Sodium w/ Entity Component System?

dakom 2019-04-08 09:12:51 UTC #1

@clinuxrulz I remember you mentioning this somewhere...

What would be the relationship between an entity-component-system and sodium?

At a glance it almost looks like there is no difference (Cell is entity, what it holds is components, gets evaluated/updated via stream/snapshot) - but unless I'm mistaken an ECS doesn't have a strict hierarchy necessarily - i.e. you can have easy sibling<->sibling communication...

Not sure if I really have a specific question, just haven't been able to do much lately and this is on the back of my mind for when I can get back into it

clinuxrulz 2019-04-09 21:16:06 UTC #2

A quick sketch. Just take notice of Line for now. Ignore Arc and Circle.

gist.github.com

https://gist.github.com/clinuxrulz/53b37177cd0e13a4b598a9af6986b15b

EcsTHREESceneUpdater.ts

import * as sodium from 'sodiumjs';
import * as THREE from 'three';
import { EcsComponentType } from './EcsComponentType';
import { EcsReadOnlySceneContext } from './EcsReadOnlySceneContext';
import { EcsSceneChanges } from './EcsSceneChanges';
import { IsEcsComponentValue } from './IsEcsComponentValue';
import { ArcComponent } from './components/ArcComponent';
import { Axes2DComponent } from './components/Axes2DComponent';
import { CircleComponent } from './components/CircleComponent';
import { Line3DComponent } from './components/Line3DComponent';

This file has been truncated. show original

This code is basically ILC (cSceneCtxOp / sSceneChanges). And it is somewhat related to another post about incremental updates of threejs scene without ILC.

Notice that updates to the same line only get observed once the line has been added to threejs.

Also note the sample code is not yet complete. I need to disconnect stuff on componentsUnset(). But hope it is enough to get an idea.

clinuxrulz 2019-04-09 21:21:12 UTC #3

Ah. You mean the systems?

data System = System (Cell ReadOnlySceneCtx -> Stream SceneChanges -> Stream (IO ()))

But you may squeeze in a few more callbacks in the system type signature (e.g. init() / cleanup())

EcsTHREESceneUpdater is an example of a system.

Just roughing it out on my phone. Going to be at the beach (gold coast) for the next 3 days.

clinuxrulz 2019-04-09 21:52:01 UTC #4

Sorry. I Think I missread the question as "how to integrate ecs with sodium" instead of like "how is sodium like ecs".

clinuxrulz 2019-04-30 22:53:13 UTC #5

After experimenting, the method I described above does not scale very well. It gets very slow with a few 100 entities (even when the lines are a single geometry). You get much better performance using a imperative class to do incremental updates in bulk, then pass along the bulk results with sodium.

clinuxrulz 2019-05-01 10:06:44 UTC #6

One scalability issues for per entity sodium objects is from n sodium objects recieving a message, and n-1 sodium objects saying "not for me". The can be resolved with the router combinator (cuts down on noise in the network) found in the original C++ implementation. Its implementation works in a single transaction, but since we do not have access to internals a 2 transaction version would be fine.