DOTS/ECS spawn random prefab from array

Hello!
I'm trying to spawn random prefabs onto my map every X seconds using ECS, but components are only able to hold basic types and not arrays.

How do I access an array of prefabs in my spawner system and instantiate them?
If I could attach the script to an empty gameobject and drag-n-drop my prefabs onto a public array that would be ideal!

Anyone knows how to do?

 

This belongs in the DOTS forum.

How I'm doing it:

The following is my control script.

Code (CSharp):

1.  
2.     void Start()
3.     {
4.         em = World.DefaultGameObjectInjectionWorld.EntityManager;
5.         var settings = GameObjectConversionSettings.FromWorld(World.DefaultGameObjectInjectionWorld, blobAssetStore);
6.         settings.ConversionFlags = GameObjectConversionUtility.ConversionFlags.AssignName;
7.         weaponEntity = GameObjectConversionUtility.ConvertGameObjectHierarchy(weaponMainLowPrefab, settings);
8.         enemyEntity = GameObjectConversionUtility.ConvertGameObjectHierarchy(enemyPrefab, settings);
9.     }
10.  
11.     Entity CreateEnemy(int state, int X, int Y)
12.     {
13.         var instance2 = em.Instantiate(enemyEntity);
14.         var actionThreshold = 1f;
15.         var health = 100f;
16.         switch (state)
17.         {
18.             case 0:
19.                 actionThreshold = 0.1f;
20.                 health = 100f;
21.                 break;
22.         }
23.         switch(mapStart)
24.         {
25.             case Starts.RegularGrowth:
26.                 health = 10f;
27.                 break;
28.         }
29.         var position = positionMapping[X, Y];
30.  
31.         var we = new EnemyEntity()
32.         {
33.             actionThreshold = actionThreshold,
34.             actionValue = 0,
35.             health = health,
36.             lerp = 0f,
37.             mapCorner0 = mapCorners[0],
38.             mapCorner1 = mapCorners[2],
39.             newPosition = position,
40.             oldPosition = position,
41.             state = state,
42.             weaponEntity = weaponEntity,
43.             X = X,
44.             Y = Y
45.         };
46.         em.SetComponentData(instance2, new Translation { Value = position });
47.         em.SetComponentData(instance2, new Rotation { Value = quaternion.identity });
48.         em.SetComponentData(instance2, we);
49.         return instance2;
50.     }
51.  

The prefabs must already have the components, with the [GenerateAuthoringComponent] tag above the struct, and a ConvertToEntity component (with ConvertAndDestroy selected).

The following is the enemy system.

Code (CSharp):

1.  
2. var weaponCreation = new NativeQueue<WeaponCreationStruct>(Allocator.TempJob);
3.         var parallel = weaponCreation.AsParallelWriter();
4. Entities
5.                 .WithName("EnemySystem")
6.             .WithBurst(Unity.Burst.FloatMode.Default, Unity.Burst.FloatPrecision.Standard, true)
7.             .ForEach((Entity entity, int nativeThreadIndex, ref Translation translation, ref Rotation rotation, ref EnemyEntity enemy, in LocalToWorld localToWorld) =>
8.             {
9.                         parallel.Enqueue(new WeaponCreationStruct()
10.                         {
11.                             velocity = localToWorld.Forward * 55 /** velocity*/,
12.                             entity = enemy.weaponEntity,
13.                             weaponEntity = new WeaponEntity(WeaponType.MainLow, enemy.mapCorner0.x, enemy.mapCorner1.x, enemy.mapCorner0.y, enemy.mapCorner1.y),
14.                             position = front, // any lower and it collides with the player when the player moves
15.                             rotation = frontDir,
16.                         });
17.             }).ScheduleParallel()
18.         Dependency.Complete();
19.         if (weaponCreation.Count > 0)
20.         {
21.             int count = weaponCreation.Count;
22.             for (int i = 0; i < count; i++)
23.             {
24.                 var current = weaponCreation.Dequeue();
25.                 var instance = EntityManager.Instantiate(current.entity);
26.                 EntityManager.SetComponentData(instance, new Translation { Value = current.position });
27.                 EntityManager.SetComponentData(instance, new Rotation { Value = current.rotation });
28.                 EntityManager.SetComponentData(instance, new Unity.Physics.PhysicsVelocity() { Linear = current.velocity });
29.                 EntityManager.SetComponentData(instance, current.weaponEntity);
30.             }
31.         }