ComponentData using EntityQuery in Bootstrap

Wondering if there is a way to get component data in my bootstrap class from a cache entity using a EntityQuery.

Code (CSharp):

1.            
2.  
3.             query = new EntityQueryDesc
4.             {
5.                 Any = new ComponentType[] { typeof(HexSphereBuildDataComponent) }, // any
6.                 None = Array.Empty<ComponentType>(), // none
7.                 All = Array.Empty<ComponentType>(), // all
8.             };
9.  
10.             qBuildData = em.CreateEntityQuery(query);
11.            
12.              // ??????????????
13.              // egHexSphereBuildDataComponent bdc =  EmtilyManager.GetComponentDataFromEntityQuery
14.              // ??????????
15.  

Thanks

 

You can use World.Active.EntityManager.GetComponentData<T>(cachedEntity). This will return a copy of the component data you'd like to process on in your bootstrapper.

 

Thanks for the reply, I thing I tried going down that path but wasn’t able to workout how to get the Entity outside of a system.

Any help would be appreciated

 

Well if you wanted to get an entity outside of a system:

You can create an EntityQuery via the EntityManager:

EntityQuery query = World.Active.EntityManager.CreateEntityQuery(<some component types>);

Or by getting it from a system

EntityQuery query = World.Active.GetExistingSystem<T>().Some_Public_Query_Youve_Made;

EntityQuery[] dependencyQueries = World.Active.GetExistingSystem<T>().EntityQueries;

And from there you can get a NativeArray of Entities:

NativeArray<Entity> entities = query.ToEntityArray(Allocator.TempJob);

Once you have your entities you can grab the component data via EntityManager.

 

Thanks heaps for this

 

Im going to go with an EntityQuery via the EntityManager.

But wanted to learn how going through the system works in particular World.Active.GetExistingSystem<T>().Some_Public_Query_Youve_Made

Ive tried searching web and doc to educate myself but no luck, where did you find information no how this works? Make me think there is a whole bunch of stuff I can handle better

 

So what I mean with Some_Public_Query_Youve_Made is you create a public EntityQuery in OnCreate() callback, so e.g

Code (CSharp):

1. public ASystem : ComponentSystem {
2.   public EntityQuery uniqueQuery;
3.  
4.   protected override void OnCreate() {
5.     uniqueQuery = CreateEntityQuery(<component-types>);
6.   }
7.   ...
8. }

Because you're storing the query as a public variable you can access it like so in a bootstrapper.

var query = World.Active.GetExistingSystem<ASystem>().uniqueQuery;

 

Ahh ok got it. Thanks for clarifying

 

Do I need to do something special for Entities that were created with subscenes. I can see them in the editor before I hit play but cant access them in my bootstrap class. My EntityQuery is always 0. Are they in a different world and if so how do I access another world?

View attachment 444872

Code (CSharp):

1.      
2.  
3.         [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
4.         public static void InitializeBeforeScene()
5.         {
6.             em = World.Active.EntityManager;// EntityManager manages all entities in world
7.             EntityQuery query = World.Active.EntityManager.CreateEntityQuery(typeof(HexSphereBuildDataComponent));
8.  
9.             NativeArray<Entity> entities = query.ToEntityArray(Allocator.TempJob);
10.             Debug.Log(entities.Length + "______"); // This is 0 ?????
11.        
12.             for (int i = 0; i < entities.Length; i++)
13.             {
14.                 HexSphereBuildDataComponent data =        World.Active.EntityManager.GetComponentData<HexSphereBuildDataComponent>(entities[i]);
15.             }
16.             entities.Dispose();
17.         }
18.  

 

I haven't played around with subscenes yet. But I'm wondering if using

[RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]

runs before the subscene has been loaded which can potentially be your problem. What happens if you tried the query in an update loop? How many entities do you get?

 

Im using liveLink so the entities are in the scene before run time. What is weird is if you look at the image i posted you can see im not in play mode and the entities are in "Editor Word". Im a bit loss on this one.

EDIT query returns 0 length

 

So I just went over the basic docs on subscenes: https://github.com/Unity-Technologies/EntityComponentSystemSamples/tree/master/Samples/Assets/HelloCube/4. SubScene

Since you have the RuntimeInitializationLoadType.BeforeSceneLoad attribute, would it be the fact that the subscene hasn't been streamed in yet?

Taken from the docs
"You can load a Sub Scene automatically on play. You can also defer loading until you stream the SubScene in from code (Using the RequestSceneLoaded component)

By default, Sub Scenes are loaded from the Entity binary files, even in the editor."

The EditorWorld entities would be the subscene streamed into the editor so you can edit, make tweaks and eventually save to.

But I can try in a few days so I can actually play with Subscenes and give you a better answer.

 

Ive tried everything I can think of. Everything from RequestSceneLoaded tag to

var sys = GetOrCreateSystem<Unity.Scenes.SubSceneStreamingSystem>();
EntityQuery query = sys.World.EntityManager.CreateEntityQuery(typeof(HexSphereBuildDataComponent));

I either get 0 or I get the Entity subScene, Any ideas, seems like it should be straight forward getting existing entities created w sub-scenes using live link