Finite State Machines

In this chapter, we'll learn how to implement a Finite State Machine (FSM) in a Unity3D game by studying the simple tank game-mechanic example that comes with this book.

In our game, the player controls a tank. The enemy tanks move around the scene, following four waypoints. Once the player's tank enters the vision range of the enemy tanks, they will start chasing it; then, once they are close enough to attack, they'll start shooting at our player's tank.

To control the AI of our enemy tanks, we use FSM. First, we'll use simple switch statements to implement our tank AI states, then we'll use an FSM framework based on and adapted from the C# FSM framework that can be found at http://wiki.unity3d.com/index.php?title=Finite_State_Machine.

The topics we will be covering in this chapter are the following:

• The player's tank
• The Bullet class
• Setting up waypoints
• The abstract FSM class
• The enemy tank AI
• Using an FSM framework