Multiplayer

VehicleController includes built-in multiplayer state synchronization compatible with any networking framework.

Architecture

State Synchronization

The VehicleController.Multiplayer.cs partial class provides:

• GetMultiplayerState(): Captures current vehicle state for network transmission
• SetMultiplayerState(): Applies received state on remote clients
• MultiplayerState struct: Compact data structure containing all synchronized values

Synchronized data:

• Input states (steering, throttle, clutch, handbrake, gear shifts)
• Engine RPM (angular velocity)
• Light states (bit-packed integer)
• Special actions (horn, cruise control, boost, flip over, trailer attach/detach)

MultiplayerIsRemote Property

Set vehicleController.MultiplayerIsRemote = true on non-authoritative clients to:

• Disable local input processing (input.autoSetInput automatically disabled)
• Allow network state to control the vehicle
• Prevent camera switching on remote vehicles

Physics Synchronization

The multiplayer scripts synchronize vehicle state only, not physics. You must add a physics sync component from your networking framework:

Mirror: NetworkTransformReliable or NetworkRigidbodyReliable PUN2: PhotonTransformView and PhotonRigidbodyView

Supported Frameworks

Official implementations included as samples:

Mirror

Component: MirrorMultiplayerVehicle Location: Samples~/MultiplayerMirrorSample Features: Server-validated inputs, 20Hz sync rate, automatic NetworkIdentity setup

Photon Unity Networking 2

Component: PhotonMultiplayerVehicle Location: Samples~/MultiplayerPUN2Sample Features: IPunObservable implementation, configurable send/serialization rates

Custom Implementation

To implement for other frameworks:

1. Detect ownership/authority in your networking component
2. Set vehicleController.MultiplayerIsRemote = !isOwned after initialization
3. On owned client: Call GetMultiplayerState() and send via network
4. On remote clients: Receive state and call SetMultiplayerState()
5. Add physics sync component from your framework

Example pseudo-code:

void OnOwnershipDetermined()
{
    vehicleController.MultiplayerIsRemote = !IsOwned();
}

void FixedUpdate()
{
    if (IsOwned())
    {
        var state = vehicleController.GetMultiplayerState();
        SendToNetwork(state);
    }
}

void OnReceiveState(MultiplayerState state)
{
    if (!IsOwned())
    {
        vehicleController.SetMultiplayerState(state);
    }
}