Destroy entity in one system and get error in other.

Unity Engine
,
1

Hello, I destroy target entity in this system (bullet hit bot and both should be destroyed)

using Unity.Entities;
using Unity.Mathematics;
using Unity.Transforms;

public class DestructionSystem : ComponentSystem
{
    private EntityManager entityManager;

    protected override void OnStartRunning()
    {
        entityManager = World.DefaultGameObjectInjectionWorld.EntityManager;
    }

    protected override void OnUpdate()
    {
        Entities.WithAll<Destructor>().ForEach((Entity vilian, ref Translation vilianTrans, ref Destructor destructor) =>
        {
            float3 vilianPos = vilianTrans.Value;

            Entities.WithAll<Destructable>().ForEach((Entity victim, ref Translation victimTrans, ref Destructable destructable) =>
            {
                if (math.distance(vilianPos, victimTrans.Value) < 1)
                {
                    entityManager.DestroyEntity(vilian);
                    entityManager.DestroyEntity(victim);
                }
            });
        });
    }
}

But in the other system I have code like this

public class AttackSystem : ComponentSystem
{
    protected override void OnUpdate()
    {
        Entities.WithAll<BehaviourStateAttacking>().ForEach((
            Entity entity,
            ref Translation translation,
            ref Rotation rotation,
            ref BehaviourStateAttacking behaviourStateAttacking,
            ref Turning turning,
            ref ShootTimer shootTimer
            ) =>
        {
            float3 myPos = translation.Value;
            quaternion myRot = rotation.Value;
            float turningSpeed = turning.TurningSpeed;
           
            float3 turgetPoint = World.DefaultGameObjectInjectionWorld.EntityManager.GetComponentData<Translation>(behaviourStateAttacking.AttackTarget).Value;

In the last published line I have an error that sais “ArgumentException: A component with type:Translation has not been added to the entity.”
how to fix the issue?

2

The entity you destroyed is going to be the same as your attack target, behaviourStateAttacking.AttackTarget

An entity that doesn’t exist doesn’t have a translation value.

3

Thank you, capitan. But how do I fix the error, when I destroy entity in one system and try to get entity in the other? What kind of if_entity_exist do I have to use?

4

Most of the time you’re using entity references you need to check it has the component first (HasComponent) and handle that.

5

Thank you.

if (EntityManager.HasComponent(behaviourStateAttacking.AttackTarget, typeof(Translation)))