2D AI Movement using 'transform.position +=' C#

I'm making a 2D TopDown AI system that moves the enemy to the player. The problem is that the enemy constantly moves to the bottom left corner.
Here's my code:

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class ZombieAI : MonoBehaviour {
5.  
6.     float targetDistanceX;
7.     float targetDistanceY;
8.     Vector3 velocity;
9.     public Entity zombie;
10.     public Entity player;
11.     Rigidbody2D rb;
12.  
13.     // Use this for initialization
14.     void Start () {
15.  
16.         rb = GetComponent<Rigidbody2D> ();
17.  
18.     }
19.    
20.     // Update is called once per frame
21.     void FixedUpdate () {
22.        
23.         targetDistanceX = player.transform.position.x - transform.position.x;
24.         targetDistanceY = player.transform.position.y - transform.position.y;
25.  
26.         velocity = new Vector3 (targetDistanceX , targetDistanceY, 0);
27.  
28.         transform.position -= (velocity.normalized * zombie.speed * Time.fixedDeltaTime);
29.  
30.  
31.  
32.     }
33.  
34. }

If anyone knows the problem, feel free to reply

Kind regards,
Tom

 

You might want to use Vector2.MoveTowards as currently what you are doing is extracting the target position from your current position which will always move you towards 0.0 (which is the bottom left).

 

I tried it, but now it doesn't move at all(if I push it, it does move btw).

 

and we're going to use our psychic powers to see the code you tried to use?

you could just use "+=" instead of "-=" so you're applying the right direction... (which is what Timelog was referring to I think)

just going to comment on this... AIs make decisions, they don't perform the concrete movement of anything to anywhere. If you make sure you break up how you think about what the scripts are doing you'll, by extension, build better script architecture.

AIs take input and make decisions.
Pathfinders work out a path from point a to b.
Movement/Locomotion/whateverYouWantToCallIt scripts actually move the object.

similarly
Players make decisions
InputController scripts handle the input
Movement/Locomotion/whateverYouWantToCallIt scripts actually move the object. <--- it's the same line as above code reuse!