navmesh on gap

                     _____________
                    [             ]
                    [ player size ]
                    [_____________]

______________________           ______________________
                  |   |         |   |
                  |   |         |   |
                  |   |         |   |↑
                  |   |         |   |drawn navmesh
                  |   |         |   |
                  |   |         |↑
                  |   |         | margin
                  |   |
                  |   |↑
                  |   |hole
                  |↑
                  |margin
                  |
    drawn navmesh↑|