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Replication profile

In one line: a named kind of view a session is bound to — one observer over a set of archetypes, answered from geometry every tick.

A profile is declared once, before the runtime starts, and shared by every session bound to it. It holds exactly one entity observer:

Observer A session holds… For
World every entity of the observed archetypes, delivered progressively tools, viewer bots, small worlds
Sphere(r) the entities within r of its centre — a point the application places, an entity, or the entity it controls players
ClientRegion(maxEdge) the entities inside a convex footprint the client sends (a camera's view), up to a near budget god and strategy cameras

beside which it may declare one Aggregate: per-tile, per-archetype counts refreshed at a bounded rate — a heat map or a far tier, never entity records.

What a session holds is geometry, not a list. Nothing is stored per (session, entity): a Sphere session holds an entity when the entity's last sent position lies within the radius of the session's anchor and the replication cell it is in has been delivered to the session. A new view is filled cell by cell, nearest first, under a per-frame enter budget; a moving session receives the entities that came into range and is told about those that left.

The Sphere has refinements, all declared on the profile: a leave radius (Sphere(192, leave: 208)) so an entity jittering on the boundary does not flap in and out; a run-time range (max:) for SetRadius; distance bands that send far entities' updates less often; and a cadence (Every(2)) that serves the profile one tick in two or four. A session's outbound byte budget lowers its detail level before it ever drops state.

How it relates

  • Replication session — bound to a profile by Session(id).Profile(name).
  • Projection — the profile names archetypes (.Of<T>()); what of each travels is the projection's.
  • Spatial index — delivery and sweeps query the spatial grid; the replication cell side is declared separately (SubscriptionsOptions.ReplicationCellM).

In the API

  • ProfileBuilder — World(), Sphere(…), ClientRegion(…), Aggregate(…), Every(…), Detection(…).
  • ObserverBuilder — Of<T>(), Bind, At, AroundControlled, Near, Bands.

Learn & use

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