EricBall's Tech Projects

vdub_bobby · November 1, 2006

First thoughts: Enemies apparently won't drop off of ropes unless you are directly underneath them. This means enemies can get stuck on ropes that have walls on either end (i.e., that you can only exit from by dropping).

They just go back and forth forever.

Second thought: When an enemy is in chase mode and hits a wall, currently it moves in a random direction, changing state to hunt, correct? A suggestion: if an enemy hits a wall and is also on a ladder, move him up/down towards the player (if the player is above/below) and leave him in chase mode. Same when moving up/down on a ladder.

Take this situation, for example:

				P
	  =-----------=
 E	   =|		 |=
-----------|		 |-----------

- are floors, | are walls, = are ladders.

P is the player

E is the enemy, chasing P to the right. When he hits the wall (and ladder), 80% of the time he just turns around.

The behavior appears to be the same when reaching the top/bottom of a ladder.

Third thought: this is a wild, completely out-of-the blue idea, but have you considered, or tried, implementing a Pac-Man style logic? Have the enemies chase the player on a timer; when the timer elapses, have them head towards a corner for a short period of time before starting the chase timer again. Some variety of this might be very nice, especially if the behavior was slightly different for the different enemies (like in Pac-Man): different enemies might have different length timers, they might chase directly towards the player or towards a spot ahead/behind the player, etc.

EricBall · November 1, 2006

First thoughts: Enemies apparently won't drop off of ropes unless you are directly underneath them. This means enemies can get stuck on ropes that have walls on either end (i.e., that you can only exit from by dropping). They just go back and forth forever.

Hmm... interesting point; I hadn't thought of that. I can certainly add logic for the enemy to try dropping off a rope when they are in hunt mode and they reach the end of the rope. (Though there still could be a problem if the ends of the rope have rock/dirt under them.)

Second thought: When an enemy is in chase mode and hits a wall, currently it moves in a random direction, changing state to hunt, correct? A suggestion: if an enemy hits a wall and is also on a ladder, move him up/down towards the player (if the player is above/below) and leave him in chase mode. Same when moving up/down on a ladder.

Yeah, I have a sneaking suspicion that the enemies are kicking into hunt mode too easily. The enemies are still dumb in your switchback level 'cause they kick into hunt mode which takes them away from the player. On a related note, falling kicks the enemy out of hunt mode which can cause other issues.

Third thought: this is a wild, completely out-of-the blue idea, but have you considered, or tried, implementing a Pac-Man style logic? Have the enemies chase the player on a timer; when the timer elapses, have them head towards a corner for a short period of time before starting the chase timer again. Some variety of this might be very nice, especially if the behavior was slightly different for the different enemies (like in Pac-Man): different enemies might have different length timers, they might chase directly towards the player or towards a spot ahead/behind the player, etc.

Haven't considered (or tried) anything like that. I don't know how well it will work, though there are four corners and four enemies....

vdub_bobby · November 1, 2006

Second thought: When an enemy is in chase mode and hits a wall, currently it moves in a random direction, changing state to hunt, correct? A suggestion: if an enemy hits a wall and is also on a ladder, move him up/down towards the player (if the player is above/below) and leave him in chase mode. Same when moving up/down on a ladder.

Yeah, I have a sneaking suspicion that the enemies are kicking into hunt mode too easily. The enemies are still dumb in your switchback level 'cause they kick into hunt mode which takes them away from the player. On a related note, falling kicks the enemy out of hunt mode which can cause other issues.

I did notice, though, that the switchback level works *much* better now than it did before.

Another note: I have seen some really weird behavior, similar to what I noted above, like this:

	P
------------



------------------=   E
			 |--------

Sometimes in this situation the enemy will do this forever:

1. move L to the ladder

2. move U to the top of the ladder, then

3. move R, fall down one square, then

4. goto 1.

It's as if, rather than moving randomly when reaching the top of the level, the enemy perversely moves purposely away from the player. This seems to happen more often (only?) when two enemies are involved; maybe the routine to keep them from overlapping is driving this somehow, but it sure is strange looking to see one or more enemies moving in this tight little circle forever.

Third thought: this is a wild, completely out-of-the blue idea, but have you considered, or tried, implementing a Pac-Man style logic? Have the enemies chase the player on a timer; when the timer elapses, have them head towards a corner for a short period of time before starting the chase timer again. Some variety of this might be very nice, especially if the behavior was slightly different for the different enemies (like in Pac-Man): different enemies might have different length timers, they might chase directly towards the player or towards a spot ahead/behind the player, etc.

Haven't considered (or tried) anything like that. I don't know how well it will work, though there are four corners and four enemies....

Off the top of my head, the benefits:

You don't have to worry too much about enemies getting stuck, since they will switch to "head to corners" mode at some point.

You don't have to worry about the enemies making transitions from hunt to chase or vice versa at the wrong times, which seems to be a vexing issue. :lol:

I really like the hunt/chase idea and, ultimately, I think if/when you can get it working right it will be better than a Pac-Man-style AI - but it might be interesting to see what the ghosts can do.

EDIT: My final thoughts, for now: This AI is much better than the old AI - except for a few glitches (mentioned above) it is very good. :ponder: