Question List of prefabs with access in editor (with GenerateAuthoringComponent?)

Hey all!

Im trying to make an list (or array) of prefabs in editor so i can acces the enitities in runtime with DOTS/ECS.

It worked with one enitity but now im trying to make an list of all the prefabs I have.

Any solutions?

This is my working solution now with one entity:

Code (CSharp):

1. using Unity.Entities;
2.  
3. [GenerateAuthoringComponent]
4. public struct EntityGamePrefabs : IComponentData
5. {
6.     public Entity EntitiesPrefabs;
7. }

 

Code (CSharp):

1.     using Unity.Entities;
2.  
3.     [GenerateAuthoringComponent]
4.     public struct EntityGamePrefab : IBufferElementData
5.     {
6.         public Entity EntityPrefab;
7.     }
8.  

 

thanks for the suggestion it seems I cant acces it in the editor so i cant put my Prefabs in there.. See the picture.

Any suggestion?





And it gives an error :

Code (CSharp):

1. NullReferenceException: Object reference not set to an instance of an object
2. Unity.Entities.Hybrid.BufferElementAuthoring`2[TBufferElementData,TWrappedValue].Convert (Unity.Entities.Entity entity, Unity.Entities.EntityManager destinationManager, GameObjectConversionSystem _) (at

 

Found an solution from this talk:

timestamp 23:28

Monoclass script :

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using Unity.Entities;
4. using UnityEngine;
5.  
6. public class PrefabsHolder : MonoBehaviour, IConvertGameObjectToEntity, IDeclareReferencedPrefabs
7. {
8.     public GameObject[] prefabs;
9.  
10.     public void DeclareReferencedPrefabs(List<GameObject> referencedPrefabs)
11.     {
12.         referencedPrefabs.AddRange(prefabs);
13.     }
14.  
15.     public void Convert(Entity entity, EntityManager dstManager, GameObjectConversionSystem conversionSystem)
16.     {
17.         var buffer = dstManager.AddBuffer<EntityGamePrefabs>(entity);
18.  
19.         foreach (var prefab in prefabs)
20.         {
21.             buffer.Add(new EntityGamePrefabs { EntitiesPrefabs = conversionSystem.GetPrimaryEntity(prefab) });
22.         }
23.     }
24. }
25.  
26.  
27.  

Buffer:

Code (CSharp):

1.  
2. using System;
3. using System.Collections.Generic;
4. using Unity.Entities;
5. using UnityEngine;
6.  
7. [GenerateAuthoringComponent]
8. public struct EntityGamePrefabs : IBufferElementData
9. {
10.     public Entity EntitiesPrefabs;
11. }
12.  

Acces buffer:

Code (CSharp):

1. EntityQuery m_Query = GetEntityQuery(typeof(EntityGamePrefabs));
2. entityWithPrefabs = m_Query.GetSingletonEntity();
3. DynamicBuffer<EntityGamePrefabs> GamePrefabs = entityManager.GetBuffer<EntityGamePrefabs>(entityWithPrefabs);
4.  

This is an working solution but i hope someday GenerateAuthoringComponent will work with dynamic buffers..

 

Hmm... seems like a bug with when using "Entity" as the field, if you replace it with other serializable type (like int or float) it works just fine.

 

Ok thanks! Where can I report an bug?

 

The usual Bug Reporter from Unity

 

This solution no longer works unfortunately. Trying to get a singleton by IBufferElementData elements no longer works.

I instead added a "PrefabCollectionTag" to the Gameobject and .GetSingleton<PrefabCollectionTag>()

EDIT: The buffer never gets added to the entity anymore. Using this approach in a Sub Scene does not work.

"ArgumentException: A component with type:EntityGamePrefabs has not been added to the entity." - when trying to access the buffer on the entity

EDIT 2: For anyone else trying to figure out how to spawn prefabs programmatically in ECS and are shocked to find there are 0 examples of how to do this with Sub Scenes here is a working example: https://forum.unity.com/threads/prefab-workflow-and-managing.968299/#post-6675886