Svelte Demo
Quirky Starfish

Arena: area-of-interest culling

A 2400x1600 world with ~150 server-driven NPCs, but your client only receives what is inside a 420-unit radius around you - live.smooth({ interest }) culls the rest per subscriber, with LOD bands throttling the fringe. Move with WASD or arrow keys; your dot is predicted through the shared apply, so it responds on the same frame.

Arena interest area centered on the cameraThe dashed ring begins the low-frequency fringe at 300 units; delivery stops at the solid 420-unit ring.
WASD / arrows to move
Touch controls

Interest HUD

receiving 0 of 0 entities (0% culled)

you NPC another visitor

fringe starts at 300 delivery stops at 420

Freshness (per remote entity, view.freshness(key)):

live coasting stale

Fringe entities (beyond 300 units) update every 6th tick, the mid ring every 3rd - watch dots dim as they coast between updates. The 420-unit rim is taller than this viewport, so some received dots remain beyond its top and bottom edges. Walk toward a quiet corner and the receiving count drops; the world does not.