Personality AI Development A Major Qualifying Project Report Submitted to the Faculty of Worcester Polytechnic Institute in partial fulfillment of the requirements for the Degree in Bachelor of Science In Computer Science By Kien Nhan Jiuchaun Wang Project Advisor Professor Gillian Smith i Abstract This project is about exploring various methods to create game A.I.s with different personalities. A Japanese themed game Action Role Playing Game is also made for testing the A.I.s. We used three algorithms: behavior tree, behavior tree with utility based decision maker, and finite state machine, and made four A.I.s each with personality of: aggressive, bullying, cowardly and tricky. All the A.I.s is put into an NPC monster called Nue in our game: Yokai World and a test were conducted with 16 play testers to see each personality’s recognizability and believability. ii Acknowledgement We would like to thank our project coordinator, Jennifer deWinter for giving us the opportunity to do our MQP project in Japan. We would like to give our thanks to our project advisor, Gillian Smith for providing guidance throughout the time in Japan. We would like to thank Noma Sensei, Ruck Sensei and Takada Sensei for taking care of us during our stay at Ritsumeikan University. We are very grateful for Takada Sensei for giving us a great workspace in his lab in addition to providing us resources to complete the project. iii Table of Contents Abstract ............................................................................................................................................ ii Acknowledgement........................................................................................................................... iii Authorship ...................................................................................................................................... vii List of Figures.................................................................................................................................. ix List of Codes ................................................................................................................................... ix Chapter 1: Introduction ................................................................................................................... 1 Chapter 2: Project Background ...................................................................................................... 3 2.1 Japanese Culture .................................................................................................................. 3 2.1.1 Yokai ............................................................................................................................... 3 2.1.2 Shinto Shrine and Temple .............................................................................................. 7 2.2 Game Artificial Intelligence ................................................................................................... 9 2.2.1 Algorithms ..................................................................................................................... 11 2.3 Personality AI ...................................................................................................................... 16 Chapter 3: Design & Gameplay .................................................................................................... 19 3.1 Experience Goal .................................................................................................................. 19 3.1.1 Different Experience with Different AI Personalities .................................................... 19 3.1.2 Multiple Strategies to Win ............................................................................................ 20 3.1.3 Cultural Experience ...................................................................................................... 20 3.2 Gameplay ............................................................................................................................ 21 3.2.1 Wizard of Legend ......................................................................................................... 21 3.2.2 Binding of Isaac ............................................................................................................ 22 3.2.3 Player and Enemy Controllers ..................................................................................... 24 3.3 Background Design ............................................................................................................. 27 3.4 Player Character Design ..................................................................................................... 31 3.5 Enemy Character Design .................................................................................................... 33 3.5.1 Visual Appearance ....................................................................................................... 34 3.5.2 Personalities ................................................................................................................. 35 Chapter 4: Software and Tools ..................................................................................................... 39 4.1 Unity .................................................................................................................................... 39 4.2 C Sharp ............................................................................................................................... 39 4.3 Spriter .................................................................................................................................. 40 4.4 UtilityAI ................................................................................................................................ 40 4.5 Panda BT ............................................................................................................................ 42 iv Chapter 5: Implementation ........................................................................................................... 43 5.1 Intro ..................................................................................................................................... 43 5.2 Class Design ....................................................................................................................... 43 5.3 Technical Implementations in Unity .................................................................................... 46 5.3.1 Player & Enemy & Camera .......................................................................................... 46 5.3.2 Animation ...................................................................................................................... 48 5.3.3 Collision ........................................................................................................................ 50 5.3.4 Audio Effect .................................................................................................................. 50 5.3.5 Visual Effect .................................................................................................................. 52 5.3.6 Tutorial .......................................................................................................................... 53 5.3.7 Cutscene....................................................................................................................... 54 5.4 Personality ........................................................................................................................... 55 5.4.1 Aggressive .................................................................................................................... 55 5.4.2 Tricky ............................................................................................................................ 70 5.4.3 Bullying ......................................................................................................................... 78 5.4.4 Cowardly ....................................................................................................................... 93 Chapter 6: Testing and Result ...................................................................................................... 98 6.1 Overview ............................................................................................................................. 98 6.2 Population ........................................................................................................................... 98 6.3 Methodology ........................................................................................................................ 98 6.4 Survey ................................................................................................................................. 99 6.5 Challenges ........................................................................................................................ 100 6.6 Result and Analysis........................................................................................................... 101 6.7.1 Recognizability ........................................................................................................... 102 6.7.1 Believability ................................................................................................................. 105 6.7.1 Visuals ........................................................................................................................ 106 Chapter 7: Conclusion