paths by selecting the Rebuild Paths button at the top of the editor. If you
laid your pylons down correctly, you should see a series of polygons, illustrating the
walkable area that your AI pawn may traverse, along with a yellow line (it appears as
the thickest set of lines, shaped like a square in this figure) connecting the pylons, as
they can be seen by line-of-sight.