Using the Runtime Spawner Fusion Pool Provider

Integrating with the Fusion Pooling system provided by Runtime Spawner

Runtime Spawner – Fusion Pool Provider Integration

How Fusion + Runtime Spawner Pooling Works

Runtime Spawner ships with a FusionPoolObjectProvider, a component that plugs directly into Fusion’s INetworkObjectProvider API.

This component must be the runner’s provider when using Runtime Spawner in Fusion mode.

Because Fusion only supports one provider per runner:

• If you previously used Fusion’s NetworkObjectProviderDefault

• Or your own custom provider → Runtime Spawner’s provider replaces it on that runner.

Runtime Spawner now owns pooling, Fusion still owns networking and authority replication.

---

What Runtime Spawner’s Fusion Pool Provider Does

With FusionPoolObjectProvider added to your NetworkRunner:

Fusion

• Calls AcquirePrefabInstance() when it needs a new instance

• Calls ReleaseInstance() when despawning a network object

Runtime Spawner

• Provides the instance from its internal pool

• Prewarms pools from SpawnEntries

• Tracks per-entry + global population caps

• Ensures proper enable/disable lifecycle for pooled instances

• Ensures networked despawn goes through Fusion first but still returns to Runtime Spawner's pool

Fusion owns the network lifecycle. Runtime Spawner owns the object pooling.

---

How to Spawn and Despawn Objects

This is the #1 point users get stuck on, so here is the definitive guidance.

---

How Spawning Works

Automatic spawning

If you’re using:

• Global spawners

• Region spawners

• Wave spawners

… then spawning is fully automatic. You do not manually call Runner.Spawn().

Runtime Spawner internally drives spawning through its factory abstraction, and the Fusion pool provider ensures that:

• Fusion sees the spawned object

• The pooled instance is reused

• Networking replication happens correctly

Users do not need to write any spawn code unless doing custom spawns.

---

Manual spawning (advanced / optional)

If your game needs to manually spawn something (e.g., player abilities, projectiles), you must go through Runtime Spawner’s factory, not Fusion directly.

Use:

var instance = RuntimeSpawner.Instance.Executor.Spawn(entry, context);

But since this is advanced, typical users do not need this.

---

How to Despawn Objects

This is the most important part for Fusion users.

There are three correct ways to despawn something:

---

1. Automatic Despawn (waves, culling, region exit)

Runtime Spawner will:

• Detect the despawn condition

• Look up the ISpawnHandle associated with the instance

• Call Runner.Despawn() (if networked)

• Return the object to the pool

• Update internal population bookkeeping

You don’t need to do anything.

---

2. Call RuntimeSpawner.Despawn(GameObject)

This is the recommended API for gameplay scripts.

RuntimeSpawner.Despawn(gameObject);

This method:

• Looks up the owning RuntimeSpawner

• Checks if the object has a Fusion ISpawnHandle

• If networked → calls handle.Despawn() → Fusion replicates despawn

• If not → returns the object to the pool

• Updates all internal population and SpawnEntry counts

This is the safest despawn method for Fusion + pooling.

---

3. Call ISpawnHandle.Despawn() yourself (advanced)

If you cached the handle from the factory you may call that directly.

Gamers rarely need to do this unless writing custom spawn flows.

---

Should I Call Runner.Despawn Myself?

Short answer: NO — not when using Runtime Spawner.

Fusion’s Runner.Despawn(obj) will only:

• Replicate destruction across network clients

• Release the instance back to the Fusion pooling system (which Runtime Spawner has replaced)

But it will not update:

• SpawnEntry population

• Global population

• Internal bookkeeping

• Owner maps

• SpawnedObject list

• Region/wave counts

This breaks spawn balancing.

Correct Pattern

Instead of:

Runner.Despawn(gameObject);

Use:

RuntimeSpawner.Despawn(gameObject);

This ensures:

✔ Fusion replication ✔ Returned to Runtime Spawner's pool ✔ Correct population tracking ✔ Wave/region/global systems stay consistent

---

Prefab-Level Lifecycle: OnEnable / OnDisable

If your old pooling system used OnSpawned/OnDespawned, convert it to:

void OnEnable() { /* init */ }
void OnDisable() { /* cleanup */ }

Runtime Spawner guarantees:

• Pooled objects are disabled when returned

• Enabled when spawned

• Re-enable calls happen for reused objects

• Works safely in Fusion scenes

Recommended uses:

• Reset health

• Reset behavior state

• Play VFX/SFX

• Re-register with AI managers

• Start movement/pathfinding logic

---

Global Hooks for Analytics / Manager Systems

You can listen to spawn/despawn events:

RuntimeSpawner.onObjectSpawned += obj => { ... };
RuntimeSpawner.onObjectCulled += obj => { ... };
RuntimeSpawner.onUpdateCurrentPopulation += count => { ... };

This replaces custom provider logic you may have had before.

---

Advanced: Wrapping the Fusion Provider

If your project used custom routing in your old provider, you can wrap the Runtime Spawner provider:

public class MyWrappedFusionProvider : MonoBehaviour, INetworkObjectProvider
{
    public FusionPoolObjectProvider rspProvider;

    public NetworkObjectAcquireResult AcquirePrefabInstance(...) {
        // pre logic
        return rspProvider.AcquirePrefabInstance(...);
    }

    public bool ReleaseInstance(...) {
        // post logic
        return rspProvider.ReleaseInstance(...);
    }
}

This is rarely needed but fully supported.

---

Migration Checklist (Updated)

When migrating from Fusion’s default pooling to Runtime Spawner:

Required

✔ Remove existing INetworkObjectProvider from the runner ✔ Add FusionPoolObjectProvider (or your wrapper) ✔ Ensure Runtime Spawner uses the Fusion factory mode

Prefab updates

✔ Move OnSpawned/OnDespawned logic → OnEnable/OnDisable ✔ Ensure your NPCs/AI reset correctly when reused

Gameplay scripts

Replace:

Runner.Despawn(gameObject);

With:

RuntimeSpawner.Despawn(gameObject);

Global systems

✔ If you track active enemies/objects → subscribe to Runtime Spawner events

Optional

✔ For manual spawns → use Runtime Spawner’s executor, not Fusion directly

---

Final Summary

How do I despawn an object?

RuntimeSpawner.Despawn(gameObject);

Should I use Runner.Despawn?

No. Runtime Spawner must route the despawn so it can:

• Update SpawnEntry population

• Update global population

• Remove bookkeeping

• Return to the internal pool

• Trigger Fusion’s network replication (if networked)

How do I spawn new enemies manually?

Typically you don’t. Spawning is handled by global, region, or wave systems. If you must, use RuntimeSpawner’s executor.

What events can I listen to?

• RuntimeSpawner.onObjectSpawned

• RuntimeSpawner.onObjectCulled

• RuntimeSpawner.onUpdateCurrentPopulation

• etc.