Wave Spawner | Instaniating Enemys will Overlap

Question

I am creating a wave Spawner with SpawnPositions but sometimes the Enemies will Overlap...

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class SpawnController : MonoBehaviour {
 
     public Transform[] spawnPos;
     public GameObject enemyPrefab;
     public float timeBetweenWaves = 1f;
     public float timeToSpawn;
     public int enemysEachWave;
     GameObject clone;
 
     void Start () {
         Spawn();
     }
     
 
     void Update () {
         if(Time.time >= timeToSpawn)
         {
             Spawn();
             timeToSpawn = Time.time + timeBetweenWaves;
         }
     }
 
     void Spawn()
     {
         for (int i = 0; i < enemysEachWave; i++)
         {
             clone = Instantiate(enemyPrefab, spawnPos[Random.Range(0, spawnPos.Length)].position, Quaternion.identity);
         }
     }
 }

Answer 1

Best Answer

Answer by Harinezumi · Feb 13, 2018 at 01:04 PM

To avoid spawning enemies at the same position within a wave you need 1) at least as many spawn positions as enemies 2) only use each spawning positions once.
The first needs to be set up by you.
For the second, either shuffle the array of spawning positions, or you create a list of the positions and remove a position every time it is used (no worries, the original array remains. See below the second approach:

 using System.Collections.Generic; // add this to the top
 
 void Spawn () {
      List<Transform> unusedSpawnPositions = new List<Transform>();
      unusedSpawnPositions.AddRange(spawnPos); // add the positions defined to the list
      for (int i = 0; i < enemysEachWave; ++i) {
           if (unusedSpawnPositions.Count < 1) { break; } // protect against empty list
           int spawnPosIndex = Random.Range(0, unusedSpawnPositions.Count); // select index of spawn position
           clone = Instantiate(enemyPrefab, unusedSpawnPositions[spawnPosIndex];
           unusedSpawnPositions.RemoveAt(spawnPosIndex); // remove spawn position
      }
 }

Add comment · Show 1 · Share

Floreo · Feb 13, 2018 at 01:09 PM 0

Share

Thanks, it worked perfectly :)

Answer 2

Answer by yummy81 · Feb 13, 2018 at 12:56 PM

It seems to me that you did not add any script to your enemyPrefab which would put the instance of this prefab into motion. It can be also that the script does exist but is not enabled. Or some public variables (like speed) are not assigned in the inspector. It's hard to say, but try to attach this simple script to your enemyPrefab. If clones start moving that means you have the solution:

 using UnityEngine;
 
 public class Enemy : MonoBehaviour
 {
     public float speed = 3f;
         
     private void Update()
     {
         transform.position += Time.deltaTime * speed * transform.forward;
     }
 }

Add comment · Show 1 · Share

Floreo · Feb 13, 2018 at 01:02 PM 1

Share

Thanks but my Problem I need a solution for is the Spawning because sometimes 2 Enemies spawn on the same Spawnpoint so they overlap. Sorry, my Question wasn't clear enough :/

Answer 3

Answer by melsy · Feb 13, 2018 at 01:11 PM

So i have thought abou this issue with a project i was working on awhile back and what i was thinking about doing was this. Create a dummy game object in the scene with a collider the same size as the enemy. Reference the empty game object on the wave spawner.
When the wave spawner wants to spawn an enemy , have it move the dummy object to the point and if it hits collision randomize the location again. Then set the dummy to Setactive(false) and do the process again .

 pseudo code 

   dummyObject = DO
   wave spawner wants to spawn. 
   DO is moved into that position
   DO is setactive(true)
   if DO has collision
        wave spawner gets a new position 
        DO is moved to that new position
   if no collision
        spawn the enemy.

Add comment · Show 2 · Share

Harinezumi · Feb 13, 2018 at 01:29 PM 0

Share

Interesting approach, but you can't detect collision in the same frame that you are currently, only in the next physics update. A raycast or even capsulecast would be better then, but possibly more expensive.

melsy Harinezumi · Feb 13, 2018 at 01:38 PM 0

Share

for what i was doing with simple enemies spawning randomly then walking around a frame didn't matter. I never tried to make it work i just thought about it over time.

Wave Spawner | Instaniating Enemys will Overlap

3 Replies

Your answer

Welcome to Unity Answers

Follow this Question

Related Questions