Official New SubScene & ConvertToEntity workflows

ah, it landed already, need to put this on your manifest:

 

I just upgraded, and the old conversion workflow doesn't work anymore of course, but figuring out the current one is somewhat complex it seems;

Code (csharp):

1. manager = World.Active.EntityManager;
2. asteroidEntityPrefab = GameObjectConversionUtility.ConvertGameObjectHierarchy(asteroidPrefab, World.Active);

I'd use to use that to convert an asteroid prefab to an entity prefab and spawn a whole bunch of those. But since World.Active is deprecated/removed that doesn't work anymore. Trying to figure out how to assign and then convert prefabs.

 

I just update Entities to preview.18 0.2.0 and I notice the following things compared with preview.0.1.1

• On version 0.1.1 was a MonoBehaviour that control GameObject conversion.
  
• On version 0.2.0 is a MonoBehaviour that injects information into a ComponentSystem that executes the conversion.
  
• On version 0.1.1 "Convert and inject" creates an entity with all of its components, without destroying the GameObject original reference.

Code (CSharp):

1. public static bool InjectOriginalComponents(World srcGameObjectWorld, EntityManager simulationWorld, Transform transform)
2.         {
3.             var convert = transform.GetComponent<ConvertToEntity>();
4.             if (convert != null && convert.ConversionMode == Mode.ConvertAndInjectGameObject)
5.             {
6.                 var entity = GameObjectConversionUtility.GameObjectToConvertedEntity(srcGameObjectWorld, transform.gameObject);
7.                 InjectOriginalComponents(simulationWorld, entity, transform);
8.                 transform.parent = null;
9.                 return true;
10.             }
11.      
12.             for (int i = 0; i < transform.childCount;)
13.             {
14.                 if (!InjectOriginalComponents(srcGameObjectWorld, simulationWorld, transform.GetChild(i)))
15.                     i++;
16.             }
17.             return false;
18.         }

• 
  
• On version 0.2.0 "Convert and inject" does the same, but at the end destroys the GameObject reference and as a consequence, the entire hierarchy is destroyed too.

Code (CSharp):

1. void Convert()
2.         {
3.             var toBeDetached = new HashSet<Transform>();
4.             var toBeDestroyed = new HashSet<GameObject>();
5.  
6.             try
7.             {
8.                 var toBeInjected = new List<Transform>();
9.  
10.                 foreach (var convertToWorld in m_ToBeConverted)
11.                 {
12.                     var toBeConverted = convertToWorld.Value;
13.  
14.                     var settings = new GameObjectConversionSettings(
15.                         convertToWorld.Key,
16.                         GameObjectConversionUtility.ConversionFlags.AssignName);
17.                    
18.                     settings.BlobAssetStore = BlobAssetStore;
19.  
20.                     using (var gameObjectWorld = settings.CreateConversionWorld())
21.                     {
22.                         toBeConverted.RemoveAll(convert =>
23.                         {
24.                             var parent = convert.transform.parent;
25.                             var remove = parent != null && parent.GetComponentInParent<ConvertToEntity>() != null;
26.                             if (remove && parent.GetComponentInParent<StopConvertToEntity>() != null)
27.                             {
28.                                 LogWarning(
29.                                     $"{nameof(ConvertToEntity)} will be ignored because of a {nameof(StopConvertToEntity)} higher in the hierarchy",
30.                                     convert.gameObject);
31.                             }
32.  
33.                             return remove;
34.                         });
35.  
36.                         foreach (var convert in toBeConverted)
37.                             toBeDestroyed.Add(convert.gameObject);
38.  
39.                         foreach (var convert in toBeConverted)
40.                             AddRecurse(gameObjectWorld.EntityManager, convert.transform, toBeDetached, toBeInjected);
41.  
42.                         GameObjectConversionUtility.Convert(gameObjectWorld);
43.  
44.                         var mappingSystem = gameObjectWorld.GetExistingSystem<GameObjectConversionMappingSystem>();
45.                         foreach (var convert in toBeInjected)
46.                             InjectOriginalComponents(mappingSystem, convert);
47.                     }
48.  
49.                     toBeInjected.Clear();
50.                 }
51.             }
52.             finally
53.             {
54.                 m_ToBeConverted.Clear();
55.  
56.                 foreach (var transform in toBeDetached)
57.                     transform.parent = null;
58.  
59.                 foreach (var go in toBeDestroyed)
60.                     UnityObject.DestroyImmediate(go);
61.             }
62.         }

Does the new "Convert and inject" behavior mean that injecting GameObjects would only serve as a placeholder for components on the unity ECS hybrid approach? If you mark a GameObject as a "Convert and Inject", it shouldn't have any children?

