Zombie AI not pointing towards the player?

My zombie isn't working and not quite sure what the problem is. I got this script off of a website and it was working before but now it isn't.

Here is the error: NullReferenceException: Object reference not set to an instance of an object Zombie.FixedUpdate () (at Assets/scripts/Scene5 (level 1)/Zombie.js:18)

Here is the script:

Code (JavaScript):

1.     #pragma strict
2.    
3.     var VisionDistance : float = 200;
4.     var MovementSpeed : float = 2;
5.     var Health : int = 3;
6.    
7.     function FixedUpdate () {
8.     // Get the Player object
9.     var player : GameObject = GameObject.Find("Player");
10.     var characterController : CharacterController = GetComponent(CharacterController);
11.    
12.     // Get the position of the Zombie's eyes
13.     var eyePosition : Vector3 = transform.position;
14.     eyePosition.y += characterController.height;
15.    
16.     // Get the difference between the player and the Zombie positions
17.     // This creates a direction vector pointing in the direction of the Player.
18.     var lookDirection = player.transform.position - eyePosition;
19.     lookDirection = lookDirection.normalized;
20.    
21.     // Only look for the player or objects that are part of the scenery (terrain, buildings, etc.)
22.     var layerMask : int = 1 << LayerMask.NameToLayer("Player") | 1 << LayerMask.NameToLayer("Default");
23.    
24.     // The direction the Zombie will move, defaults to standing still
25.     var movementDirection : Vector3 = Vector3.zero;
26.    
27.     // hitInfo will contain information about what the Zombie can see.
28.     var hitInfo : RaycastHit;
29.     if (Physics.Raycast(eyePosition, lookDirection, hitInfo, VisionDistance, layerMask)) {
30.     // If the Zombie can see the Player move toward them.
31.     if (hitInfo.collider.gameObject == player) {
32.     movementDirection = lookDirection;
33.     movementDirection.y = 0;
34.     movementDirection = movementDirection.normalized;
35.     }
36.     }
37.    
38.     // Face and move in the chosen direction
39.     if (movementDirection != Vector3.zero) {
40.     transform.rotation = Quaternion.LookRotation(movementDirection, Vector3.up);
41.     }
42.     characterController.SimpleMove(movementDirection * MovementSpeed);
43.     }

Any help is appreciated.

 

It's not finding the player object you're looking for on line 9, so when it tries to use player.transform.position, it returns null.
Make sure you have a character in the scene named Player, or get a reference to the player character some other way and use that. =)

 

How else can I get a referance to the player?

 

Well, you could change this line:

Code (JavaScript):

1. var player : GameObject = GameObject.Find("Player");

Just replace the name Player with whatever name your player character has.

Alternatively, you could do this:

Code (JavaScript):

1. var player : GameObject;

And assign the player object in the inspector.

 

The player object is called Player. Oh and, the zombie is a prefab to be spawned.