Question Issue spawning entities

Hey guys. I am trying to spawn a lot of entities and move them down by deltaTime. There are entites in the entity hierarchy, but the only entity being rendered is the one that's already present in the scene hierarchy on startup.
This is my SpawningSystem:

Code (CSharp):

1. using Unity.Entities;
2. using Unity.Mathematics;
3. using Unity.Transforms;
4.  
5. public partial class AgentSpawningSystem : SystemBase
6. {
7.     protected override void OnStartRunning()
8.     {
9.  
10.         AgentSpawnSettings settings = SystemAPI.GetSingleton<AgentSpawnSettings>();
11.         Entity agent = EntityManager.GetComponentData<MovementAgent>(SystemAPI.GetSingletonEntity<MovementAgent>()).Prefab;
12.  
13.         Random rnd = new Random();
14.         rnd.InitState(49600);
15.  
16.         for (int i = 0; i < settings.SpawnAmount; i++)
17.         {
18.             float3 rndPos = rnd.NextFloat3(settings.MinPos, settings.MaxPos);
19.  
20.             LocalTransform localTransform = new LocalTransform
21.             {
22.                 Position = rndPos
23.             };
24.             Entity spawnEntity = EntityManager.Instantiate(agent);
25.             EntityManager.SetComponentData(spawnEntity, localTransform);
26.         }
27.     }
28.    
29.     protected override void OnUpdate()
30.     {
31.  
32.     }
33. }
34.  

This script is attached to the agent prefab in the scene hierarchy:

Code (CSharp):

1. using Unity.Entities;
2. using UnityEngine;
3.  
4. public class SpawnedAgent : MonoBehaviour
5. {
6.     public GameObject Prefab;
7. }
8.  
9. public class BakeMovementAgent : Baker<SpawnedAgent>
10. {
11.     public override void Bake(SpawnedAgent authoring)
12.     {
13.         Entity entity = GetEntity(TransformUsageFlags.Dynamic);
14.         Entity prefabEntity = GetEntity(authoring.Prefab, TransformUsageFlags.Renderable);
15.         AddComponent(entity, new MovementAgent
16.         {
17.             Prefab = prefabEntity
18.         });
19.     }
20. }
21.  
22.  

This is my component data:

Code (CSharp):

1. using Unity.Entities;
2. using Unity.Mathematics;
3.  
4. public struct MovementAgent : IComponentData
5. {
6.     public Entity Prefab;
7. }
8.  
9. public struct AgentFlag : IComponentData
10. {
11.  
12. }
13. public struct AgentSpawnSettings : IComponentData
14. {
15.     public int SpawnAmount;
16.     public float3 MinPos;
17.     public float3 MaxPos;
18. }

This is what my scene hierarchy looks like:


This is my entity hierarchy:

(As you can see, the entities are instantiated)

This is what it looks like in the scene:


If I click on any of the entities, this entity is highlighted. But all the entities have different positions. Very weird to me.

Appreciate any help!

 

You did not initialize the LocalTransform correctly. You did not specify a rotation or scale, which means they will default to 0 as will happen when struct members are not initialized in the object initializer (when the default constructor is used). A quarternion of 0’s is invalid, and a scale of 0 is obviously not correct. You need to set the rotation to something valid like quaternion.identity and the scale to a correct value. You can also use some of the static methods to create valid LocalTransform here.
https://docs.unity3d.com/Packages/com.unity.entities@1.0/api/Unity.Transforms.LocalTransform.html

 

I changed the for loop to this:

Code (CSharp):

1.         for (int i = 0; i < settings.SpawnAmount; i++)
2.         {
3.             float3 rndPos = rnd.NextFloat3(settings.MinPos, settings.MaxPos);
4.  
5.             LocalTransform localTransform = LocalTransform.FromPosition(rndPos);
6.  
7.             Entity spawnEntity = EntityManager.Instantiate(agent);
8.             EntityManager.SetComponentData(spawnEntity, localTransform);
9.         }

Still the same result as before.

