Zombie Horde Movement

Hello,

I am working on a Top-Down (for now) survival shooter. I am am experienced programmer (fairly new to Unity). I have used Unity's navmesh and understand how it works. I am wondering how I would do horde AI. Not only following the player, but some choosing to attack and attempt to break down windows / doors, and others taking the easiest path through already open doors.

Basically, how do I limit a window to maybe 5 or 6 zombies at a time trying to get through while the rest choose a different entrance? How is something like this usually done in Unity with the navmesh system. I am not asking for someone to code it for me, just the best approach. Thank you

 

Id be curious how others may work on this.

Some ideas- use multiple targets.
have a simple list script for attackable objects.
When an object is attacked by a zombie add that zombie to its list.
only let a zombie attack an object that has an open list of attackers.

Code (CSharp):

1.  
2. using UnityEngine;
3. using System.Collections;
4. using System.Collections.Generic;
5.  
6. public class JBR_AI_Search_System : MonoBehaviour {
7. //add proper tags in inspector
8. public string playerTag;
9. public string npcTag;
10. public string MiscTargetTag;
11.  
12. // allow targeting of each type of target
13. public bool canTargetPlayerTag;
14. public bool canTargetNPCTag;
15. public bool canTargetMiscTargetTag;
16.  
17.  //list of all targets
18.     public List<GameObject> allTargets = new List<GameObject>();
19.     //array of each target type
20.     public GameObject[] playerTargets;
21.     public GameObject[] NPCTargets;
22.     public GameObject[] miscTargets;
23.  
24.  // Use this for initialization
25.     void Start()
26.     {
27. //optimization does this check 10 times per second vs. 30-60 times in regular update
28.  InvokeRepeating("CheckForTargets", 0.1f, 0.1f);
29. }
30. void CheckForTargets(){
31.  //clear list of targets before we redo the list
32.             allTargets.Clear();
33.             //if checked add all player targets
34.             if (canTargetPlayerTag)
35.             {
36.                 playerTargets = GameObject.FindGameObjectsWithTag(playerTag);
37.                 for (int i = 0; i < playerTargets.Length ; i++)
38.                 {
39.                     allTargets.Add(playerTargets[i]);
40.                     Debug.Log(playerTargets[i]);
41.                 }
42.             }
43.             //if checked add all NPC targets
44.             if (canTargetNPCTag)
45.             {
46.                 NPCTargets = GameObject.FindGameObjectsWithTag(npcTag);
47.                 for (int i = 0; i < NPCTargets.Length ; i++)
48.                 {
49.                     allTargets.Add(NPCTargets[i]);
50.                 }
51.             }
52.             //if checked add all Misc targets
53.             if (canTargetMiscTargetTag)
54.             {
55.                 miscTargets = GameObject.FindGameObjectsWithTag(MiscTargetTag);
56.                 for (int i = 0; i < miscTargets.Length ; i++)
57.                 {
58.                     allTargets.Add(miscTargets[i]);
59.                 }
60.             }
61.             //checked through list of all targets
62.             if (allTargets.Count > 0)
63.             {
64.                 for (int i = 0; i < allTargets.Count ; i++)
65.                 {
66.              
67.                     //sift through all the targets for the best one
68.                     // checks the distance away from ai to target
69.                     float cDistance = Vector3.Distance(this.transform.position, allTargets[i].transform.position);
70. Debug.Log("All Targets - " + allTargets[i] + "distance " + cDistance);
71. }
72.  

 

Attackers handling

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3. using System.Collections.Generic;
4.  
5. // basic Aggro handling of anything that can be attacked
6. public class JBR_AttackableObject : MonoBehaviour {
7.  
8.     public int maxAttackers = 6;        //max allowed attackers
9.     public GameObject[] Attackers ;     //Array of attackers
10.     public bool LimitReached = false;   //if array is full sets to true
11.  
12.  
13. // Use this for initialization
14.     void Start () {
15.         Attackers = new GameObject[maxAttackers];
16.         Debug.Log(Attackers.Length);
17.     }
18.  
19.     // Update is called once per frame
20.     void Update () {
21.  
22.     }
23.     //method for adding Attackers
24.     public void TakeDamage(GameObject attackerGO)
25.     {
26.         //look through all array slots
27.         for (int i = 0; i < Attackers.Length +1; i++)
28.         {
29.             // first we check that this attacker hasnt been added to the array already
30.             if(Attackers[i] == attackerGO)
31.             {
32.                 Debug.Log("Duplicate Attacker " + this.gameObject.name);
33.                 return;
34.             }
35.             //next we add the attacker to the first open slot in the array
36.             if(Attackers[i] == null )
37.             {
38.              
39.                 Attackers[i] = attackerGO;
40.                 Debug.Log("New Attacker added " + this.gameObject.name);
41.                 return;
42.             }
43.             //if we made it to maxAttackers limit then set as limit reached
44.             if(i >= maxAttackers)
45.             {
46.                 LimitReached = true;
47.                 Debug.Log("Limit Reached " + this.gameObject.name);
48.                 return;
49.             }
50.         }
51.     }
52.     //method for removing Attackers
53.     public void RemoveAttacker(GameObject removedAttacker)
54.     {
55.         //look through all array slots
56.         for (int i = 0; i < Attackers.Length; i++)
57.         {
58.             if (Attackers[i] == removedAttacker)
59.             {
60.                 LimitReached = false;
61.                 Attackers[i] = null;
62.                 Debug.Log("Removed Attacker " + this.gameObject.name);
63.                 return;
64.             }
65.         }
66.     }
67. }