How does WHCA* work? I see sometimes the object would wind back and forth and wait for a choking point to clear. I understand that some nodes that are blocked at the certain time will not be pushed onto the open list. The rest seems to be familiar. But how come a best node candidate "hop" would happen that the best node will return to some previous positions? What are the principles/techniques used? All it seems like a magic to me.
Thanks
Jack