Entityの生成と保存

CreateEntities.cs

using Unity.Entities;
using Unity.Transforms;
using UnityEngine;
using Unity.Collections;

public class CreateEntities : MonoBehaviour
{
    [SerializeField] GameObject[] spawnObjects;

    public void Spawn()
    {
        var random = new Unity.Mathematics.Random((uint)Time.frameCount);
        var entityManager = World.Active.GetExistingManager<EntityManager>();

        foreach( var obj in spawnObjects)
        {
            var count = random.NextInt(100, 1000);
            var entities = new NativeArray<Entity>(count, Allocator.Temp);
            entityManager.Instantiate(obj, entities);
            for (int i=0; i<count; i++)
            {
                var newPos = new Position() { Value = random.NextFloat3(-1, 1) * 10 };
                entityManager.SetComponentData(entities[i], newPos);
            }
            entities.Dispose();
        }
    }
}

SaveWorld.cs

using Unity.Entities;
using Unity.Entities.Serialization;
using UnityEngine;

public class SaveWorld : MonoBehaviour
{
    [SerializeField] string fileName = "save.sav";

    public void Save()
    {
        var entityManager = World.Active.GetExistingManager<EntityManager>();
        using (var writer = new StreamBinaryWriter(fileName))
        {
            SerializeUtilityHybrid.Serialize(entityManager, writer, out GameObject sharedDataResult);
        }
    }
}