対象の方を向く

FollowTargetSystem.cs

using Unity.Entities;
using Unity.Jobs;
using Unity.Collections;
using Unity.Burst;
using Unity.Transforms;
using Unity.Mathematics;

public class FollowTargetSystem : JobComponentSystem
{
    protected override JobHandle OnUpdate(JobHandle inputDeps)
    {
        inputDeps = new LookTargetJob {
            positionFromEntity = GetComponentDataFromEntity<Position>(true)
        }.Schedule(this, inputDeps);

        return inputDeps;
    }
    
    [BurstCompile]
    private struct LookTargetJob : IJobProcessComponentData<Target, Position, Rotation>
    {
        [ReadOnly] public ComponentDataFromEntity<Position> positionFromEntity;

        public void Execute([ReadOnly] ref Target target, [ReadOnly] ref Position pos, [WriteOnly] ref Rotation rot)
        {
            if (!positionFromEntity.Exists(target.Value))
                return;
             
            var targetPos = positionFromEntity[target.Value];
            var diff = targetPos.Value - pos.Value;
            rot.Value = quaternion.LookRotationSafe(diff, new float3(0, 1, 0));
        }
    }
}

TargetComponent.cs

using UnityEngine;
using Unity.Entities;

[DisallowMultipleComponent]
public class TargetComponent : ComponentDataWrapper<Target>{}

[System.Serializable]
public struct Target : IComponentData
{
    public Entity Value;
}