 

Your agents probably don't have a localTransform component, because you set the transformUsageFlag to renderable (only a localToWorld) on your agent entity prefab

 

Added the component:

Code (CSharp):

1. using Unity.Entities;
2. using Unity.Mathematics;
3. using Unity.Transforms;
4.  
5. public partial class AgentSpawningSystem : SystemBase
6. {
7.     protected override void OnStartRunning()
8.     {
9.  
10.         AgentSpawnSettings settings = SystemAPI.GetSingleton<AgentSpawnSettings>();
11.         Entity agent = EntityManager.GetComponentData<MovementAgent>(SystemAPI.GetSingletonEntity<MovementAgent>()).Prefab;
12.  
13.         Random rnd = new();
14.         rnd.InitState(49600);
15.  
16.         for (int i = 0; i < settings.SpawnAmount; i++)
17.         {
18.             float3 rndPos = rnd.NextFloat3(settings.MinPos, settings.MaxPos);
19.  
20.             LocalTransform localTransform = LocalTransform.FromPosition(rndPos);
21.  
22.             Entity spawnEntity = EntityManager.Instantiate(agent);
23.             EntityManager.AddComponent<LocalTransform>(spawnEntity);
24.             EntityManager.SetComponentData(spawnEntity, localTransform);
25.         }
26.     }
27.    
28.     protected override void OnUpdate()
29.     {
30.  
31.     }
32. }
33.  

Still doesn't work.

 

Hum, it should work in that case. Or at least i don't see the problem. And you are saying that all entities have different position? In that case, i suppose it is a problem with the rendering, check the RenderMeshArray, the RenderMesh and RenderBounds components, see if there is a problem there.

I'll try your code on my machine as soon as i get home.

 

I've tried to reproduce your code, and there is something i don't understand. It works on my side, but all the instantiated entities are not prefabs, just instantiated entities (they don't have the blue icon in entity hierarchy), so definitely not what you get in your image. Are you on the last version of entities?

 

Maybe because you're missing the settings object. I created an empty object in the scene hierarchy, and added this script:

Code (CSharp):

1. using Unity.Entities;
2. using UnityEngine;
3.  
4. public class AgentSettings : MonoBehaviour
5. {
6.     public Vector3 MinPos;
7.     public Vector3 MaxPos;
8.     public int SpawnCount;
9.  
10.     private void OnDrawGizmos()
11.     {
12.         Gizmos.color = Color.yellow;
13.         Gizmos.DrawWireSphere(MinPos, 1f);
14.         Gizmos.DrawWireSphere(MaxPos, 1f);
15.     }
16. }
17.  
18. public class BakeAgentSettings : Baker<AgentSettings>
19. {
20.     public override void Bake(AgentSettings authoring)
21.     {
22.         Entity entity = GetEntity(TransformUsageFlags.Dynamic);
23.         AddComponent(entity, new AgentSpawnSettings
24.         {
25.             SpawnAmount = authoring.SpawnCount,
26.             MinPos = authoring.MinPos,
27.             MaxPos = authoring.MaxPos,
28.         });
29.     }
30. }

Then I selected the "Agent" object from the scene hierarchy as Prefab, see screenshot below:

 

And yes, all entities have different positions, and I am on the latest version of entities.

 

Also, all entities seem to reference the initial "Agent" prefab. Every time I click on one, the initial prefab is highlighted. But they all have different positions in the inspector.

 

No, I did not miss the settings object. My cubes spawned with your scripts, thus my wonder. Do you reference the agent gameobject in your subscene or the actual prefab in asset folder?

 

My results (I'm in 3D). The only thing I changed from your scripts is that I added an OnCreate in the system, to RequireForUpdate the singletons, otherwise I was just getting "singleton query must be one but found 0" type errors. All the rest is from you. Does the agent have anything else as component other than the render components?

 

I reference the agent gameobject in the subscene.

