Pathfinding is going to be trouble

Pathfinding is a pain in any game.. Have a good week off though.

This only interests me because I am a second year CS student and I was thinking about trying to eventually get involved in game programming.  I believe Zer meant paths for objects with AIs (monsters, guard NPCs, et. al.) rather than for players, judging by how he said it was difficult.  While clicking a tile away does, technically, involve pathfinding it is a simple procedure of finding the shortest relative path with a shortest path algorithm and executing it.

When an AI is having to evaluate threats, go after a moving target, change course midstream and deal with a changing surroundings, things indeed get much hairier.  This is usually because the destination changes or the path becomes blockes by one or more dynamic objects.  NPCs move in a loop, at least moving ones do, within a confines.  That isn't as hard as a monster AI, which also has to determine a destination as well as do the above with pathfinding.

To clarify again, what I was referring to is what event (if it is event-driven?) triggers the monster AI 'code' or will trigger it: every time the object moves a tile, when the map nearby changes or when it encounters a new object or every tick?

A personal guess in terms of difficulty:

player  pathfinding < NPC pathfinding (merchants in a closed off area) << monster AI pathfinding/threat evaluation

Finding an efficient algorithm to do this cannot be easy, does anyone know if he is going to use A-star pathfinding?  I was looking at this stuff awhile back when I was toying with the idea making a pacman game.

Icic thanks Aaron la~

Cool... Some nice stuff there.