Stephen Flockton







What is my Project?
What is Planning?
Advantages and Disadvantages of Planning.
Description of the Product.
Product Demonstration.
Problems/Successes.
Conclusions from the Project.
This project is about:
 Investigating the application of planners in
video games and academia.
 Discovering the strengths and weaknesses of
planners.
 Evaluating planners as an AI technique
 Creating and testing a planner to gain a better
insight to their application.
F.E.A.R – First Encounter Assault
Recon
Monolith Productions 2005
Stalker: Shadow of
Chernobyl
GSC Game World
Planning is an AI technique where agents create
plans solve their own personal goals.
A plan consists of a list of actions which lead to
the agents goal being solved.
Goal – Kill Target.
Example Plan:
Find Gun
Reload Gun
Fire at Target
A planning system consists of the following:
 A World State Definition
 Actions
 Goals
 Planning Engine
Create Goal
Check
World State
Form Plan
Perform
Action
Goal Satisfied
Update
World State
Plan
Invalidated





Flexibility
Modularity
Believability
Emergent Behaviour
Ease of Debugging




Additional work on initial architecture
Heavy need for optimisation
Not right for every game
Hard to get the frequency of plans just right
This product is a custom built planner which
solves a simple domain model in real time.
The planner is based on a Iteratively deepening
depth first search of world states.
The domain is a simple scenario originally created
by Lee McCluskey.
Goals
Aragorn’s Plan
Length
Aragorn’s Time to
Plan
Boromir’s Plan
Length
Boromir’s Time
to Plan
Get Ring
10 Actions
46.6 seconds
12 Actions
383.4 Seconds
Get Bracelet
5 Actions
0.7 seconds
6 Actions
0.52 seconds
Get Locket
5 actions
0.8 seconds
3 Actions
0.7 Seconds
Kill Troll
3 Actions
Not Measurable
3 Actions
Not Measurable
Kill Golem
3 Actions
Not Measurable
1 Action
Not Measurable
The planner is
in time where M is the mean number of
actions, K is the search depth and N is the number of actions to the
goal.
A custom symbolic World State was created for
the planner.
It is based on Jeff Orkin's Implementation in FEAR
Consists of several enumerated types which make
up an object. All objects can then be represented
symbolically





Initial difficulties with the input language.
Problems with depth first search.
Keeping the execution speed down.
Initial design of World State definition was a
challenge to design.
Long plans take exponential time




World State definition very flexible and
expressive.
Planner can make intelligent plans
Planner can make short plans very fast
Improvement of personal design skills
•AI planning is key to the next set of advances in
video game technology.
•Flexibility and modularity make it ideal for the
game development process.
•I’ve personally learned a lot from this project.

Team based AI planning.

Investigation into wider system integration.

Research into speed increases and heuristics