 

This:

Is the output of this: (Which I added to the SpawningSystem)

Code (CSharp):

1.         int counter = 0;
2.         foreach ((LocalTransform tranform,Entity entity) in SystemAPI.Query<LocalTransform>().WithEntityAccess())
3.         {
4.             NativeArray<ComponentType> arr = EntityManager.GetComponentTypes(entity);
5.             foreach (var item in arr)
6.             {
7.                 Debug.Log(item);
8.             }
9.             if(counter >= 5) break;
10.             counter++;
11.         }

 

I removed the prefab the object in the scene referenced and just added the agent to the scene without prefab. They spawn now. What the heck?

 

Ah, you have a companion link! I've not done any 2d or ui, so i did not know that unity puts a companion link on every sprite renderer converted entities. So i've tested with a sprite renderer instead of mesh filter+mesh renderer, and what i get is still different of your image. In the setup of agent prefab gameobject put directly in subscene, and reference as gameobject in subscene and not external prefab (what you had in the beginning), i just get that the entities spawn at random position, but for some reason, the companion gameobject is not in the hierarchy or rendering (but it exists, as the companion link field shows), they are not blue prefabs icons though, so it is not exactly like you. And whatever the way I try (referencing the agent as non prefab, or referencing directly the prefab), the sprites don't render. I'm curious now. What exactly have you done do unlock the rendering? What are you referencing in the agent prefab field in the SpawnedAgent authoring?

 

They were grey icons after I got it running:

I simply deleted the prefab in the assets (So it doesn't exist in the file explorer) and added the agent to the scene without being a prefab:

This agent is what I am referencing as prefab.

But there's another issue I am running into now When trying to move them in the Entities.ForEach loop, using .Run(), .Schedule(). and ScheduleParallel() all have the same performance
Do you know what could cause that? If so, code below, if not, I still have to thank you so much for investing so much time helping me fix my problems!

Here's my AgentMoveSystem:

Code (CSharp):

1. using Unity.Collections;
2. using Unity.Core;
3. using Unity.Entities;
4. using Unity.Mathematics;
5. using Unity.Transforms;
6.  
7. public partial class AgentMoveSystem : SystemBase
8. {
9.     protected override void OnUpdate()
10.     {
11.  
12.         float deltaTime = World.Time.DeltaTime;
13.         Random rnd = new Random();
14.         rnd.InitState(49500);
15.  
16.  
17.         AgentSpawnSettings settings = EntityManager.GetComponentData<AgentSpawnSettings>(SystemAPI.GetSingletonEntity<AgentSpawnSettings>());
18.  
19.         float3 minPos = settings.MinPos;
20.         float3 maxPos = settings.MaxPos;
21.  
22.         Entities
23.             .ForEach((ref MovementAgent agent, ref LocalTransform localTransform) =>
24.             {
25.  
26.                 localTransform.Position =
27.                 new float3(localTransform.Position.x + rnd.NextFloat(), localTransform.Position.y + rnd.NextFloat(), localTransform.Position.z);
28.  
29.                 if (localTransform.Position.y < minPos.y) localTransform.Position =
30.                     new float3(localTransform.Position.x, maxPos.y, localTransform.Position.z);
31.  
32.                 if (localTransform.Position.y > maxPos.y) localTransform.Position =
33.                     new float3(localTransform.Position.x, minPos.y, localTransform.Position.z);
34.  
35.                 if (localTransform.Position.x < minPos.x) localTransform.Position =
36.                     new float3(maxPos.x, localTransform.Position.y, localTransform.Position.z);
37.  
38.                 if (localTransform.Position.x > maxPos.x) localTransform.Position =
39.                     new float3(minPos.x, localTransform.Position.y, localTransform.Position.z);
40.  
41.  
42.             }).ScheduleParallel();
43.     }
44. }

 

I can not be sure about why you have no performance difference between the scheduling mode, but I have seen you started an other thread, and that you are in good hands. I'll let you see how to find the why in the other thread.