Class Steering

Converts steering input into per-wheel steer angles, with Ackermann geometry on two-wheel axles, speed-sensitive angle and rate reduction, and visual steering wheel animation. Front and rear steering both come from the wheel group steer coefficients.

Inheritance

object

VehicleComponent

Steering

Inherited Members

VehicleComponent.state

VehicleComponent.vehicleController

VehicleComponent.IsActive

VehicleComponent.VC_Initialize(VehicleController)

VehicleComponent.VC_LoadStateFromStateSettings()

VehicleComponent.VC_Enable(bool)

VehicleComponent.VC_DrawGizmos()

VehicleComponent.UpdateLOD()

VehicleComponent.ToggleState()

Namespace: NWH.VehiclePhysics2

Assembly: NWH.VehiclePhysics2.dll

Syntax

[Serializable]
public class Steering : VehicleComponent

Fields

angle

Current steering angle in degrees applied to the wheels.

Declaration

[ShowInTelemetry(NaN, NaN, null, null, 1)]
[Tooltip("Current steer angle.")]
public float angle

Field Value

Type	Description
float

Remarks

Post-processing angle: speed-sensitive curve, rate limit and smoothing already applied. Positive is right, negative is left, normally within +/- maximumSteerAngle.

assistCounterSteerReward

Reduces assist when player is already counter-steering correctly (0-1). Higher values reduce intervention more when the player is already correcting.

Declaration

[Range(0, 1)]
[Tooltip("Reduces assist when player counter-steers correctly. 0 = no reduction, 1 = full reduction.")]
public float assistCounterSteerReward

Field Value

Type	Description
float

assistCounterSteerThreshold

Counter-steering angle in degrees at which the full counter-steer reward applies.

Declaration

[Range(1, 10)]
[Tooltip("Counter-steering angle (deg) for the full reward. Smaller corrections receive a partial reward.")]
public float assistCounterSteerThreshold

Field Value

Type	Description
float

assistDerivativeGain

Derivative gain for the steering assist PD controller. Higher values dampen oscillations but may reduce responsiveness.

Declaration

[Range(0, 1)]
[Tooltip("Derivative gain (kD). Dampens oscillations.")]
public float assistDerivativeGain

Field Value

Type	Description
float

assistDerivativeSmoothing

Smoothing time for the derivative term to reduce noise/jitter.

Declaration

[Range(0, 0.1)]
[Tooltip("Derivative smoothing time (seconds). Reduces noise/jitter.")]
public float assistDerivativeSmoothing

Field Value

Type	Description
float

assistMaxAngle

Maximum steering correction in degrees before strength, activation and reward scaling.

Declaration

[Tooltip("Maximum correction angle (degrees) before assist strength, activation and counter-steer reward scale it down.")]
public float assistMaxAngle

Field Value

Type	Description
float

assistMinSpeed

Minimum planar speed in m/s for assist. Blends to full strength at twice this speed.

Declaration

[Tooltip("Minimum ground-plane speed (m/s). Assist blends in up to twice this speed, while grounded and moving forward.")]
public float assistMinSpeed

Field Value

Type	Description
float

assistOutputSmoothing

Smoothing time for the assist output angle.

Declaration

[Range(0, 0.2)]
[Tooltip("Output smoothing time (seconds). Prevents sudden corrections.")]
public float assistOutputSmoothing

Field Value

Type	Description
float

assistProportionalGain

Proportional gain for the steering assist PD controller. Higher values increase response to current slip angle.

Declaration

[Range(0.1, 2)]
[Tooltip("Proportional gain (kP). Controls response to current slip angle.")]
public float assistProportionalGain

Field Value

Type	Description
float

assistSlipThreshold

Slip angle in degrees where assist starts blending in, reaching full strength at twice this angle.

Declaration

[Tooltip("Assist starts at this slip angle and blends to full strength at twice the angle (degrees).")]
public float assistSlipThreshold

Field Value

Type	Description
float

assistSpeedCurve

Assist strength by planar speed. X = 0-50 m/s normalized to 0-1, Y = multiplier (0-1).

Declaration

[Tooltip("Assist strength by ground-plane speed. X: 0-50 m/s normalized, Y: strength multiplier.")]
public AnimationCurve assistSpeedCurve

Field Value

Type	Description
AnimationCurve

counterSteerRateMultiplier

Multiplier for steering rate when counter-steering (steering opposite to vehicle slip). Higher values allow faster corrections during oversteer recovery.

Declaration

[Range(1, 5)]
[Tooltip("Steering speed multiplier when counter-steering. 2-4x recommended for keyboard.")]
public float counterSteerRateMultiplier

Field Value

Type	Description
float

counterSteerSlipThreshold

Vehicle slip angle threshold in degrees before counter-steer rate boost activates.

Declaration

[Tooltip("Slip angle threshold before counter-steer rate boost activates.")]
public float counterSteerSlipThreshold

Field Value

Type	Description
float

damage

Current damage level of the steering system (0-1). Affects max angle and causes offset.

Declaration

[NonSerialized]
[Tooltip("Current steering system damage (0-1).")]
public float damage

Field Value

Type	Description
float

damageAngleReduction

Maximum steering angle reduction at full damage (0-1). 0.3 = 30% angle reduction at damage=1.

