Question 2D enemy AI 4 directional attack

Im trying to create a 2D rpg game and I already have an enemy that detects and chases the Player whenever the Player is within range. What I want to happen is for the enemy to play an attack animation (left, right, up or down) depending on where the player is. Any help will be appreciated .


Heres the movement script for my enemy if it helps (its from a youtube tutorial i watched):

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class EnemyAI : MonoBehaviour
6. {
7.     private float angle;
8.     public float speed;
9.     public float checkRadius;
10.     public float attackRadius;
11.  
12.     public bool chasing;
13.  
14.     public LayerMask whatIsPlayer;
15.  
16.     private Transform target, enemy;
17.     private Rigidbody2D rb;
18.     private Animator anim;
19.     private Vector2 movement;
20.     public Vector3 direction;
21.  
22.     private bool isInChaseRange;
23.     private bool isInAttackRange;
24.  
25.     private void Start()
26.     {
27.         rb = GetComponent<Rigidbody2D>();
28.         anim = GetComponent<Animator>();
29.         target = GameObject.FindWithTag("Fighter").transform;
30.     }
31.     private void Update()
32.     {
33.         anim.SetBool("isRunning", isInChaseRange);
34.  
35.         isInChaseRange = Physics2D.OverlapCircle(transform.position, checkRadius, whatIsPlayer);
36.         isInAttackRange = Physics2D.OverlapCircle(transform.position, attackRadius, whatIsPlayer);
37.  
38.         direction = target.position - transform.position;
39.         angle = Mathf.Atan2(direction.y, direction.x) * Mathf.Rad2Deg;
40.         direction.Normalize();
41.         movement = direction;
42.         if(chasing)
43.         {
44.             anim.SetFloat("Horizontal", direction.x);
45.             anim.SetFloat("Vertical", direction.y);
46.         }
47.  
48.     }
49.  
50.     private void FixedUpdate()
51.     {
52.         if(isInChaseRange && !isInAttackRange)
53.         {
54.             MoveCharacter(movement);
55.         }
56.  
57.         if(isInAttackRange)
58.         {
59.             rb.velocity = Vector2.zero;
60.  
61.         }
62.     }
63.  
64.     private void MoveCharacter(Vector2 direction)
65.     {
66.         rb.MovePosition((Vector2)transform.position + (direction * Time.deltaTime));
67.     }
68. }
69.  

 

Sounds great! The necessary parts will be:

- make 4 separate animations for each direction (start with perhaps ONE just to prove it works)
- based on the player vs enemy position, choose which animation to play
- play it
- do any other damage bookkeeping.

Which parts are you struggling with?

How to report your problem productively in the Unity3D forums:

http://plbm.com/?p=220

This is the bare minimum of information to report:

- what you want
- what you tried
- what you expected to happen
- what actually happened, especially any errors you see
- links to documentation you used to cross-check your work (CRITICAL!!!)

 

I've done the first step (make 4 seperate animations). Now I'm struggling with how to write the code that tells whether the player is right, left, up or down of the enemy.

I can get the enemy to attack in 1 direction but only 1.

My Player's attack animations are based on anim.SetFloat("LastHorizontal", Input.GetAxisRaw("Horizontal")) and anim.SetFloat("LastVertical", Input.GetAxisRaw("Vertical")) so I thought I could do the same with the enemy but I realized I cant since its Input. And I dont know what the alternative is or how I should code it.

 

The easiest way is to see which axis (X or Y) is larger magnitude, and based on that larger axis decide which way.

Code (csharp):

1. // fill these in appropriately:
2. Vector3 playerPosition = ....
3. Vector3 enemyPosition = ...
4.  
5. // enemy first in subtraction means "how does the player go TO the enemy?"
6. float deltaX = enemyPosition.x - playerPosition.x;
7. float deltaY = enemyPosition.y - playerPosition.y;
8.  
9. if (Mathf.Abs( deltaX) > Mathf.Abs( deltaY))
10. {
11.   // must be left or right since deltaX is greater
12.   // if (deltaX < 0) it is left...
13.   // if (deltaX > 0) it is right...
14. }
15. else
16. {
17.   // must be up or down since deltaY is greater/equal
18.   // if (deltaY < 0) it is down...
19.   // if (deltaY > 0) it is up...
20. }

Obviously doesn't handle player / enemy at the same location.

 

Thanks a lot. I've been stumped for a couple days with this one. I'll test it out later

 

Yo, just an update, It works. Thanks again for the help man.

I did it like this:

Code (CSharp):

1. if(isInAttackRange)
2.         {
3.             rb.velocity = Vector2.zero;
4.             Vector3 playerPosition = target.position;
5.             Vector3 enemyPosition = transform.position;
6.  
7.             float deltaX = enemyPosition.x - playerPosition.x;
8.             float deltaY = enemyPosition.y - playerPosition.y;
9.             if (Mathf.Abs( deltaX) > Mathf.Abs( deltaY) )
10.                 {
11.                     anim.SetBool("isAttack", true);
12.                     anim.SetFloat("LastHorizontal", deltaX);
13.                    
14.                 }
15.             else if (Mathf.Abs( deltaX) < Mathf.Abs( deltaY))
16.                 {
17.                     anim.SetBool("isAttack", true);
18.                     anim.SetFloat("LastVertical", deltaY);
19.                 }
20.         }