this is my 2 cents 8o)
what if monsters would only spawn if they were not in the field of view of any player?
this would solve 2 problems at once, first the monsters wouldn\'t be seen apearing from nowhere (just make the spawn areas near somewhere that could explain the apearing of the monster
and it would also solve the problem o camping, all the players includin the ones not in the group should be all facing the other way for for the monster to spawn, this would automaticly distribute the players, as they would have to go else where to find mosnters
and make the monster test for looks after random times, they check to see if anybody is seeing, it will spawn or not and randomize the time, after the random time period passes it checks again, and so on
the random time would make the campers frustrated, as they would not know when to look there again, if they look at the wrong time the monster would not spawn and they would risk the random time to be reset to a long time
and also to recycle monsters the same strategy with few alterations could be used to the disapearing of the monsters if they wondered for more than N minutes without being seen by a player he would disapear, as for the monsters stucking, perhaps divide the world in several smal areas ( 2x2 meters squares for example) if the monster stay on one square for more than N minutes he would be \"aimed\" to the previus square and go in that direction, and if he still don\'t manage to reach that square in less than Y minutes its colsion detection, perhaps based on a cylinder , would get more and more insensitive, smaler radius perhaps, untill themonster has its colision detection deactivated if necessary to reach th previus 2x2 meters square
ofcourse that the time the monster stay in the same place would not count if he is attacking
I am just not sure of the processing cost of checking the field of views of several players, perhaps a proximity or motion detection could be used instead