Question: Support for multiple processes?

[amethyst]

Question: Support for multiple processes?

[TomGillen]

Legion has no built-in support for network synchronisation, and support libraries for this are not likely to turn up until Amethyst has began to adopt legion as its ECS. There is some preliminary support for entity serialisation, but it is currently difficult to selectively serialise only some entities, as you would want to do to synchronise simulations between machines. There have been some preliminary discussion on what might be needed in legion to better support uses cases like this, but for now it is best if you do not use Entity as a globally-unique identifier if you are trying to sychronise or transfer entities between different universes. Instead, you may need to define your own unique identifier and store the mapping between that any each local Entity, or store it in a component.

[SOF3]

why store the unique identifier in a component instead of a tag?

[MagicRB]

You could copy the Entites from the main World, into a temp World and serialize that. Not the best solution but not bad.

[TomGillen]

@SOF3 Tags are best used when you have values which are shared across many entities, especially if you need to be able to filter entities by that value in queries. You should avoid storing anything which is unique to an entity in a tag, as each unique combinations of tag values will get their own storage chunk. If you put a unique ID in a tag, you would end up allocating an entire chunk for every entitity, which is both wasteful of memory and will severely degrade iteration performance.

[SOF3]

@TomGillen I see. Is there any documentation that talks about this?