 

Some of these more fundamental ECS systems seem to make such restrictive assumptions that I'm starting to worry I'm going to be spending a lot of my own time having to develop my own.

What are the mechanisms for customizing this conversion workflow, in particular the built in conversions? I want to be able to author both the server and client worlds in a single subscene and perform a conversion that is specific to the needs of each particular world. As an example, the server world does not need the mesh renderer or its child information to perform its job, nor does the client world need the majority of components responsible for simulation logic.

Is it possible to convert a single subscene into multiple representations?

Multi-world setups were something being touted from the early days and I've been trying to follow this principle for a multiplayer project but so little of the currently developing workflow seems to support any of this.

 

I don't get it. I don't get many parts of this whole workflow. It's stuck between 2 worlds and one isn't even supported anymore. How should one work with hybrid objects?

I still have physics and movement code in MB world and it won't change for the time being.
Right now I just want to make a trigger that references a door. Both of those are normal scene gameobjects. Graphical representation and colliders are living in MB world, the rest is already in ECS world.
Now I'm unable to get this really easy use case to work. In 0.0.12p33 the door reference was Entity.Null, now my gameobjects dissappear.

Has anyone a solution for this within the workflow? I get this working, no problems, without the workflow so I'm kind of perplexed what I'm missing here. Should I just go back to GameObjectEntity and mostly ignore the workflow for everything that's not pure ECS?

edit: Good lord, there's a very unintuitive workaround: https://forum.unity.com/threads/0-2-0-preview-13.781937/#post-5208599
At least the GOs aren't removed anymore.

 

Thanks!

Definitely not the best solution, but works for the moment.

I'm also using the same approach. Physics, movement, and animation are based on MB world (at least until we get more info on conversion on those packages); and game logic on ECS world

 

Hello guys!
I have created a large world and convert it into 100 tiles that streaming using Subscene system (each have large number of objects like grass). And works smoothly in mobile devices.
Main problem is the entity cache files generated from subscenes takes huge memory and that is very bad when you targeting mobile platform.
Also I use Megacity demo script StreamingLogicSystem that controll RequestSceneLoaded of SubSceneStreamingSystem what happens is it load/unloads subscene but not release the memory of subscene objects [Texture,meshes].
So is there any solution or trick for this or I did something wrong?

 

Unity (I think Joachim) recently commented somewhere that the referenced assets are currently duplicated in each subscene, and this is something they are working on improving.

 

Ohh! Also can I somehow decrease the size of entity cache files that generated from subscenes? That entity cache file also get insane in memory when you have thousands of objects in each subscenes.

 

The generated asset isn't really a cache file, it is the result of the conversion ready to be loaded straight into memory. This allows you to skip the conversion and instantiating entities at runtime.. It's basically a "ready to use" block with all the entities from the subscene ready to be used.

 

So first off: all of the github links in the first post are 404, please update this.

Trying to understand subscens a bit.
When I change the Convert method on any of the objects in the subscene, such as modifying them to have an additional component, how do I force the subscene to RELOAD the cached data of the entities it contains, calling the convert method and adding the new component or removing the old one? The only way I've found is to wiggle a value on the mono, save, wiggle it back, save, then close. But if the subscene has like 4k objects in it, wiggling each of them 2 times is NOT a viable way to reload the cache.

unload->load doesn't do it.

There used to be a reload button on the subscene, it seems, but that is now gone, leaving us with no way to reload all of the entities. UNITY WAI.

My authoring script:

Code (CSharp):

1.  
2. public class PlayerAuthoring : MonoBehaviour, IConvertGameObjectToEntity
3. {
4.     public void Convert(Entity entity, EntityManager dstManager, GameObjectConversionSystem conversionSystem)
5.     {
6.         dstManager.SetName(entity, name);
7.         dstManager.AddComponent(entity, typeof(RotationEulerXYZ));
8.         dstManager.AddComponent(entity, typeof(Tag_KeepUpright));
9.     }
10. }
11.  

