No Instancing
- It breaks genre continuity: hospitals, schools, shops — all reduced to isolated spaces.
- Zois don’t transition naturally: no deferred routing, no simulation memory.
- You can’t model a living city: everything becomes disconnected and dead on arrival.
Instancing is a shortcut for devs who don’t want to deal with real simulation. It’s a stage prop, not a world.
Using with World Partitioning (Unreal Engine built-in)
An approach that can exist without a loading screen is only possible if the entire simulation runs within a single world and the same instance.
It’s called World Partitioning — one simulation zone gets unloaded, another one loads in, bringing back the agents that were dormant there. Zois can cross zones using streamable navmesh — this approach is known as a Persistent World with deferred activation.
That’s why it’s best to use predictable paths between them (like bridges) to keep navmesh as simple as possible. It’s similar to how lot transitions work in Sims 3, where access is only from the front.
It demands proxy simulation for dormant zones and semantic routing based on tags.
Skylines-Style Global Simulation
- Global event simulation: accidents, illness, routing work regardless of zone visibility.
- Zoi pool: agents activate on demand, then unload when done.
- Services as agents: ambulances, police, transit respond to needs, not presence.
This is how you simulate a living city (not by faking it with instanced scenes and frozen logic).
Skylines-style global simulation + World Partitioning for spatial fidelity
→ One seamless world, architecturally optimized through zones
The simulation runs seamlessly across zones, with each area dynamically loading or unloading based on player interaction and agent activity.
→ Zois live as agents, activated by semantics and events
Zois exist as persistent agents within this unified world, but they are only activated when triggered by semantic tags or events.
→ Hospitals receive patients even when their zone sleeps via proxy logic or event routing
Even when a zone is dormant, its institutions (like hospitals) remain logically accessible. Under this approach, if you’re heading to a hospital located in another zone, the previous zone goes dormant, and the new one activates. Zois from other zones (patients) can still arrive via Ambulance proxy simulation or event-based routing, regardless of zone activity. if they previously carried tags like “injured,” “sink”, or “medical”.
This approach preserves simulation trust, supports emergent behavior, and enables optimization without sacrificing architectural honesty.