1. Analysis and Understanding
CIS 488/588
Bruce R. Maxim
UM-Dearborn
11/18/2018

2. AI Engineering Analysis Understanding
Aims to investigate the game environment, game engine, and platform
Design document is used as input when game engine and AI are developed in parallel
Understanding
High-level requirements and goals to analyze the problem at hand, irrespective of the game engine and just from the perspective of AI development
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3. Write It Down
It is vital to spend time writing down your thoughts on all problems tackled
You want to avoid wasting time revisiting closed issues
Add this stuff to the development notes (electronic with backup is probably better than paper)
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4. Big Picture - 1
Platform – SW and HW supporting development (game world and game engine)
Task – conceptual explanation of goals of AI within platform (understanding local info to prevent collision)
Information – collection of data from platform to achieve task (environment structure and detail)
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5. Big Picture - 2
Input – subset of available info converted usable format (input + output = solution scaffolding)
Output – possible player actions combined with platform to form outcome
Context – implicit state containing info about task, defining effect of outputs and restricting inputs
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6. Big Picture - 3
Problem – the description of AI module capable of mapping information from input to output (e.g. avoiding individual obstacles)
Solution – particular AI component capable of resolving the problem, obtaining the desired outcome while respecting the requirements (e.g. steering behavior)
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7. Analysis Phase Tackles common principles not particular scenarios
Requires studying:
General task (universal ability AI is to provide)
Platform (aspects of design affecting the task)
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9. Assumptions
List the facilities of platform that AI can rely on and are taken into account during specification
Often sufficient to describe human player interfaces
Game engine is usually frozen
Developer must decide how much of the platform to expose to the AI and at what level it should be integrated
Reuse code whenever practical
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10. Restrictions Aspects of design or software that affect task at hand
Affect the problem, not its specification
Taken into account during understanding phase that describes the problem
Describe the parts of the game engine that make the problem hard to solve
Terrain structure may prevent certain types of movement or prevent gathering perfect info
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11. Guidelines
Design and platform aspects to be taken into account during that application phase
Procedures that are to be followed very closely throughout the process
Hard to identify specific AI guidelines before game development actually begins
Much like agile development any structure added to the process is good, not matter when it is added to the development process
11/18/2018

12. Understanding
Focuses on one particular task and describes how a solution works
Relies on:
Goals (high-level outcome description discussing what AI needs to achieve)
Requirements (development team members requests that need to be accommodated in problem description)
Restrictions (implicit aspects of platform that affect problem solution)
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14. Criteria and Outcome Describe resulting behavior first
Highly desirable to have a well-defined problem outcome
If goals are incomplete or uncertain AI engineering is difficult at best
An ordered list of high-level problem specific criteria is suitable for this
These criteria can be used to evaluate the quality of a problem solution
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15. Sample Criteria Animats take no steps that cause collisions
Allow contact with obstacles only when animat is not moving
Restrict animat turns to 20 degrees/second when no obstacles are with in 4 steps
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16. Problem Decomposition
Understanding phase decomposes single outcomes into sequences of actions needed to solve particular problems
This makes problems more explicit and easier to solve
It is often possible to determine what needs to be done based on observation of human behavior
Sometimes description needs to be done by listing scenarios and their restrictions
11/18/2018

17. General Advice
The role of the understanding phase is to describe problems in detail, not solutions
This allows domain experts to write problem descriptions with a little training and this will allow for better communication with developers
Caution, since lists of criteria are written in natural language they will be ambiguous
Ambiguity allows both requirement misinterpretation and flexibility in solution creation
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18. Tobor Obtains basic information from the environment
Tactile sensors are used to detect contact with obstacles
Stops when collisions occur and machanically turns around
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