Why ISharedComponentData can store Mesh/Material class variables

I see in examples that you can store Mesh and Material inside ISharedComponentData. Both of them is not a struct but a class.

- Is that only few exceptions, or any class reference works with ISharedCompoenentData?
- If reference values are allowed, two ISharedComponentData struct are considered the same by comparing the class's reference address?

 

Yes any ISharedComponentData can store ref values but there's no way at the moment to pass them into a job as jobs can't have non blittable properties. AddSharedComponentData / SetSharedComponentData should be done in the main thread.

Right now I'm accessing those values via static properties which is considered hacky *gasp*.

 

I think

ISharedComponentData

allowing us to add reference to manage code is a workarround because Unity still lacks a lot of pure ECS systems, like the rendering one, which you still need Mesh and Materials classes.

What makes me think that is the way they are writing ECS to give us performance by default, which includes using the so called HPC# subset and witch does not includes references, to avoid memory aliasing.