Struct ClientServerTickRate

The ClientServerTickRate singleton is used to configure the client and server simulation time step, server packet send rate and other related settings. The singleton entity is automatically created for the clients in the NetworkStreamReceiveSystem first update if not present. On the server, by countrary, the entity is never automatically created and it is up to the user to create the singletong instance if they need to. This behaviour is asymmetric because the client need to have this singleton data synced with the server one. It is like this for compatibility reason and It may be changed in the future. In order to configure these settings you can either:

It is not mandatory to set all the fields to a proper value when creating the singleton. It is sufficient to change only the relevant setting, and call the ResolveDefaults() method to configure the fields that does not have a value set. class MyCustomClientServerBootstrap : ClientServerBootstrap { override public void Initialize(string defaultWorld) { base.Initialise(defaultWorld); var customTickRate = new ClientServerTickRate(); //run at 30hz customTickRate.simulationTickRate = 30; customTickRate.ResolveDefault(); foreach(var world in World.All) { if(world.IsServer()) { //In this case we only create on the server, but we can do the same also for the client world var tickRateEntity = world.EntityManager.CreateSingleton(new ClientServerTickRate { SimulationTickRate = 30; }); } } } } The ClientServerTickRate settings are synced as part of the of the initial client connection handshake. (ClientServerTickRateRefreshRequest data). The ClientServerTickRate should also be used to customise other server only timing settings, such as

See the individual fields documentation for more information.
Implements
IComponentData
IQueryTypeParameter
Inherited Members
Namespace: Unity.NetCode
Assembly: Unity.NetCode.dll
Syntax
[Serializable]
public struct ClientServerTickRate : IComponentData, IQueryTypeParameter

Fields

MaxSimulationStepBatchSize

If the server cannot keep up with the simulation frequency with running MaxSimulationStepsPerFrame ticks it is possible to allow each tick to run with a longer delta time in order to keep the game time updating correctly. This means that instead of running two ticks with delta time N each, the system will run a single tick with delta time 2*N. It is a less expensive but more inaccurate way of dealing with server performance spikes, it also requires the game logic to be able to handle it.

Declaration
public int MaxSimulationStepBatchSize
Field Value
Type Description
int

MaxSimulationStepsPerFrame

If the server updates at a lower rate than the simulation tick rate it will perform multiple ticks in the same frame. This setting puts a limit on how many such updates it can do in a single frame. When this limit is reached the simulation time will update slower than real time. The network tick rate only applies to snapshots, the frequency commands and RPCs is not affected by this setting.

Declaration
public int MaxSimulationStepsPerFrame
Field Value
Type Description
int

NetworkTickRate

The rate at which the server sends snapshots to the clients. This can be lower than than the simulation frequency which means the server only sends new snapshots to the clients every N frames. The effect of this on the client is similar to having a higher ping, on the server it will save CPU time and bandwidth.

Declaration
public int NetworkTickRate
Field Value
Type Description
int

PredictedFixedStepSimulationTickRatio

Multiplier used to calculate the tick rate/frequency for the PredictedFixedStepSimulationSystemGroup. The group rate must be an integer multiple of the SimulationTickRate. Default value is 1, meaning that the PredictedFixedStepSimulationSystemGroup run at the same frequency of the prediction loop. The calculated frequency is 1.0/(SimulationTickRate*PredictedFixedStepSimulationTickRatio)

Declaration
public int PredictedFixedStepSimulationTickRatio
Field Value
Type Description
int

SimulationTickRate

The fixed simulation frequency on the server and prediction loop. The client can render at a higher or lower rate than this.

Declaration
public int SimulationTickRate
Field Value
Type Description
int

TargetFrameRateMode

If the server is capable of updating more often than the simulation tick rate it can either skip the simulation tick for some updates (BusyWait) or limit the updates using Application.TargetFrameRate (Sleep). Auto makes it use Sleep for dedicated server builds and BusyWait for client and server builds (as well as the editor).

Declaration
public ClientServerTickRate.FrameRateMode TargetFrameRateMode
Field Value
Type Description
ClientServerTickRate.FrameRateMode

Properties

ClampPartialTicksThreshold

On the client, Netcode attempts to align its own fixed step with the render refresh rate, with the goal of reducing Partial ticks, and increasing stability. Defaults to 5 (5%), which is applied each way: I.e. If you're within 5% of the last full tick, or if you're within 5% of the next full tick, we'll clamp. -1 is 'turn clamping off', 0 is 'use default'. Max value is 50 (i.e. 50% each way, leading to full clamping, as it's applied in both directions).

Declaration
public int ClampPartialTicksThreshold { readonly get; set; }
Property Value
Type Description
int
Remarks

High values will lead to more aggressive alignment, which may be perceivable (as we'll need to shift time further).

PredictedFixedStepSimulationTimeStep

The fixed time used to run the physics simulation. Is always an integer multiple of the SimulationFixedTimeStep.
The value is equal to 1f / (SimulationTickRate * PredictedFixedStepSimulationTickRatio).

Declaration
public float PredictedFixedStepSimulationTimeStep { get; }
Property Value
Type Description
float

SendSnapshotsForCatchUpTicks

If the server has to run multiple simulation ticks in the same frame the server can either send snapshots for all those ticks or just the last one.

Declaration
public bool SendSnapshotsForCatchUpTicks { get; set; }
Property Value
Type Description
bool

SimulationFixedTimeStep

1f / SimulationTickRate. Think of this as the netcode version of fixedDeltaTime.

Declaration
public float SimulationFixedTimeStep { get; }
Property Value
Type Description
float

Methods

ResolveDefaults()

Set all the properties that hasn't been changed by the user or that have invalid ranges to a proper default value. In particular this guarantee that both NetworkTickRate and SimulationTickRate are never 0.

Declaration
public void ResolveDefaults()

Implements

Unity.Entities.IComponentData
Unity.Entities.IQueryTypeParameter

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