Book Image

Unity 2017 Game AI Programming - Third Edition - Third Edition

Book Image

Unity 2017 Game AI Programming - Third Edition - Third Edition

Overview of this book

Unity 2017 provides game and app developers with a variety of tools to implement Artificial Intelligence. Leveraging these tools via Unity's API or built-in features allows limitless possibilities when it comes to creating your game's worlds and characters. This third edition with Unity will help you break down Artificial Intelligence into simple concepts to give you a fundamental understanding of the topic to build upon. Using a variety of examples, the book then takes those concepts and walks you through actual implementations designed to highlight key concepts, and features related to game AI in Unity 5. Further on you will learn to distinguish the state machine pattern and implement one of your own. This is followed by learning how to implement a basic sensory system for your AI agent and coupling it with a Finite State Machine (FSM). Next you'll learn how to use Unity's built-in NavMesh feature and implement your own A* pathfinding system. You will then learn how to implement simple flocks and crowd's dynamics, key AI concepts. Moving on, you will learn how to implement a behavior tree through a game-focused example. Lastly, you'll combine fuzzy logic concepts with state machines and apply all the concepts in the book to build a simple tank game.
Table of Contents (10 chapters)

Touching is believing

The next sense we'll be implementing is Touch.cs, which triggers when the player tank entity is within a certain area near the AI entity. Our AI character has a box collider component and its IsTrigger flag is on.

We need to implement the OnTriggerEnter event, which will be called whenever another collider enters the collision area of this game object's collider. Since our tank entity also has a collider and rigid body components, collision events will be raised as soon as the colliders of the AI character and player tank collide.

Unity provides two other trigger events besides OnTriggerEnter: OnTriggerExit and OnTriggerStay. Use these to detect when a collider leaves a trigger, and to fire off every frame that a collider is inside the trigger, respectively.

The code in the Touch.cs file is as follows:

using UnityEngine;

public class Touch : Sense...