How to efficiently apply logic to target entities

We have a lot of effects in our game (procs/triggers, health linking, homing projectiles) that require "target" entities. We currently GetComponentData and GetBuffer on the targets to apply logic on them and/or the source.

This seems like a very naive approach, and I would like to know what's the best practice for this use case.

For example, would it be better to have a separate query for these target entities and fill NativeHashMaps beforehand?

 

In general, ComponentDataFromEntity + Burst Jobs should be the recommended way of dealing with arbitrary entities. If you have a lot of extreme one-to-many relations (i.e. tons of homing missiles but only a handful of targets), then you can utilize the batch api to gain more performance.

 

Is there an equivalent of ComponentDataFromEntity for DynamicBuffers?

 

Yes, BufferFromEntity. Those are the only two *FromEntity right now. There are times I wish there are more, like ArchetypeFromEntity and ChunkFromEntity.

 

Is it possible to test a query against an entity?

 

Not sure if I follow you correctly. But inside jobs, you can use ComponentDataFromEntity.Exists() to check ComponentData existence against an entity.

https://docs.unity3d.com/Packages/c...Unity.Entities.ComponentDataFromEntity-1.html

 

It'd be nice if I could check if an entity tests true using an EntityQueryDesc, but ComponentDataFromEntity.Exists() will yield the same results if I use a few. Thanks!