anytime I think about sight or scent I start wandering off into
spatial models other than the traditional rooms-with-exits.
simple sight problem: in Enhanced, there's a straight hallway split
into three locations. Bob the guard occasionally wanders in the hall,
but you don't see him unless you're actually in the same "location".
Fixing this is doable, but awkward, and I start wishing for a spatial
model that's more physically based, like nethack or Doom, instead of
the conceptually-based spatial model of text adventures.
Perhaps this is an argument against following this particular line of
So, say the bear only interacts with objects in the current location.
Smell and sound might leak to adjacent locations, but that's it.
Moving around is based mostly on knowledge and memory rather than
Objects in the bear's world include
things known to be food
things known to be non-food
things whose food-status is unknown
obstacles to food, like containers
Maybe include animate food? Well, this introduces a whole slew of
other problems. Maybe it would be easier to start by building a
herbivore like a rabbit or a horse, instead of a bear.
anyone interested in this type of development should probably look at
what's going on in simulating artificial life. _Artificial Life_ /
Steven Levy, 1992. Plus random conferences and journals on the topic.
well, that's my ramble for today.
| One .sig to rule them all, one .sig to find them... |
| One .sig to bring them all and in the darkness bind them |
| The Grim Reaper (Reaper of Souls, Stealer of .sigs) |
| scy...@u.washington.edu |
Yay, glad someone is taking up the idea. Since it was my suggestion, I'd
be glad to toss in my thoughts.
>let's say we're going to create the aforementioned bear. Well, the bear will
>wander around the game, trying to fulfill a couple personal goals. What
>should they be? I expect for a bear, eating and sleeping are going to be
>its main priorities. This means we'll have to keep track of how tired
>and how hungry the bear is. Perhaps its reaction to the player as well.
A fairly sensible set of goals. A bear basically has a few behavioral
patterns that I know of. (Recapping your thoughts and expanding them)
- Eat when hungry (berries, fish, honey, small, careless animals, garbage
can raiding, tearing open cars to get at food inside.
- A bear will smell food unless it is in a truly sealed container, like
potato chips in an unopened bag. A cooler is not a sealed container.
- A bear sleeps during the day, I guess. I'm not too sure whether they
are nocturnal or not. Any bears out there care to answer that one?
-Bears will sleep in a cave, if they know of one. They have also been
known to sleep in a 'nest' hollowed out of the ground in a
shaded/bushy/secluded area. (Again, I'm going off layman knowledge here,
someone correct me if I'm wrong.)
-A bear will make claw marks on trees in its territory to warn other
-A bear fed by hand is likely to eat the hand that feeds it, unless
-A bear fed in one location will remember that location/person as a
source of food. This is the reason for the 'Do not feed the bears' rule
at parks. Bears return to the camping grounds looking for more food, and
their contact with idiot tourists often winds up with a mauled tourist.
-A bear is frightened, rather than annoyed, by loud noises.
-A frightened bear will retreat to a safe spot, his cave, or possibly up
-A frightened bear will lash out at anything that approaches it.
-A bear will chase you if you run from it, thinking you a small, careless
-A bear that has treed a small, careless animal, will shake the tree to
try and dislodge 'lunch'.
-A bear will go after the first food source that presents itself,
ignoring others until finished with the first.
-A bear eating may see an approaching animal as a competitor for the food
source, and attack.
-An attacking bear will stand on its hind legs, to intimidate the
opponent, then charge on all fours. (Again, mere layman knowledge. I'm
no behavioral scientist.)
-A frightened bear will eventually stop being frightened, if the source
of that fear goes away.
-An angry bear will calm down if left alone, but will be quicker to anger
in the near future.
Well, even if that's not an entirely accurate or complete (nowhere near
complete) summary of bear behavior (keeping in mind there are different
kinds of bears with different behaviors and personalities.) it'll do for
now, until we 'program' some of it. Any other suggestions, coding
attempts (in pseudo code)?
< I W In the jungle of the big city, a predator stalks one | ~~\ >
< GO SOFT he considers easy prey, a blind student. Feel the fear | /~\ | >
We started, similar to what you have done, by outlining the important
behaviors and emotional responses we wanted the cat (Lyotard) to display.
If you want to find out more about this project for ideas in building
a bear, you can check out a few of our papers on the subject via our
The two most relevant are probably:
"Integrating Reactivity, Goals, and Emotion in a Broad Agent"
"An Architecture for Action, Emotion, and Social Behavior"
In both, the emphasis is in our particular agent architecture, but
they also each talk about Lyotard and the process we went through
in building him.
Also, you can get a trace of Lyotard at:
Hope this is of some use.
: OK, chaps, here is Artoris. He's a bit quickly hacked together, but he
: works, and fulfills the spec. He works in the context of my own ADE,
: and so to understand the code you need to understand a bit about how
: that works. You'll see that it's LisP. If you have trouble with it, it
: started off in Cambridge LISP but is in the process of being ported to
: XLISP. Artoris works in the XLISP version, but uses a lot of Cambridge
: LISP idiom.
Cute. But, how can we run it? Can we ftp your system?
what do we need to consider to handle the 'smells for food' unless in
What about the 'scratching trees to mark his territory?'
As I read A. the bear, he really doesn't have a home. (just the last
place he slept) is this necessary?