Object pool for multiple types of projectile

Questions & Answers
1

I’m wondering, how do people normally make a pool for object that has multiple types? in my case i wanted to do an object pool that could support multiple types of projectile. the projectile will behave in different ways and also have different mesh.

what i had in mind is have the projectile derive the off a base and pool that instead, then when i grab a projectile from the pool i’ll reassign mesh and instantiate it as the type of projectile i want.

GenericProjectile tempProjectile = ProjectilePool.instance.GetProjectile();

tempProjectile = new CannonShell();

i think this is the way to go but i feel like i’m missing something. any guidance will be much appreciated.

2

I was in ur situation a few weeks ago, i wrote a pool script for multiple objects in a pool with diffrent amounts of each.
It also has a fallback where if you create more object then you first created it will create a new one of that object and add it to the pool.

using UnityEngine;
using System.Collections.Generic;

[System.Serializable]
public class PooledObject
{
    public GameObject Object;
    public int Amount;
}

public class Pool : MonoBehaviour
{
    public static Pool Instance;
    public PooledObject[] Objects;
    private List<GameObject>[] pool;

    void Awake()
    {
        Instance = this;
    }
	void Start()
    {
        GameObject temp;
        pool = new List<GameObject>[Objects.Length];

        for (int count = 0; count < Objects.Length; count++)
        {
            pool[count] = new List<GameObject>();
            for (int num = 0; num < Objects[count].Amount; num++)
            {
                temp = (GameObject)Instantiate(Objects[count].Object, new Vector3(0.0f, 1000.0f, 0.0f), Quaternion.identity);
                temp.SetActive(false);
                temp.transform.parent = transform;
                pool[count].Add(temp);
            }
        }
	}
    public GameObject Activate(int id, Vector3 position, Quaternion rotation)
    {
        for (int count = 0; count < pool[id].Count; count++)
        {
            if (!pool[id][count].activeSelf)
            {
                GameObject currObj = pool[id][count];
                Transform currTrans = currObj.transform;

                currObj.SetActive(true);
                currTrans.position = position;
                currTrans.rotation = rotation;
                return currObj;
            }
        }
        GameObject newObj = Instantiate(Objects[id].Object) as GameObject;
        Transform newTrans = newObj.transform;
        newTrans.position = position;
        newTrans.rotation = rotation;
        newTrans.parent = transform;
        pool[id].Add(newObj);
        return newObj;
    }
    
    public void Deactivate(GameObject obj)
    {
        obj.SetActive(false);
    }
}

Then in another script if you need an object do this:

// Your object id
int id = 0;

// Your position
Vector3 position = Vector3.zero;

// Your rotation
Quaternion rotation = Quaternion.Eular(new Vector(0,0,0));

Pool.Instance.Activate(id, position, rotation);

And if your done with one using a timed check or whatever use:

Pool.Instance.Deactivate(gameObject);