ComponentLookup + Entity ref vs ISharedComponentData | Official Unity Discord | Page 1

indigo forge Mar 30, 2023, 10:08 PM

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Hey. I have a lot of entities which require the same large piece of data (FooData), I was originally going to store the data on a separate entity, pass both that Entity and ComponentLookup<FooData> into parallel jobs for my large group of entities. But I was wondering if using a ISharedComponentData would be more performant? I don't have a good sense of how cheap component lookups are. The ISharedComponentData saves plumbing and juggling Entity 'references'.

Any thoughts?

Thanks for the help!

prime eagle Mar 30, 2023, 10:10 PM

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Is this data immutable?

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It sounds like a good candidate for blobs

indigo forge Mar 30, 2023, 10:13 PM

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Ya the data is immutable. Would there be benefits to using blobs rather than just having the data defined directly on the ISharedComponentData? The data isn't large enough to take up much of the chunk, but more than I want to replicate across Entities.

prime eagle Mar 30, 2023, 10:14 PM

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well shared components have other consequences

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is this data loaded from baking?

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because how do you intend to store it on the shared component

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i assume you want your shared component to be unmanaged so you can access it in jobs

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how many variations of this shared component do you have?

indigo forge Mar 30, 2023, 10:17 PM

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Probably only 10-20 variants. Each on > 10000 entities.

prime eagle Mar 30, 2023, 10:17 PM

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so you have 100-200k entities?

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well, at least the shared component won't impact your chunk utilization

indigo forge Mar 30, 2023, 10:18 PM

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10k-100k is probably a decent range estimate.

prime eagle Mar 30, 2023, 10:22 PM

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Well, I can't really think of a major red flag against using the ISCD here as long as

you can author it and it's unmanaged
your entity count is high
your variations are low
it's immutable and you don't have to do add/remove shared components at runtime
you aren't hitting the ISCD cap

indigo forge Mar 30, 2023, 10:23 PM

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Thanks for the confirmation!

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Do you have a sense of how costly or ill advised (or not) using ComponentLookups and Entity refs are to get single chunks of data into many entities across parallel jobs?

prime eagle Mar 30, 2023, 10:25 PM

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it's pretty fast but it depends on how frequent you do it

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it's going to be a faster to just have a single copy of the shared component and not have to look it up per entity if you have any decent count

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but really, you just need to benchmark your usecase for yourself

#ComponentLookup + Entity ref vs ISharedComponentData