How to spawn randomly positioned objects without overlapping

Question

Hi, I can spawn objects randomly but sometimes they overlapping. I want to spawn objects without overlapping how can I do it? My spawn code:

 public void StartGame() {
         count = Random.Range(2, 6);
 
         for(int i = 0; i < count; i++) {
             float x = Random.Range(-2.0f, 2.0f);
             float y = Random.Range(-4.0f, 4.0f);
 
             Instantiate(enemy, new Vector3(x, y, 0), Quaternion.identity);
         }
     }

Answer 1

Best Answer

Answer by MaxLevelNoob · Apr 22, 2020 at 01:43 PM

 public void StartGame()
 {
     count = Random.Range(2, 6);
     float enemyRadius = enemy.GetComponent<Collider2D>().bounds.extents.x;

     for (int i = 0; i < count; i++)
     {
         float x = Random.Range(-2.0f, 2.0f);
         float y = Random.Range(-4.0f, 4.0f);
         Vector2 spawnPoint = new Vector2(x, y);

         //Assuming you are 2D
         Collider2D CollisionWithEnemy = Physics2D.OverlapCircle(spawnPoint, enemyRadius, LayerMask.GetMask("EnemyLayer"));

         //If the Collision is empty then, we can instantiate
         if (CollisionWithEnemy == false)
             Instantiate(enemy, new Vector3(x, y, 0), Quaternion.identity);
     }
 }

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MaxLevelNoob · Apr 22, 2020 at 01:52 PM 0

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Basically using Physics2D to check for any collisions around your spawnPoint, and if there isn't, we'll instantiate, otherwise we won't.

Answer 2

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Test : MonoBehaviour
 {
     public GameObject enemy;
     public float distanceBetweenObjects = 2f;
     List<Vector3> points = new List<Vector3>();
     
     void Start(){
         ObjectPositioning();
         ObjectSpawning();
     }
     
     void ObjectPositioning(){
         int count = Random.Range(2, 6);
 
         for(int i = 0; i < count;) {
             float x = Random.Range(-2.0f, 2.0f);
             float y = Random.Range(-4.0f, 4.0f);
             Vector3 point = new Vector3(x, y, 0);
             
             if (points.Count==0){
                 points.Add(point);
                 i++;
                 continue;
             }
             
             for(int j = 0; j < points.Count; j++){
                 
                 if ((point-points[j]).sqrMagnitude > distanceBetweenObjects * distanceBetweenObjects){
                     if (j==points.Count-1){
                         points.Add(point);
                         i++;
                     }
                     continue;
                 }            
                 break;
             }    
         }
     }
 
     void ObjectSpawning(){
         for (int i = 0; i < points.Count; i++){
             Instantiate(enemy, points[i], Quaternion.identity);
         }
     }
 }

How to spawn randomly positioned objects without overlapping

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