A ScriptableObject is a data container that you can use to save large amounts of data, independent of class instances. One of the main use cases for ScriptableObjects is to reduce your Project’s memory usage by avoiding copies of values. This is useful if your Project has a Prefab that stores unchanging data in attached MonoBehaviour scripts.
Every time you instantiate that Prefab, it will get its own copy of that data. Instead of using the method, and storing duplicated data, you can use a ScriptableObject to store the data and then access it by reference from all of the Prefabs. This means that there is one copy of the data in memory.
Just like MonoBehaviours, ScriptableObjects derive from the base Unity object but, unlike MonoBehaviours, you can not attach a ScriptableObject to a GameObject. Instead, you need to save them as Assets in your Project.
When you use the Editor, you can save data to ScriptableObjects while editing and at run time because ScriptableObjects use the Editor namespace and Editor scripting. In a deployed build, however, you can’t use ScriptableObjects to save data, but you can use the saved data from the ScriptableObject Assets that you set up during development.
Data that you save from Editor Tools to ScriptableObjects as an asset is written to disk and is therefore persistent between sessions.
ScriptableObject の主な使用例は以下のとおりです。
To use a ScriptableObject, create a script in your application’s Assets folder and make it inherit from the ScriptableObject class. You can use the CreateAssetMenu attribute to make it easy to create custom assets using your class. For example:
using UnityEngine;
[CreateAssetMenu(fileName = "Data", menuName = "ScriptableObjects/SpawnManagerScriptableObject", order = 1)]
public class SpawnManagerScriptableObject : ScriptableObject
{
public string prefabName;
public int numberOfPrefabsToCreate;
public Vector3[] spawnPoints;
}
Assets フォルダー内に作成した上のスクリプトを使用して、Assets > Create > ScriptableObjects > SpawnManagerScriptableObject の順に選択し、ScriptableObject のインスタンスを作成できます。新しい ScriptableObject インスタンスに分かりやすい名前をつけ、値を変更します。これらの値を使用するには、ScriptableObject を参照する新しいスクリプト (この場合は SpawnManagerScriptableObject) を作成する必要があります。以下はその例です。
using UnityEngine;
public class Spawner : MonoBehaviour
{
// インスタンス化するゲームオブジェクト
public GameObject entityToSpawn;
// 上で定義した ScriptableObject のインスタンス
public SpawnManagerScriptableObject spawnManagerValues;
// 作成されたエンティティの名に追加され、それぞれが作成されるたびにインクリメントされます。
int instanceNumber = 1;
void Start()
{
SpawnEntities();
}
void SpawnEntities()
{
int currentSpawnPointIndex = 0;
for (int i = 0; i < spawnManagerValues.numberOfPrefabsToCreate; i++)
{
// 現時点のスポーン位置でプレハブのインスタンスを作成します。
GameObject currentEntity = Instantiate(entityToSpawn, spawnManagerValues.spawnPoints[currentSpawnPointIndex], Quaternion.identity);
// インスタンス化したエンティティの名前が ScriptableObject で定義した文字列になるように設定し、次に、固有の番号を追加します。
currentEntity.name = spawnManagerValues.prefabName + instanceNumber;
// スポーン位置の次のインデックスに移動します。インデックスを超えた場合は、最初に戻ります。
currentSpawnPointIndex = (currentSpawnPointIndex + 1) % spawnManagerValues.spawnPoints.Length;
instanceNumber++;
}
}
}
Attach the above script to a GameObject in your Scene. Then, in the Inspector, set the Spawn Manager Values field to the new SpawnManagerScriptableObject that you set up.
Set the Entity To Spawn field to any Prefab in your Assets folder, then click Play in the Editor. The Prefab you referenced in the Spawner instantiates using the values you set in the SpawnManagerScriptableObject instance.
If you’re working with ScriptableObject references in the Inspector, you can double click the reference field to open the Inspector for your ScriptableObject. You can also create a custom Editor to define the look of the Inspector for your type to help manage the data that it represents.