Can I transfer a resource from the main world to the render world?

[Supreeeme]

I have some non Clone, non Sync data (wrapped in SyncCell) that I'd like to transfer from my main app to the render app. Is there a good way to go about doing this? Alternatively, is there a good way to initialize a resource one time in the render world?

[Supreeeme]

Okay, I seem to have accomplished this by adding a system to ExtractSchedule with the MainWorld resource as a parameter:

let render_app = app.sub_app_mut(RenderApp);
render_app.add_systems(ExtractSchedule, get_comms.run_if(check_comms))

// ...

fn check_comms(maybe_comms: Option<Res<Comms>>) -> bool {
    maybe_comms.is_none()
}

fn get_comms(mut commands: Commands, mut world: ResMut<MainWorld>) {
    let comms = world.remove_resource::<Comms>().unwrap();
    commands.insert_resource(comms);
}

And now I can add a system to the render app that uses Comms. Not sure if there is a better way but works for me.

[NewUser69420]

hi hi, i just saw your answer and wondered if there is also a feature working the other way around?
getting info from a compute shader and inserting it back into the mainworld?

[tombh]

I thin that's a bit more complicated: https://github.com/bevyengine/bevy/blob/main/examples/shader/gpu_readback.rs