Enemy Script Unity 3d Game Development Tutorial - Learn & Build IGI 3 Game Clone - Unity Game Engine

Introduction

In this tutorial, we will create an enemy script for a 3D game using Unity, specifically aimed at developing a clone of the classic IGI 3 game. This guide is perfect for aspiring game developers looking to enhance their skills in Unity game engine and learn how to implement enemy behavior in a third-person perspective game.

Step 1: Setting Up the Enemy Script

1. Create a New Script

   • In Unity, right-click in the Project window.
   • Select Create > C# Script and name it EnemyScript.

2. Open the Script

   • Double-click EnemyScript to open it in your code editor.

3. Define Variables

   • Add the following variables at the top of the script to define the enemy's properties:

     public float speed = 3.0f;
     public float detectionRange = 10.0f;
     public Transform player;
     

4. Initialize the Script

   • In the Start method, initialize any necessary components such as the player's transform:

     void Start() {
         player = GameObject.FindWithTag("Player").transform;
     }
     

Step 2: Implementing Enemy Detection

1. Create the Update Method

   • Add the Update method to continuously check for the player's presence:

     void Update() {
         float distance = Vector3.Distance(transform.position, player.position);
         if (distance < detectionRange) {
             PursuePlayer();
         }
     }
     

2. Define the PursuePlayer Method

   • Create a method to handle enemy movement toward the player:

     void PursuePlayer() {
         Vector3 direction = (player.position - transform.position).normalized;
         transform.position += direction * speed * Time.deltaTime;
         transform.LookAt(player);
     }
     

Step 3: Adding Animation and Effects

1. Integrate Animator

   • Ensure that your enemy has an Animator component attached.
   • Create animation states for idle and walking.

2. Modify the PursuePlayer Method for Animation

   • Update the enemy's animation based on its speed:

     void PursuePlayer() {
         // Same as before...
         Animator animator = GetComponent<Animator>();
         animator.SetBool("isWalking", true);
     }
     

3. Return to Idle State

   • Add logic to return to the idle animation when the player is out of range:

     if (distance >= detectionRange) {
         animator.SetBool("isWalking", false);
     }
     

Step 4: Testing the Enemy Behavior

1. Attach the Script to Enemy GameObject

   • Drag and drop EnemyScript onto your enemy GameObject in the Unity hierarchy.

2. Set Player Tag

   • Ensure your player GameObject is tagged as "Player" for detection to work.

3. Adjust Parameters

   • In the Unity inspector, set the speed and detectionRange values to fit your gameplay needs.

4. Playtest the Game

   • Enter Play mode in Unity and observe the enemy’s behavior as it detects and pursues the player.

Conclusion

In this tutorial, we successfully created an enemy script that allows an enemy character to detect and pursue a player in a 3D environment using Unity. Key points include setting up the script, implementing detection and movement, adding animations, and testing the functionality in Unity.

As a next step, consider expanding the enemy's behavior by adding attack mechanisms or different states such as patrolling. Happy game developing!