Scriptable Objects

Written by: Akram Taghavi-Burris | © Copyright 2024

Scriptable Objects allow you to create reusable data containers that exist outside of the typical MonoBehaviour script. They provide an efficient way to store and manage data that can be shared across multiple instances without requiring duplication, making them a powerful tool for optimizing and organizing game data.

Copy vs. Clone

When creating instances of prefabs, each instance is a copy that inherits the properties of the original, but with its own separate memory allocation. Even if properties are shared across instances, each one manages its own memory, leading to inefficiencies when many instances exist. This applies even to static properties that remain consistent across instances, each still holds its own memory space.

Scriptable Objects behave more like clones rather than copies. Instead of duplicating data in memory for each instance, Scriptable Objects share a single memory allocation. All objects referencing a Scriptable Object access the same centralized data. This makes Scriptable Objects ideal for situations where multiple objects share the same properties, such as in a game with hundreds of instances of items like wood, stone, or metal.

By using Scriptable Objects, all instances of these items point to the same memory location for shared properties like name, value, and rarity. This significantly reduces memory usage and improves performance, making Scriptable Objects an efficient solution for managing shared data across many instances.

Declaring a Scriptable Object

To declare a Scriptable Object, it inherits from ScriptableObject rather than MonoBehaviour. Scriptable Objects do not need to be attached to game objects , allowing them to act as standalone data containers. Here's an example of how to declare a Scriptable Object in code:

using UnityEngine;

[CreateAssetMenu(fileName = "New Collectable", menuName = "Collectable Data")]
public class CollectableData : ScriptableObject
{
    public string itemName;
    public int value;
    public Sprite icon;
}

This code snippet includes the CreateAssetMenu attribute, making it easy to create instances of the CollectableData Scriptable Object from Unity's asset creation menu.

Scriptable Object "Data" Class

Notice the use of the suffix "Data" in the class name. This is a common convention when naming Scriptable Objects, as it indicates that the object is primarily used for storing and managing data. Using this suffix helps distinguish Scriptable Objects from other classes, such as those inheriting from MonoBehaviour, which typically contain behavior logic tied to GameObjects.

When to Implement

Scriptable Objects are best used when you need to store and manage data independently of scene instances. This can include:

• Centralizing Data: Scriptable Objects allow you to define data once and use it across multiple scenes or game objects without needing to reinstantiate it, ensuring consistency and reducing redundancy.

• Optimizing Performance: By storing data in Scriptable Objects, you reduce the need for duplicating data in multiple game objects, lowering memory usage and improving game performance.

• Modular Design: Scriptable Objects promote modularity by keeping data separate from behavior. This makes it easier to swap or update data without having to modify the behavior of objects that depend on it.

• Shared Configurations: Use Scriptable Objects for global configurations or settings that need to be accessed by multiple objects, such as player stats, inventory items, or enemy attributes.