An overview of AI used in Video Games

1. Artificial Intelligence
And
Video Games
By
Harshal Patil

2. Agenda
 Introduction
 Importance
 Design
 Different game genres
 AI in typical FPS
 Future Scope
 Conclusion

3. WHAT THE ARTIFICIAL
INTELLIGENCE IS ALL
ABOUT ?
 Artificial Intelligence is about making computers
able to perform thinking task that humans and
animals are capable of.
 This “Stuff” is not about making rules as it was in
classical games(E.g. Board games) it’s all about
obeying them strategically in order to defeat
opponent.

4. INCREASING IMPORTANCE
OF AI IN GAMES
 Smartness and complexity of the game entirely depends on
it’s underlying AI.
 Modern users not only demanding extreme graphics, but
also moderate level of opponent intelligence.
 Hence Design and Development Of AI is becoming more
and more significant.

5. SIMULATION OF HUMAN BEHAVIOR
IMPOSSIBLE??
Simulation of actual human behavior would be extremely difficult
if not possible.
Quit often games give a perception of reality
ie: Games appear to have character who are much more
“intelligent” than they actually are..

6. SO HOW DO THEY DO IT THEN??

7. STATE MACHINES
Sometimes non-player characters make decisions using state
machines.
Each non-player character would have a certain number of
states which it will go to when certain criteria are met.
 As the intelligence of the characters increases the decision
trees associated with their actions become more complex.
 The core behavior of the NPCs are defined only by a few
states. The remaining states are for rare circumstances.

8. State machines are inherently predictable to a certain
degree
There is a limit up to which the number of states can
be increased
Defining the transitions between the states is a
difficult task
DISADVANTAGES OF STATE MACHINES

9. Allows various characters on-screen to act
uniquely.
A planning system makes a gaming character
work out what it has to do in order to fulfill an
objective.
In order to achieve a goal, the computer looks
at the situation in which it wants to be, and then
work backwards from it to calculate the best
way of achieving the desired result.
THE PLANNING SYSTEM

10. Different game genres
 Driving
 First Person Shooter(FPS)
 Real-Time Strategy(RTS)
 Sports

11. Adaptive avatar
for driving
Separate game
mode
Basis of all in-game
AI
Basis of “dynamic”
racing line
Drivatar

12.  Two Phase Process:
1. Pre-generate possible racing lines prior to the
race from a (compressed) racing table.
2. Switch the lines during the race to add
variability.
 Compression reduces the memory needs per
racing line segment
 Switching makes smoother racing lines.
Drivatars: Main Idea

13. Segments a1 a2 a3 a4
Racing Table

14. Design
Execution Management
Strategy
Movement
Decision Making
AI MODEL
PhysicsAnimation
Content
Creation
Scripting
AI gets given processor time
Character AI
Group AI
WorldInterface
AI gets its
information

15. The Racing Line Model

16. Minimal Curvature Line

17. FIRST PERSON SHOOTING
GAMES(FPS)
FPS-type games implement layered structure
of the AI system.

18. Navigating through the entirety of the space available to the
NPCs makes the gaming experience more realistic
To address this issue something called “segments” are used.
Segments are a series of points and links, which may or may not
be on or attached to the navmesh.
The AI is free to create paths using these segments just as it
would on a normal navmesh.
The planning system is used to combine different segments,
thus creating paths in space where the characters can move in.
The probable destinations of the moving characters are
calculated in order to avoid collisions
Highly complicated programming involved
NAVIGATING THROUGH VOLUME

19. The NPCs keep checking their environments every
0.5 to 1 sec and respond to the changes using the
planning system
Changes can be identified by using Navmeshes
i.e.: Whenever rigid bodies are removed from the
environment , their corresponding outlines are
identified in the navmesh and the characters are made
to respond accordingly.
HOW IT WORKS ??

20. The general mindset of gamers are changing...
AI acceleration is being welcomed more than ever
Advancements ?......After the state machines and
the planning system , the next step is Online learning
i.e.: Online chatbots such as Jabberwacky learn as a
result of constant online input.(strategies , playing
styles etc)
AI IN GAMES- WHERE NEXT?

21. Simulating actual human behaviour is very
difficult and so games use various forms of
trickery to give an impression of intelligent
behaviour.
The ultimate aim of AI is to improve the
gaming experience and give a realistic feel to
the game.
Various methods including state machines,
planning systems ,online learning etc are used
to run and improve the AI.
CONCLUSION

22. THANK YOU…….