Networked Transform Component

The plNetworkedTransformComponent replicates a game object's position and rotation across the network with smooth snapshot interpolation. It supports client authority, meaning the owning client drives the transform and broadcasts it to all peers.

Overview

This component is the primary way to synchronize object positions in a multiplayer game. It is suitable for player characters, NPCs, projectiles, or any moving object that does not use rigid body physics.

On the authoritative machine (the owner), the component captures the object's transform each tick and sends it at the configured send rate. On remote machines, incoming snapshots are fed into an adaptive-rate interpolator that produces smooth, jitter-free rendering.

No physics plugin dependency is required. For physics-based objects, use Networked Rigidbody Component instead.

Properties

Property	Type	Default	Description
`m_fSendRate`	`float`	`20.0`	How many state updates per second to send (Hz)
`m_fTeleportThreshold`	`float`	`5.0`	Distance threshold above which the object snaps instead of interpolating
`m_bSyncVelocity`	`bool`	`true`	Whether to include derived velocity in state updates

How It Works

Authority Side (Owner)

Each frame, UpdateAsAuthority() captures the current transform via CaptureTransformState().
At the configured m_fSendRate, the component writes position, rotation, and velocity into a TransformState message and sends it.
In host mode, the state is broadcast to all clients. In client mode, it is sent to the host for relay.

Remote Side (Non-Owner)

Incoming TransformState messages are received via HandleTransformStateMessage().
Each snapshot is pushed into a plNetworkInterpolator with a synthetic timestamp for smooth spacing.
Each frame, UpdateAsRemote() advances the interpolator timeline and calls ApplyRemotePosition() and ApplyRemoteRotation() to update the game object.

Teleport Detection

If the distance between the current interpolated position and the next target exceeds m_fTeleportThreshold, the component snaps instantly rather than interpolating. This handles respawns, level transitions, or large corrections.

Virtual Hooks

The component provides virtual methods that subclasses can override for custom behavior:

Method	Purpose
`OnAuthorityDetermined(bIsLocal)`	Called once when authority is resolved. Use to set up cameras, input, first/third person, etc.
`UpdateAsAuthority()`	Called each frame on the owner. Override to inject input or physics before capturing state.
`UpdateAsRemote()`	Called each frame on remotes. Override for custom interpolation or prediction.
`CaptureTransformState()`	Reads the current transform into replicated state fields. Override to add custom state.
`ApplyRemotePosition(vPosition)`	Applies a received position. Default calls `SetGlobalPosition()`. Override for physics-aware teleports.
`ApplyRemoteRotation(qRotation)`	Applies a received rotation. Default calls `SetGlobalRotation()`.

Example: Character Controller Override

class MyCharacterNetTransform : public plNetworkedTransformComponent
{
protected:
  void ApplyRemotePosition(const plVec3& vPosition) override
  {
    // Use character controller teleport instead of direct position set
    m_pCharacterController->RawMove(vPosition - GetOwner()->GetGlobalPosition());
  }
};

Interpolation

The component uses plNetworkInterpolator internally, which provides:

Adaptive-rate playback-- Speeds up or slows down slightly to absorb network jitter.
Zero extrapolation-- Holds the last known position rather than predicting, preventing overshoot.
Configurable delay-- Default 100ms buffer for 20 Hz sends.

See Snapshot Interpolation for details on the interpolation algorithm.

Usage

Add plNetworkedTransformComponent to any prefab that should have its transform replicated.
Spawn the prefab using the Object Manager.
The owning client's transform is automatically replicated to all other machines.

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