2. AI introduction & a brief history
AI stands for artificial intelligence. AI is intelligence exhibited by
machines or software. The AI was introduced into games in the 70’s
and was mainly in games created by Atari. The game Pacman(1980)
at the time of release, had really advanced AI with the ghosts, with
each ghost programed with path finding logic and their own
personality, Blinky relentlessly follows Pacman and speeds up when
there are only 20 dots left on the screen, Pinky is the ghost that always
trys to catch the player by surprise by going to a tile the the player
might go to, Inky is considered the most “unstable” ghost, as he might
chase the player like Blinky, ambush like Pinky, or just wonder around
randomly like Clyde, Clyde patrols away from the player, based on
where the player is positioned. Because of these personalities, the
ghosts were named “The fathers of game AI”. The first game to
introduce more complex AI since the basic AI introduced by Pac-
man/Atari was the game Dune 2(1992). In this presentation I will be
looking at the relation between AI and hardware available at the
time.
3. Originally AI in games were very limited, and mainly just stood in
one place or walk around until the player was within range of
them, and follow/attack the player until they are killed or the
player is killed. This was the basic programing of enemies for
many years, on games like Super Mario, Legend of Zelda,
Metroid and many more. This is bad AI, as it might annoy the
player too much, as they maybe trying to do part of the game
that requires a lot of concentration in order to perform
correctly. But they programed them like this because the
hardware available at the time, as it could only process 1.79
Mhz, and a cartridge only held 2KiB of memory. So the AI was
competing for space along with, sound, in-game assets and
other lines of code.
In The Legend of Zelda(1986) these
enemies(Octoroc) would patrol a
preset area and would keep patrolling
until Link(the player) is in their line of
sight, then they shoot a projectile at
Link. They keep doing this until Octoroc
is dead or when Link is dead, this is the
most basic, and common AI patterns
for the NES era.
4. AI started thinking more advanced tactics like Half-
life(1998 PC/2001 PS2), flanking the player, using grenades
to force the player out into the open, attacking in groups
and luring the player into a trap. This revolutionized AI in
games, because they gave basic thought patterns to the
AI enemies and then put them in the game. But the
problem is that they still run at the player until the player
or the AI die. The processing power has improved greatly
over the NES games, as processing power for the PS2 was
299Mhz and the CD storage was roughly 680MB, so that
more could be assets can be produced, including: art
assets, sound and more advanced AI coding.
When a Vortigaunt(as dipicted) sees the player, they
will call for backup from other nearby Vortigaunt, they
will often fight in groups, when they take enough
damage, they will retreat and hide, or if cornered by
the player/military, they will attack with melee, in an
attempt to preserve it’s life. Originally(until cut from the
game), they were programed to run away if they were
to see another dead Vortugaunt nearby. These
enemies were programed with the basic “Fight or
Flight” instinct, that most humans/animals possess.
5. Eventually in Farcry 3(2012), they introduced even more
advanced AI, that if they see the player, or see a dead ally,
and the player hides, they will actively seek out the player until
the player is dead or he is dead. Most AI up until this game had
the rule of “If they can’t see the player for (x) amount of time,
stop searching”, even when they see a dead ally next to them,
this is bad AI as this offers no challenge to the player, and can
easily be exploited by the player. This game is possible on the
PS3 as the processing power for the console is 3Ghz and the
disk memory is 9GB. Allowing for AI to do more complex actions,
like remembering previous events and reacting to them
appropriate manner, and alert other guards in the area or set
off an alarm/ambushes/retreats.
If the AI in Farcry 3 find a dead comrade, they will
start searching for the player, they act more like a
human would then their Farcry 2 counterparts.
Farcry 2 AI would often find you straight away and
attacking you relentlessly. Wereas Farcry 3 AI will
only find you if you are within their line of sight, but
can also start looking for you if you make a sound
close to them, so even a silenced weapon can still
alert an other enemy, but only if they are with in
sound range.
6. Other problems with AI
in games
Other problems with AI in games are some times to do with the
other mechanics in the game.
Daniel Brewer said that the biggest challenge with AI in Warframe,
is it’s other mechanic, procedurally generated levels. They don’t
know what the level layout might be, so making encounters that
challenge the player my be hard to pull off, with need of the
pacing to stay the same. Another problem he said was that
players have widely different experiences when it comes to the
game, with people who have really powerful characters or they’re
just starting out, so it can be extremely difficult to balance a boss
battle.
Nicholas Bonardi said that the AI in Rocksmith listen to what the
player is playing in real time, then play along with what ever
instrument/style works best. It uses music theory that is applied to
the AI to make sure it harmonises well with what’s already being
played. Another problem is more then just hitting the notes at the
right time, it’s also trying to make the AI’s sound in the game sound
human.
7. Conclusion
How advanced an AI is, is highly dependent of
the hardware that is available at the time, the
NES could hardly process anything with its
1.79Mhz and could only handle the most basic
AI movment, whereas the current PS4 can
process 3Ghz, and could handle so much more
advanced/varied AI actions. It’s also
dependent on on what other mechanics are
within the game, like procedurally generated
levels could mess with the overall pacing of the
game, breaking the immersion or balancing it
out with the other mechanic in order for it to
work correctly.
8. Future AI prediction
When we reach 50Ghz or higher in a console, it
will make the AI seem almost human, and that
it would be incredibly hard to play against, as
no action done by the AI would ever be the
same. They would even replace the need to
play against other players, as they would
almost think like people. They might even have
matches between 2 AI players and every one
might think they are human players.
