Why use GameObjectConversionSystem over IConvertGameObjectToEntity

Wondering if someone could explain to me why I would ever use GameObjectConversionSystem over IConvertGameObjectToEntity. It feel like if the general pattern is to use GameObject to author entities it should be very explicit by implementing the IConvertGameObjectToEntity.

Thanks in advance

 

GameObjectConversionSystem vs IConvertGameObjectToEntity is similar to IJobChunk vs IJobForEach.

GameObjectConversionSystem gives you the ability to take into account combinations of authoring components and exclusions of components as well as Unity built-in components. [RequiresEntityConversion] is how you can explicitly declare a component as an authoring component even if it isn't an IConvertGameObjectToEntity.

 

Thanks for the reply. I’m still not 100% clear , what do you mean by combination, exclusion and build in. Do you have a code example I can compare. Is it the fact that it runs after IConvertGameObject giving you a hook to all entity data for further processing ?

 

Combination and Exclusion, you get to write Entities.ForEach and can create a custom query of GameObject components. For example, if I got a character component on a GameObject but no AI or or PlayerControl components, I might want to add a simple ECS component that loops the idle animation.

As for built-in, I am writing a custom physics solution and being able to convert PhysX colliders into my custom data representations is awesome and something I couldn't do nearly as easily without GameObjectConversionSystem. Additional hook points are also really nice.

 

Got it , thanks for the explanation