Scripting: Client vs Simulator

When scripting Simulators, we need mechanisms to tell them apart.

Am I a Simulator ?

Ask Coherence.SimulatorUtility.IsSimulator.

using Coherence;
using UnityEngine;

public class SimulatorClass : MonoBehaviour
    public void Awake()
        if (SimulatorUtility.IsSimulator)
            // I'm a simulator!

There are two ways you can tell coherence if the game build should behave as a Simulator:

  • COHERENCE_SIMULATOR preprocessor define.

  • --coherence-simulation-server command-line argument.

Connect and ConnectionType

The Connect method on Coherence.Network accepts a ConnectionType parameter.

using Coherence;
using Coherence.Connection;
using Coherence.Toolkit;
using UnityEngine;

public class ConnectAsSimulator : MonoBehaviour
    void Start()
        var endpoint = new EndpointData
            region = EndpointData.LocalRegion,
            host = "",
            port = 32001,
            schemaId = RuntimeSettings.instance.SchemaID,

        var bridge = FindAnyObjectByType<CoherenceBridge>();
        bridge.Connect(endpoint, ConnectionType.Simulator);



// simulator-specific code


Whenever the project compiles with the COHERENCE_SIMULATOR preprocessor define, coherence understands that the game will act as a Simulator.

Command-line argument

Launching the game with --coherence-simulation-server will let coherence know that the loaded instance must act as a Simulator.

You can supply additional parameters to a Simulator that define its area of responsibility, e.g. a sector/quadrant to simulate Entities in and take authority over Entities wandering into it.

You can also build a special Simulator for AI, physics, etc.

Server-side simulation

You can define who simulates the object in the CoherenceSync inspector.

Connecting Simulators automatically to RS: AutoSimulatorConnection Component

coherence includes an auto-connect MonoBehaviour out of the box for Room- and World-based Simulators. The Component its called AutoSimulatorConnection.

When you add the Component, it will parse the connection data passed with Command-line arguments to connect to the given Replication Server automatically. This will also work for Simulators you upload to the coherence Cloud.

Multi-Room Simulators have their own per-scene reconnect logic. The AutoSimulatorConnection components should not be enabled when working with Multi-Room Simulators.

If the Simulator is invoked with the --coherence-play-region parameter, AutoSimulatorConnection will try to reconnect to the Server located in that region.

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