The Crate Populator handles placing crates around the map.

Crate_Populator.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;



public class Crate_Populator : MonoBehaviour
{
    //This list holds the crate prefabs we can spawn.
    public List<GameObject> CrateSpawnables = new List<GameObject>();
    //This variables tells the script how many crates to spawn in the game world
    public int CratesToSpawn;
    //Scale controls how the corresponding pixels in the image are then made into coordinates in the gamewor;d
    public float Scale;
    //This is the noise map the script uses to check whether the crate can be spawned in a certain position
    public Texture2D SpawnMap;

    //This is the list of crates we've already spawned
    public List<GameObject> SpawnedGameObjects = new List<GameObject>();
    
    //We create a list that gives us the random positions to spawn crates at 
    public List<Vector3> SpawnVectors()
    {
        List<Vector3> returnList = new List<Vector3>();
        //we make a loop that iterates as many times we need crates
        for (int i = 0; i < CratesToSpawn;)
        {
            //we generate two random numbers which is a random pixel on the noise map imae
            int x = Random.Range(0, SpawnMap.width);
            int y = Random.Range(0, SpawnMap.height);
            //We check if that pixel is white using GetPixel()
            if(SpawnMap.GetPixel(x,y).grayscale < 0.1f)
            {
                //If it is, we add to our list of positions a Vector3 with our x and y being scaled, and setting the x and z components
                returnList.Add(new Vector3(x/Scale, 0, y/Scale));
                //We then add 1 to i to keep the loop going
                i++;
            }
        }
        return (returnList);
    }
    
    public void Crate_Populate()
    {
        //We make a list of Vector3s with holds the random positions
        List<Vector3> CrateSpawnVectors = SpawnVectors();
        //We go through the list, doing the same thing as before of spawning the objects and adding them to a list.
        foreach (Vector3 x in CrateSpawnVectors)
        {
            GameObject z = Instantiate(CrateSpawnables[Random.Range(0, CrateSpawnables.Count)], x, Quaternion.Euler(0, Random.Range(0, 360), 0)) as GameObject;
            SpawnedGameObjects.Add(z);
        }
    }

    

    public void DestroyAllObjects(){
        foreach (GameObject x in SpawnedGameObjects){
            DestroyImmediate(x);
        }
    }
}