Convert to entity is so slow

Our game agents are originally prefabs with lots of components and some hierarchy of child objects. We used GameObjectEntity to make them work with ECS. However, when I used ConvertToEntity, the game spikes whenever such prefab is instantiated. Maybe because the prefab is too big with lots of components.

Maybe I did it wrong. I applied ConvertToEntity to the child GameObjects because they're easier to convert. For now, there's like three of them. When I realized that it's slow, I surmised that maybe I don't need three ConvertToEntity components. I just need one at the parent. But when I tried this with a simple test, it doesn't work. A ConvertToEntity component added to the parent does not convert the children at all.

What are my other options? I want to get rid of GameObjectEntity because they will be deprecated soon.

 

You’re instantiating at start (automatically)? Or in process you calling ConvertGameObjectHierarchy? In second case every call creates conversion world, systems, converts thing and destroying world with systems.

 

No we're not instantiating at start. We just have a prefab that we instantiate during some interaction, say player wants to make a worker. They will click on Worker button then click on the map. That's when we instantiate the prefab. We're using a pooling asset but internally, it just uses plain old Instantiate(). Basically, I'm not sure if we're using ConvertGameObjectHierarchy. We just added ConvertToEntity component and some MBs implementing IConvertGameObjectToEntity. The current systems work fine. It just causes really high spikes.

 

Ah you just instantiate already converted prefab? I told about conversion case

 

In most cases, you'd want to convert all traditional prefabs into entity prefabs at once at the start. And just use the entity prefabs from then on.

The IConvertGameObjectToEntity API can be slow because of all the individual AddComponentData() calls.

 

Try to prevent SharedComponentData, I had huge spikes when I instantiated many entities even from a pre-converted gameobject. Instantiating around 4.6k entities took some seconds, without the SharedComponentData it was in the milliseconds again.

 

My problem with this is that custom MonoBehaviours are not added. I tried it and seems like it only adds standard components like Transform and MeshRenderer to the converted entity. This won't do because most other systems in the game rely on those MBs.

Edit: Not entirely sure if my custom MBs are not added to the converted entity but their Awake(), Start(), and Update() are not called at all.

 

You can't just have game logic in MonoBehaviors converted into ECS. Any game logic you have on the prefabs needs to be manually converted into ECS Systems.

The ConvertToEntity will handle setting up default components where possible such as Transform, Rendering, Entity Parenting, LocalToWorld calculations etc. The resulting entities are then able to be automatically updated by default ECS transform systems so you don't have to write that stuff yourself.

What you can do is implement IConvertGameObjectToEntity and in the conversion method add any components and set the values you need from the prefab.

see example here : https://github.com/Unity-Technologi...ssets/Common/Scripts/EntityKillerBehaviour.cs

 

That's a bummer then because it will take a big rewrite or refactoring to existing systems. If this is the direction of hybrid, it's not practical for existing projects that are already big.

I hope GameObjectEntity will not be eventually removed then if there's no other simple alternative.