Fusion Local Area Spawner Driver

Photon Fusion Extension for the Local Area Spawner (New in 1.6.0)

Overview

FusionLocalAreaSpawnerDriver is the Photon Fusion driver for LocalAreaSpawner that replicates inside/outside state using Fusion’s authority model.

Key behavior:

• Trigger detection runs only on the peer(s) allowed by executionTarget.

• State replication is always sent from StateAuthority via an RPC.

• All clients apply the region state locally by calling:

  • LocalAreaSpawner.SetPlayerInRegion(bool)

This keeps region presence consistent across all peers while still allowing flexible “who runs detection” policies.

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Requirements

• Photon Fusion installed (FUSION_WEAVER)

• A NetworkObject on the same GameObject (required)

• A LocalAreaSpawner component (same object or child)

• A trigger collider configured for detection (commonly the BoxCollider on the LocalAreaSpawner object)

• LocalAreaSpawner should be set to ActivationMode.External (recommended)

• Scene must be running in play mode (driver uses runtime trigger callbacks and Fusion ticks)

This driver enforces NetworkObject via:

• [RequireComponent(typeof(NetworkObject))]

It is also ordered early:

• [DefaultExecutionOrder(-50)]

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Inspector Reference

Detection

Activator Tag (playerTag) Optional tag filter. If set, only colliders matching this tag are considered valid activators. Leave empty to disable tag filtering.

Matching checks include:

• Collider tag

• Attached Rigidbody GameObject tag

• Root transform tag

Activator Layers (activationLayers) Optional layer mask filter. Leave as Everything to accept any layer.

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Execution

Execution Target (executionTarget) Controls who is allowed to execute detection logic and participate in broadcasting.

Options and meaning:

• Everyone

  • Trigger callbacks can run everywhere (useful for local-only behaviors)

  • Replication still only originates from StateAuthority (see below)

• StateAuthorityOnly

  • Only the peer with StateAuthority processes trigger callbacks

• ServerOnly

  • Only a dedicated server peer runs detection (will be false in modes without a server)

• SharedModeMasterClientOnly

  • In Shared Mode, allows the “master client” semantics, and also allows StateAuthority

Important: regardless of this setting, the driver guards replication with Object.HasStateAuthority.

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Debug

Enable Logging (enableLogging) Enables log output.

Verbosity (logVerbosity)

• ErrorsOnly

• Normal

• Verbose (includes early-outs + filter decisions)

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Authority & Replication Model

Detection authority (configurable)

Detection occurs via Unity trigger callbacks:

• OnTriggerEnter

• OnTriggerStay (safety net for missed enters/teleports)

• OnTriggerExit

These callbacks only proceed when:

• CanExecuteOnThisPeer() is true (based on executionTarget), and

• Object.HasStateAuthority is true

So even if executionTarget is Everyone, the driver will not accept triggers unless the peer is StateAuthority.

Replication (always from StateAuthority)

Inside/outside is replicated to all peers using an RPC:

[Rpc(RpcSources.StateAuthority, RpcTargets.All)]
private void RpcSetInside(bool inside, RpcInfo info = default)
{
    _region.SetPlayerInRegion(inside);
}

This ensures:

• One authoritative source of truth

• Deterministic, consistent region state across all clients

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Runtime Behavior

On Spawned()

When the NetworkObject spawns:

• The driver resolves the LocalAreaSpawner reference (GetComponent or child)

• It forces the region to false (not inside) initially:

  • _region.SetPlayerInRegion(false)

• It resets internal state tracking:

  • _isInsideAuth = false

  • _lastSentInside = false

This prevents stale state from previous sessions / scene replays.

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Trigger detection (StateAuthority only)

When a valid activator collider enters/stays/exits:

• If accepted, the driver updates _isInsideAuth

• It applies the change immediately on the authority peer:

  • _region.SetPlayerInRegion(inside)

This gives instant local feedback on authority before replication arrives elsewhere.

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Network tick replication (send-on-change)

In FixedUpdateNetwork():

• If the peer can execute and has StateAuthority:

• If _isInsideAuth differs from _lastSentInside:

  • Updates _lastSentInside

  • Sends RpcSetInside(_isInsideAuth) to all peers

This avoids spamming RPCs; it only sends when the inside state changes.

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Applying replicated state (all peers)

When RpcSetInside is received:

• The driver resolves the LocalAreaSpawner again (safe for late component init)

• Calls:

  • _region.SetPlayerInRegion(inside)

This triggers:

• LocalAreaSpawner.onPlayerIsInRegion(region, inside)

• Trigger UnityEvents (OnTriggerEnterEvent, etc.)

• Region UnityEvents (OnRegionEntered, etc.) …based on your 1.6.0 LocalAreaSpawner implementation.

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Recommended Setup

1. Add a LocalAreaSpawner with a BoxCollider trigger volume

2. Set LocalAreaSpawner Trigger Driver Mode to External

3. Add a NetworkObject to the same GameObject as the driver

4. Add FusionLocalAreaSpawnerDriver

5. Configure:

   • Activator Tag (optional)

   • Activator Layers

   • Execution Target (typically StateAuthorityOnly)

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Common Troubleshooting

Region never activates

• Confirm the object has StateAuthority on the peer you expect

• Confirm the trigger collider is actually firing (Rigidbody presence, correct layers)

• Confirm activationLayers includes the player collider’s layer

• If playerTag is set, confirm it matches the player object/root/rigidbody object

Region flickers active/inactive

• Multiple colliders may be entering/exiting rapidly (e.g., child colliders)

• Restrict activationLayers

• Use a tag filter

• Prefer a single “activation collider” on the player

I set ExecutionTarget = Everyone but it still doesn’t work on clients

That’s expected: this driver still requires Object.HasStateAuthority to accept trigger callbacks and replicate state. ExecutionTarget affects eligibility checks, but StateAuthority remains the source of truth.