Struct NetworkTimeSystem

System responsible for estimating the ServerTick and InterpolationTick using the current round trip time (see NetworkSnapshotAck) and feedback from the server (see ServerCommandAge).

The system tries to keep the server tick (present on the client) ahead of the server, such that input commands (see ICommandData and IInputComponentData) are received before the server needs them for the simulation. The system speeds up and slows down the client simulation elapsed delta time to compensate for changes in the network condition, and makes the reported ServerCommandAge close to the TargetCommandSlack.

This time synchronization start taking place as soon as the first snapshot is received by the client. Because of that, until the client NetworkStreamConnection is not set in-game (see NetworkStreamInGame), the calculated server tick and interpolated are always 0.

In the case where the client and server world are on the same process, and an IPC connection is used (see IPC), some special optimizations can be applied. E.g. In this case the client should always run 1 tick per frame (server and client update in tandem).

Implements
ISystem
ISystemStartStop
ISystemCompilerGenerated
Inherited Members
Namespace: Unity.NetCode
Assembly: Unity.NetCode.dll
Syntax
[BurstCompile]
[WorldSystemFilter(WorldSystemFilterFlags.ClientSimulation|WorldSystemFilterFlags.ThinClientSimulation, WorldSystemFilterFlags.Default)]
[UpdateInGroup(typeof(InitializationSystemGroup))]
[UpdateAfter(typeof(UpdateWorldTimeSystem))]
public struct NetworkTimeSystem : ISystem, ISystemStartStop, ISystemCompilerGenerated

Properties

DefaultClientTickRate

A new ClientTickRate instance initialized with good and sensible default values.

Declaration
public static ClientTickRate DefaultClientTickRate { get; }
Property Value
Type Description
ClientTickRate

TimestampMS

Return a low precision real-time stamp that represents the number of milliseconds since the process started. In Development build and Editor, the maximum reported delta in between two calls of the TimestampMS is capped to 100 milliseconds.

Declaration
public static uint TimestampMS { get; }
Property Value
Type Description
uint
Remarks

The TimestampMS is mostly used for sake of time synchronization (for calculting the RTT).

Methods

OnCreate(ref SystemState)

Create the NetworkTimeSystemData singleton and reset the initial system state.

Declaration
[BurstCompile]
public void OnCreate(ref SystemState state)
Parameters
Type Name Description
SystemState state

OnCreateForCompiler(ref SystemState)

Declaration
public void OnCreateForCompiler(ref SystemState state)
Parameters
Type Name Description
SystemState state

OnStartRunning(ref SystemState)

Empty method, implement the Unity.Entities.ISystem interface.

Declaration
[BurstCompile]
public void OnStartRunning(ref SystemState state)
Parameters
Type Name Description
SystemState state

OnStopRunning(ref SystemState)

Reset the NetworkTimeSystemData data and some internal variables.

Declaration
[BurstCompile]
public void OnStopRunning(ref SystemState state)
Parameters
Type Name Description
SystemState state

OnUpdate(ref SystemState)

Implements all the time synchronization logic on the main thread.

Declaration
[BurstCompile]
public void OnUpdate(ref SystemState state)
Parameters
Type Name Description
SystemState state

ResetFixedTime()

Fixes any stray FixedTime values when domain reloads are disabled.

Declaration
[RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
public static void ResetFixedTime()

Implements

Unity.Entities.ISystem
Unity.Entities.ISystemStartStop
Unity.Entities.ISystemCompilerGenerated