42x60 Horizontal Poster

1
Investigation into Computer AI, and the Math
Behind It.Joseph Pegues, Advisor Dr.
Christopher ElmerShepherd University http//webpa
ges.shepherd.edu/jpegue01/
Packrat
Guardbot
Introduction
Teleport / Backwards
The concept of Packrat was a bot that would horde
items before attempting to attack anyone. Before
attempting to enter a combat state the bot goes
through a list of items. If it has enough then it
is allowed to go into that combat state and
ceases item searching. tem Fdi_SHELLS//FindIt
em("Shells") if (item) index
ITEM_INDEX(item) if (ent-gtclient-gtpers.inventory
index gt ent-gtclient-gtpers.max_shells-85) item
Fdi_CELLS//FindItem("Cells") if
(item) index ITEM_INDEX(item) if
(ent-gtclient-gtpers.inventoryindex gt
ent-gtclient-gtpers.max_cells-150)
The purpose behind the project was to examine
computer artificial intelligence and to show that
artificial intelligence could be applied to many
different projects. To do all this, a copy of
Quake 2, and a computer AI bot, 3zb2, were
acquired. A bot is a multiplayer opponent who
is computer controlled, but designed to act like
a human opponent. The hope was that by examining
3zb2 and altering its code to produce bots with
variations, that it would show that computer AI
can perform a number of different tasks even in a
limited environment. This would imply that by
removing the limiting environment the only
limitation of AI would be the imaginations and
coding skills of the AI creator.
Guardbot is a bot with a job to do. It is given a
specific item in the game to hunt out, and once
it is found the bot stays within short distance
of it. It's objective is to prevent anyone from
getting the item. if(foundRocket ! 1)
Bot_SearchItems(ent) if(zc-gtsecond_target !
NULL ) if((zc-gtsecond_target-gts.origin2 -
ent-gts.origin2) gt 32 !ent-gtwaterlevel) RL
zc-gtsecond_target-gtmoveinfo.start_origin2-ent-
gts.origin2 if(foundRocket1(RL lt lh RL
gt hh) VectorAdd(zc-gtsecond_target-gtmoveinfo.sta
rt_origin,ent-gts.origin,temppos)
Telebort and Backwards are two bots born from
opposite logic patterns. When taking into account
things like shooting and moving to objects, the
bot makes calculations based off its movement
speed. For teleport this speed has been
multiplied by 10, and for backwards negative
one. Interestingly, Teleport exhibits an almost
chaotic behavior because it can never get to
where it wants to be properly. This chaotic
behavior seems to stabilize as more bots are
added to the game.
3ZB2
Conclusion
Santabot
In this project several different logic patterns
for the bots were created. Even in the limited
environment of Quake 2 it is possible to create
AIs that do more than simply shoot at an
opponent. However the bots we're not only limited
by the environment in this project, they were
also limited by 3zb2. With more time and a better
understanding of how Quake 2 works, it would be
possible to create even more bots, possibly even
some with the ability to plan.
3zb2 was originally created by Ponpoko (internet
name), and was acquired from his website
http//ponpoko.tri6.net/3zb2/. The bot has not
had any development for several years, but was
strong enough to allow for modifications that
wouldn't result in crashes over small changes in
the code. Programming wise the bot has no
planning in its thinking patterns. Instead the
bot is reliant on information that it knows to
decide what course of action is best at the
moment. This information is gathered in two ways.
The first is visually by recognizing what is in
front of it. The second is by recorded route
information that is stored in a file outside of
the bot code. While this type of bot is
relatively simple in terms of computer AI used in
video games today, this AI excels in the
simplistic environment of Quake 2. It is capable
of near perfect shooting, always knows where
items are on a map that it has routes for, and
always chooses the best option in a given
scenario.
Santabot is a bot that was designed as a
noncombatant. Commands dealing with firing at
opponents have been removed and replaced with
drop item commands. Thereby giving other
combatants items that the bot is holding onto.
EnemiesAbound /GhostsAbound
EnemiesAbound and GhostsAbound are also created
from opposite logic patterns. EnemiesAbound
believes itself to be constantly confronted by
enemies and so is constantly ready to attack an
opponent. GhostsAbound is a bot that never
believes itself to confronted by an enemy so
never fires its weapon. Interestingly,
EnemiesAbound is slightly smarter than 3zb2, and
at times, even acts more like a human opponent as
opposed to a computer controlled bot.
Bibliography

• Quake 2 was developed by id Software and the game
  box artwork belongs to them. www.idsoftware.com
• 3zb2 was created and owned by Ponoko. It and the
  code behind it are owned by him.
  http//ponpoko.tri6.net/3zb2/
• This poster template was created by MegaPrint,
  and downloaded from http//www.postersession.com/
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