MonoBehaviourとComponentDataの同期

DisplayPlayerDistance.cs

using Unity.Entities;
using UnityEngine;

public class DisplayPlayerDistance : MonoBehaviour
{

    DistanceFromPlayerAuthoring fromPlayer;

    void Start()
    {
        fromPlayer = GetComponent<DistanceFromPlayerAuthoring>();
    }

    // Update is called once per frame
    void Update()
    {
        Debug.Log(fromPlayer.Distance);
    }
}

DistanceFromPlayerAuthoring.cs

using Unity.Entities;
using Unity.Jobs;
using Unity.Mathematics;
using Unity.Transforms;
using UnityEngine;
using static Unity.Entities.ComponentType;

[DisallowMultipleComponent]
[RequiresEntityConversion]
public class DistanceFromPlayerAuthoring : MonoBehaviour, IConvertGameObjectToEntity
{
    /// <summary> プレイヤーとの距離 </summary>
    public float Distance { get; set; }

    public void Convert(Entity entity, EntityManager dstManager, GameObjectConversionSystem conversionSystem)
    {
        dstManager.AddComponentData(entity, new DistanceFromPlayer());
    }
}

// DistanceFromPlayerをDistanceFromPlayerAuthoringに反映するシステム
[UpdateInGroup(typeof(InitializationSystemGroup))]
public class SetDistanceDataToAnimator : ComponentSystem
{
    protected override void OnUpdate()
    {
        Entities.ForEach((DistanceFromPlayerAuthoring authoring, ref DistanceFromPlayer distance) => authoring.Distance = distance.Value);
    }
}


/// <summary> PlayerTagを持つEntityとの距離 </summary>
[System.Serializable]
public struct DistanceFromPlayer : IComponentData
{
    public float Value;
}

/// <summary>
///　PlayerTagとDistanceFromPlayerの距離をValueに格納するシステム
/// </summary>
public class DistanceCheckSystem : JobComponentSystem
{
    EntityQuery playerQuery;
    protected override void OnCreate()
    {
        playerQuery = GetEntityQuery(ReadOnly<PlayerTag>(), ReadOnly<LocalToWorld>());
        RequireForUpdate(playerQuery);
    }

    protected override JobHandle OnUpdate(JobHandle inputDeps)
    {
        var playerPos = playerQuery.GetSingleton<LocalToWorld>().Position;
        inputDeps = Entities
            .ForEach((ref DistanceFromPlayer distance, in LocalToWorld pos) =>
            {
                distance.Value = math.distance(pos.Position, playerPos);
            }).Schedule(inputDeps);
        return inputDeps;
    }
}