Objects pool system

Unity Engine
1

Hey, does anyone knows any good articles/examples/tutorials about making a good objects pool system ?

2

Mike done a live session back in April relating to object pooling, might be worth a watch
http://unity3d.com/learn/tutorials/modules/beginner/live-training-archive/object-pooling

3

Here’s a simple generic pool class I use all over the place. It works with any object that has a publicly accesible constructor that doesn’t take parameters.

    using System.Collections.Generic;
 
    public class Pool<T> where T : new()
    {
        private List<T> pool;
        public int Count
        {
            get
            {
                return pool.Count;
            }
        }
     
        public Pool()
        {
            pool = new List<T>();
        }
             
        public T Get()
        {
            T item;
            if (pool.Count > 0)
            {
                item = pool[0];
                pool.RemoveAt(0);
            }
            else
            {
                item = new T();
            }
            return item;
        }
     
        public void Return(T itemToReturn)
        {
            pool.Add(itemToReturn);
        }
    }

For prefabs, I have a whole seperate pool class, since gameobjects have a few differences:

    using System.Collections.Generic;
 
    public class PrefabPool
    {
        private List<GameObject> pool;
        private GameObject prefab;
        private GameObject poolContainer;
     
        public int Count
        {
            get
            {
                return pool.Count;
            }
        }
     
        public PrefabPool(GameObject prefab)
        {
            if (prefab == null)
                Debug.LogError("Attempt to create PrefabPool with null prefab.");
            this.prefab = prefab;
        }
     
        // Must be initialized in the main game thread, since we're using GameObject.Find and GameObject.Instantiate.
        public void Initialize()
        {
            pool = new List<GameObject>();
            poolContainer = GameObject.Find("PrefabPool Container");
            if (poolContainer == null)
            {
                poolContainer = GameObject.Instantiate(new GameObject);
                poolContainer.name = "PrefabPool Container";
                poolContainer.SetActive(false);
            }
        }
             
        public GameObject Get()
        {
            if (pool == null)
                Initialize();
            GameObject item;
            if (pool.Count > 0)
            {
                item = pool[0];
                pool.RemoveAt(0);
            }
            else
            {
                item = GameObject.Instantiate(prefab);
            }
            return item;
        }
     
        public void Return(GameObject itemToReturn)
        {
            if (pool == null)
                Initialize();
            itemToReturn.transform.SetParent(poolContainer);
            itemToReturn.SetActive(false);
            pool.Add(itemToReturn);
        }
    }

Those should show you the basic principles of pooling. It’s really not too complicated.

4

This is a pretty decent example: http://blogs.msdn.com/b/dave_crooks_dev_blog/archive/2014/07/21/object-pooling-for-unity3d.aspx