Best way to represent multiple entities?

[LukeWood]

First of all, great work on miniplex. It is awesome.

Second, how do we represent multiple types of entities? Do we just do:

type PlayerEntity {
    position: Vector3;
}

type Terrain {
    position: Vector3;
    vertices: Vector3[];
    terrain: boolean;
}
ecs = new World<PlayerEntity | Terrain>()

Is that how we're meant to do these sorts of things? Then...

const terrains = ecs.with("vertices", "position", "terrain")

[verybomb]

I might be misinterpreting your example but iirc you're supposed to define the ecs state like this:

interface State {
  position?: Vector3 // shared component between player & terrain etc
  velocity?: Vector3
  player?: boolean
  terrain?: {
    // terrain properties (idk if vertices is supposed to be unique to the terrain component)
    vertices: Vector3
  }
}

const ecs = new World<State>()

const players = ecs.with('position', 'player')
const terrains = ecs.with('position', 'terrain')

You can also chain archetypes:

const movableObjects = ecs.with('position', 'velocity')
const players = movableObjects.with('player')

[LukeWood]

Ok I’m understanding much better now. I think I was missing a core concept of ECS