See video for example: https://clips.twitch.tv/SmellyAltruisticPastaTBTacoRight

Why do I have to "wiggle" a value to make unity rerun this conversion? Why isn't there a button to just reconvert every entity in the subscene anymore? Or if it just did it every time I closed the subscene? Very frustrating.

 

Add ConverterVersion attribute to your authoring component and each time you make change which needs reimport, increment the version.

This works on prefabs linked into subscene as well.

 

Will there be some attributes for customizing the behavior of the generated converters? For something like [EntityFromGameObject]

Code (CSharp):

1. [GenerateAuthoringComponent]
2. public struct MyComponent : IComponentData
3. {
4.     [EntityReferenceFromGamObject]
5.     public float Entity targetEntity;
6. }

Because currently entity references like that are often needed and it requires a custom Authoring component every time.

EDIT: Never mind that example. I just found out that it generates a prefab field for an entity field by default. (Of course..)

 

@illinar there was a bug where it threw an error when you tried to link a gameobject reference, but I believe that was fixed in 0.4? I haven't confirmed it yet though.

But Unity is aware of this and its supposed to work for both GameObjets and prefabs (dragged in from an asset folder).

Edit: Yep, Entities 0.4 has this fix. From changelog:

• Remove unnecessary & incorrect warning in DeclareReferencedPrefab when the referenced game object is a scene object

 

Hi to all. I need some advice about using ScriptableObject assets with the DOTS.

After I watched this awesome video about ScriptableObjects

I decide to use this approach within my new game project with the DOTS.

I've created a ScriptableObject asset to share my level configurations with DOTS entities and normal game objects in the scene. In DOTS side, I've converted the config asset to Blob asset by using the GameObjectConversionSystem. As far as I know, in SubScene, conversion workflow only happens when you firstly created the scene or saved the sub scene after some changes.

The problem is, when I update this config asset, it is not applied to the previously created blob asset. As far as I know, there is no way to manually triggering conversion workflow. Therefore, something like this may be so useful for this type of situations.

What would you think about this? How would you share your configs with both DOTS entities and normal game objects? Would you use ScriptableObject asset like me or what else? If you agree with me, how would you update blob assets automatically or manually after each config changes?

 

@hazarartuner
I've encountered similar issue with ECS prefabs:
https://forum.unity.com/threads/ecs-prefabs-not-updating.794466/

The only solution which worked for me was to use ConverterVersionAttribute and increment it every time I want Subscene to fully rebuild.

 

@OndrejP thank you for your help. Unfortunately that attribute seems not working for me or I'm using it wrong, not sure

I found another workaround which is not really nice but it worked. I've created a new property for my MonoBehaviour class which is named `version`. If I need to update SubScene cache, I click the `Edit` button on the SubScene, select the GameObject that I interested in, increment the version number by using Inspector window, then I click the the `Save` button on SubScene object. It generates new cache I guess and it works. But I think we still need some button like `Clear Cache` or `Force Update`. If this is not possible, at least, I need a better approach for handling configurations for both DOTS and normal game objects.

 

@hazarartuner I've tried modifying Subscene in similar manner as you, but it did not pickup changes on my prefab.
When I changed prefab, then changed Subscene which referenced that prefab and saved value in Entity Inspector still shown old value.

This is how I use the attribute.

Code (CSharp):

1.  
2. [DisallowMultipleComponent, ConverterVersion("ReimportHelper", 3)]
3. public class ReimportHelper : MonoBehaviour, IConvertGameObjectToEntity
4. {
5.     public void Convert(Entity entity, EntityManager destinationManager, GameObjectConversionSystem conversionSystem)
6.     {
7.     }
8. }
9.  

 

@OndrejP I have no idea why our solutions not work for both of us

For now, I decided to use ConvertToEntity script rather than SubScene. As far as I know, It converts entities on start and this works for me. It may be not efficient for production usage if you have lots of game objects and/or heavy conversion workflow. But I'm at the beginning of my project and I hope there will be a better solutions for our cases later. In worst case, when I am ready to production, I can change these game objects to SubScenes because my configs will no need to be changed very often.

By the way, here is my code sample (updated):

 

Hello,

I'm starting to use the subscene feature in hte editor and I have a behaviors that I think is a bug.
I put all my level asset in a sub scene (ground, trees, buildings,...) while all my gameplay (character,...) is in hte main scene.

