“…The inaccessible point is defined as whether there is an inaccessible buildin other non-passable road, that divides the rectangular area into at least two parts target point and the current node as the vertices, and the target point and the point belonging to different areas, as shown in Figure 15. In Figure 15, in the process of searching from the starting point (22,5) to th point (13,32), the neighborhood passing point (17,11) of a certain point in the rec area formed by the neighborhood passing point and the target point, there is a b wall, (13,19) to (17,19), to divide the rectangular area into left and right parts. Th borhood pass points (17,11) and the target points (13,32) are divided into two unco areas in the rectangular area, then the spatial accessibility of the pass points in the gular area is updated and marked as unreachable, that is, the light green nodes in In Figure 14, the green invalid search area in the invalid search space is ca semi-closed structure space.…”