Class SpeedLimiterModule

Module that enforces a maximum speed limit by controlling engine power output.

Inheritance
object
VehicleComponent
SpeedLimiterModule
Inherited Members
Namespace: NWH.VehiclePhysics2.Modules.SpeedLimiter
Assembly: NWH.VehiclePhysics2.dll
Syntax
[Serializable]
public class SpeedLimiterModule : VehicleComponent
Remarks

The SpeedLimiterModule prevents vehicles from exceeding a configured speed limit by reducing engine power to zero when the limit is reached. Unlike braking systems, this module does not apply braking force - it simply prevents further acceleration by cutting throttle authority.

How It Works: - Registers a power modifier callback with the engine - When speed exceeds the limit, returns 0 (no power) - When speed is below the limit, returns 1 (full power) - Works by multiplying the engine's power output

Use Cases: - Speed-restricted vehicles (delivery trucks, buses, construction vehicles) - Racing games with different vehicle classes and regulations - Gameplay mechanics requiring speed caps (school zones, restricted areas) - AI vehicle behavior control - Tutorial or difficulty progression systems

Behavior Notes: - Does not apply brakes - the vehicle will coast down naturally due to drag - Will not prevent downhill acceleration from gravity - Works in both forward and reverse directions (uses absolute speed) - Can be enabled/disabled at runtime for dynamic speed restrictions

Fields

active

Indicates whether the speed limiter is currently limiting power.

Declaration
public bool active
Field Value
Type Description
bool
Remarks

True when the vehicle speed exceeds the limit and power is being cut. False when the vehicle is below the speed limit.

This is a read-only status field useful for: - UI indicators showing limiter activation - Visual effects (warning lights, dashboard indicators) - Audio cues when limit is reached - Analytics or telemetry systems

speedLimit

Maximum allowed speed before the limiter cuts engine power.

Declaration
[Tooltip("Speed limit above which the throttle will be cut.")]
public float speedLimit
Field Value
Type Description
float
Remarks

The numeric value is interpreted according to speedUnits. When vehicle speed exceeds this value, throttle authority is removed.

Typical values by vehicle type (in km/h): - Delivery vans: 90-110 - Buses: 80-100 - Construction vehicles: 40-60 - Racing regulations: varies by class

Set to 0 to disable speed limiting completely.

speedUnits

Unit of measurement for the speedLimit value.

Declaration
[Tooltip("Units which will be used for speed limiter. Defaults to m/s.")]
public SpeedLimiterModule.SpeedUnits speedUnits
Field Value
Type Description
SpeedLimiterModule.SpeedUnits
Remarks

Specifies how to interpret the speed limit value: - ms: Meters per second (Unity native) - kmh: Kilometers per hour (most common) - mph: Miles per hour (US/UK)

The module automatically converts the specified unit to m/s internally. Choose the unit most familiar to your design team to avoid conversion errors.

Methods

SpeedPowerLimiter(float)

Power modifier callback that restricts engine power when speed limit is exceeded.

Declaration
public float SpeedPowerLimiter(float DeltaTime)
Parameters
Type Name Description
float DeltaTime

Time step for the current frame (unused in this modifier).
Returns
Type Description
float

Power multiplier: 1.0 (full power) when below limit, 0.0 (no power) when at or above limit.
Remarks

This method is registered as an engine power modifier and called each physics frame. It compares the current vehicle speed against the configured limit and returns a multiplier that is applied to the engine's power output.

Return values: - 1.0: Normal operation, speed is below limit - full power available - 0.0: Speed limit exceeded - no power, throttle input is ignored

The method converts the configured speed limit to m/s based on speedUnits for comparison with the vehicle's speed. This conversion happens every frame to support runtime changes to the speed limit or units.

VC_Disable(bool)

Disables the component and stops updates. Override to add component-specific disable logic.

Declaration
public override bool VC_Disable(bool calledByParent)
Parameters
Type Name Description
bool calledByParent

True if called by parent component or LOD system
Returns
Type Description
bool

True if successfully disabled, false otherwise
Overrides
Remarks

Component must be initialized before it can be disabled. Tracks whether disable was called by parent to manage LOD system interaction.

VC_Enable(bool)

Enables the component and starts updates. Override to add component-specific enable logic.

Declaration
public override bool VC_Enable(bool calledByParent)
Parameters
Type Name Description
bool calledByParent

True if called by parent component or LOD system
Returns
Type Description
bool

True if successfully enabled, false otherwise
Overrides
Remarks

Will initialize the component if not already initialized. Components disabled by LOD system will track the parent caller to prevent manual enabling while LOD is controlling state.

See Also