Now when entering play mode in the editor, if the subscene is open, it works fine (my character rests on the ground through the new physics engine). But if the subscene is close, when entering play mode, the character goes rigth through the ground, as if the subscene had a distinct physics world from the main scene.

Is it the correct behaviour ? Should I do something special to "merge" the physics worls ?

 

When the scene is open that means your assets still Go which means they are not entities and have the old physics stuff. Try to install the unity.physics package from package manager which will convert their old physics components to ones compatible with ecs. If you have already installed this package:
1) try to configure their physics shape and physics body components (I think the conversion it’s not working for the old meshcollider component)
2) make sure the belongsTo and collidesWith are configured correctly in the physics shape component.
3) make sure you character collider is converted too.

 

Hi, that's not it, I'm fully working with the new components comming with the physics package.

 

do you have error when you character is converted ?
try to see if it's related to this thread.

 

Thanks for you sugesstions. Unfortunatly, no, no error during conversion.

 

Migrating to 2019.3.0f3 seems to solve the issue.

 

Ok, new issue with 2019.3.0f3 :

When using sub scene if the sub scene is open when entering play mode, position, rotation, materials are mixed up :

This also happen when not using subscene at all.

When entiring play mode with closed sub scene, or not converting the object to entities at all, everithing is fine:

 

Them links are 404 now.

 

Is there a standard way of instantiating an Entity that has a child with ConvertToEntity-(Convert And Inject Game Object) somewhere in it's hierarchy?

Example:
I have a PlayerShip prefab and one of it's children is an Engine GameObject with with Visual Effect component so that I may use VFX Graph to draw engine exhaust.
Currently I set ConvertToEntity-(Convert And Destroy) component on a PlayerShip and ConvertToEntity-(ConvertInject Game Object) and CopyTransformToGameObject components on Engine.

Situation 1 - Instantiating by putting a prefab in a scene
This works just fine. Whole hierarchy is converted to entities destroyed but Engine which is just converted and has it's transform copied every turn form accompanying entity.


Situation 2 - Instantiating by calling EntityCommandBuffer.Instantiate()
Sometimes I don't need my PlayerShip prefab spawned right away but rather as a result of some event. So I made PlayerSpawner IComponentData and accompanying PlayerSpawnerAuthoring MB with IDeclareReferencedPrefabs. Unfortunately when I spawn my PlayerShip prefab with EntityCommandBuffer.Instantiate() entities are spawned correctly but Engine GameObject that my VFX Graph is attached to doesn't.

Is there a way to instantiate GameObjects in Situation 2?
Is there an easy way to use VFX graph with Unity ECS atm or do we have to wait longer for it?

 

I'm facing an issue where the Parent and children have attached Convert To Entity script using "Convert and Inject Game Object".

Parent component gets converted and the entity is generated but the latter doesn't get converted.

 

If i remember correctly, you need add only the ConvertToEntity componend to the root object and the Hirachy will be converted.

 

Taking a standard gameobject scene I picked a group of static objects and created a subscene. When I close the subscene or run the game (or just in game view) these objects disappear. From the few videos I've seen and stuff I've read this is all that is required to turn scene objects into entities and this isn't the behavior I expected. I thought they were suppose to remain visible in the editor, but not unable to interact with them. Also obviously they should not disappear from the game view.

I must be missing a step, but I sure can't find any info on it.

 

Maybe you face the same issue I do (see a few posts up.

Or you are missing the hybrid rendering package.

 

I ended up removing all the packages and starting over. I'm not sure where it went wrong, but it's working for the most part now. Thanks for the reply

 

FYI for those interested I seem to have solve all my display issue by making everything non static and enabaling GPU instancing on all materials.

 

Now I'm not sure if there is a way to do this, but I would like a way to disable a Child entity from being parented to the Parent entity on conversion. I've found that there are cases where I do not want a Child entity to be parented to the Parent entity, usually because I plan to handle that Child entities movement in irregular sort of way.

Yes, I know, it's kind of trivial. But I feel like it would be a nice quality of life authoring feature.

 

It would be nice to have more control over the early stages of conversion in general. I know in theory you could replace the systems in the Conversion Init group, but it would be a lot nicer if there was just a callback like with Convert() about what GameObject children you actually wanted entities for and how they were related.

 

My question:
How do you get an event / callback / entity event whenever a sub-scene (or multiple sub-scenes) are loaded.

My understanding of sub-scene loading:
Sub-scenes can be sub-divided even smaller into sections, which get asynchronously streamed into the game. This means that you can't run a system that processes the sub-scenes entities until the entire sub-scene has been loaded in; However, there doesn't seem to be a way to validate when it is done loading.

Is this correct, or am I missing something?

My problem:
We're building a multiplayer game that receives some state for objects in sub-scenes when the player connects to the server. However, the connection and state messages are received before the sub-scenes are fully loaded. And I just need a way to delay a system OnUpdate until the entire sub-scene is loaded.

Possible solution:
If we can verify when a sub-scene is done loading it'd be easy to delay the connection call to the server, however, all of these systems and component states are internal. If SceneSectionStreamingSystem.StreamingStatus was publically accessible it'd help a lot.

I've looked all over, but can't seem to find a possible way to check if a sub-scene is fully loaded or not.

 

Don't have the time to look right now, but the code for SubScenes should be C#, if i remember correctly when viewing the subscene component it shows the loading state and the loaded state. There most definitely should be a way to patch into that if you examine the code for that component.

 

The SceneSectionStreamingSystem.StreamingStatus component is added to the entity, however, this is all internal, so sadly not accessible

 

Can you have multiple subscenes in a scene? Every time I create a second subscene when I close the second subscene Unity crashes.

 

Yes you can, and no that should not be happening. File a bug report, and maybe try opening the DOTS Sample and see if it happens there for you. Maybe your doing something wierd when creating the subscenes.

 

Subscenes don't get rendered on the Quest. I can see them in the editor in play mode but once I build it to the device they disappear. Does this happen to anyone else?

 

Did you use the new build pipeline? DOTS subscenes get omitted on all platforms from build if you try to build it on old/traditional build approach.

 

I didn't use the dots package. I just have the hybrid render installed. The two have a conflict of different entity package versions. is that what you mean?

 

@CWatsonT2 See these ECS sample files for the new build system, you need to use something similar or you are not going to get your DOTS subscenes on your builds: https://github.com/Unity-Technologi...s/tree/master/ECSSamples/Assets/BuildSettings

 

Should it be possible to instantiate subscenes into the world? I'm currently storing Client/Mixed/Server in different subscenes, store it as a prefab and instantiate it through GameObject when needed. However this doesn't work for built player. My thought process is that I don't want to clutter the scene with the different maps and have them "preloaded" at start, but being able to instantiate them on request.

 

I think if you step away from your problem a little there might be some extra insight to gain @Jawsarn. You might get more mileage determining what the barebones requirement for a level would be so that it could run with your setup. That might lead you to finding that you end up with a collection of assets defining what a level looks like. The main scene containing all the level geometry that can then be loaded into the appropriate worlds with maybe a subscene or two for each of the worlds you need and whatever else is handy. When you then load the level the basis of it should be as simple as just loading the scene as you would've normally done and then let the rest kick in. The important part is establishing prefabs and source scenes with all the basics already defined so that a designer can jump in and start building a new level/map. This would reduce the need to manually load and unload the scene. I am however a little unsure about what happens to the existing Entities World when a new scene is loaded, but there should be simple enough ways to pass along the data you need to that scene so that the client can connect correctly.

 

@LazyGameDevZA Sure but in the end the problem is still the same. I've moved to trying to contain the "level" i.e. sub-scenes in a normal scene instead, but I need to consider it as a resource which can be accessed by either client or server world and thus introduced reference counting and a whole lot of new scripts around it. What I consider now is if I should also split the subscenes into three normal scenes of Client, Server, and Mixed to be able to exclude the ones not required for the build later on, or if that is a non problem.

 

Has there been any progress on this, or even some sort of public roadmap? I want to be able to dynamically load pre-converted entities from addressable assets, but it makes sense to wait for the official version if possible.

 

Thank you! I totally missed this. I was able to create a build settings file (create>build>buildsettings hybrid). Do I have to assign it somehow like you do with the scriptableRenderPipelineAsset? It still doesn't show when built to the device.

EDIT: I forgot two things. The pipeline was set to hybrid instead of androidHybrid and I didn't have the classic scripting component added to the buildSettings. Also I think having all the gameobjects set to static in the subscene makes a difference.