Declaration

[Range(0, 0.5)]
[Tooltip("Inert as shipped - steering damage is never raised. Maximum steering angle reduction at full damage (0-1).")]
public float damageAngleReduction

Field Value

Type	Description
float

Remarks

Inert as shipped. Steering.damage is only ever reset to 0 - DamageHandler raises damage on the engine, the transmission and the wheels only - so this multiplies a permanent zero.

damageSteeringOffset

Maximum steering offset (pull) in degrees at full damage. Vehicle will pull to one side.

Declaration

[Range(0, 15)]
[Tooltip("Inert as shipped - steering damage is never raised. Maximum steering offset (pull) in degrees at full damage.")]
public float damageSteeringOffset

Field Value

Type	Description
float

Remarks

Inert as shipped. Steering.damage is only ever reset to 0 - DamageHandler raises damage on the engine, the transmission and the wheels only - so this multiplies a permanent zero.

degreesPerSecondLimit

Maximum steering rate in degrees per second. Applies whenever useRawInput is false. 0 or less removes the limit.

Declaration

[Tooltip("Limits how fast the wheels can steer, in degrees per second. Applies whenever Raw Input is off. E.g. 60 deg/s means wheels with a 30 degree steer angle take 1 second to go from full left to full right. Set to 0 to remove the limit.")]
[ShowInSettings("deg/s Limit", 50, 500, 10)]
public float degreesPerSecondLimit

Field Value

Type	Description
float

Remarks

Stands in for power steering response time. 60-120 deg/s simulates a heavy vehicle; 300-500 deg/s simulates a sports car. At 30° max steer angle and 180 deg/s, full lock to lock takes 0.33 s.

externallyAddedAngle

Additional steering angle added to the final steering calculation. Bypasses all input processing, smoothing, and rate limiting.

Declaration

[Tooltip("    angle added to the user set angle, used mostly for motorcycle balancing.\r\n    To add angle to the current steer angle use this instead of angle, since this goes around smoothing and clamping.")]
public float externallyAddedAngle

Field Value

Type	Description
float

Remarks

Added straight onto the processed angle with no smoothing or clamping, so use this rather than writing to angle for external steering sources: motorcycle balance, lane keep, stability systems.

linearity

Curve defining the relationship between steering input (0-1) and steering angle response (0-1). Controls the non-linearity of steering input to provide more precise control around center.

Declaration

public AnimationCurve linearity

Field Value

Type	Description
AnimationCurve

Remarks

X is normalized input (0 center, 1 full), Y normalized angle (0 straight, 1 max). Default is linear. An S-curve gives finer control around centre, a progressive curve dulls the centre and sharpens the extremes.

maximumSteerAngle

Maximum steering angle in degrees that the wheels can achieve. Defines the vehicle's turning radius and maneuverability.

Declaration

[Range(0, 90)]
[ShowInSettings("Max. Steer Angle", 5, 50, 5)]
[Tooltip("Maximum steering angle at the wheels.")]
public float maximumSteerAngle

Field Value

Type	Description
float

Remarks

Angle at full input, before the speed-sensitive curve cuts it back at speed. Compact car 30-35°, sedan 25-30°, SUV or truck 35-45°, racing car 15-25°.

returnToCenter

Controls whether wheels automatically return to center position when no steering input is applied.

Declaration

[ShowInSettings("Return to Center")]
[Tooltip("Should wheels return to neutral position when there is no input?")]
public bool returnToCenter

Field Value

Type	Description
bool

Remarks

Off holds the last angle until new input arrives, for manual or externally driven centering.

smoothTime

Time in seconds for steering to reach its target angle. Uses SmoothDamp to give steering a sense of momentum.

Declaration

[Range(0.01, 0.3)]
[ShowInSettings("Smooth Time", 0.01, 0.3, 0.01)]
[Tooltip("Time in seconds for steering to reach target. Lower = faster response, higher = smoother/heavier feel.")]
public float smoothTime

Field Value

Type	Description
float

Remarks

Sports car 0.04-0.06 s, sedan 0.06-0.10 s, truck or SUV 0.10-0.15 s.

smoothing

Not read. Serialized only so prefabs that already carry the key deserialize cleanly.

Declaration

[HideInInspector]
[Obsolete("Not read. Use smoothTime.")]
public float smoothing

Field Value

Type	Description
float

speedSensitiveSteeringCurve

Curve defining how maximum steering angle is reduced with vehicle speed for improved stability. X-axis represents normalized speed (0-1 = 0-50 m/s), Y-axis represents steering multiplier (0-1).

Declaration

[Tooltip("Curve that shows how the steering angle behaves at certain speed.\r\nX axis represents velocity in range 0 to 50m/s (normalized to 0,1).\r\nY axis represents 0 to maximumSteerAngle (normalized to 0,1).")]
public AnimationCurve speedSensitiveSteeringCurve

Field Value

Type	Description
AnimationCurve

Remarks

Multiplies maximumSteerAngle by speed. Default is 1.0x at 0 km/h, 0.4x at ~54 km/h (0.3 normalized) and 0.2x at 180 km/h (1.0 normalized). Acts as a variable steering ratio: the visual steering wheel is rendered from the pre-curve angle, so it does not move on its own as speed changes.

speedSensitiveSteeringRateCurve

Curve defining how steering rate is reduced with vehicle speed. X-axis: normalized speed (0-1 = 0-50 m/s), Y-axis: rate multiplier (0-1).

Declaration

[Tooltip("Curve that reduces steering rate at higher speeds. X: speed (0-50m/s normalized), Y: rate multiplier (0-1).")]
public AnimationCurve speedSensitiveSteeringRateCurve

Field Value

Type	Description
AnimationCurve

Remarks

This curve multiplies the smoothing value based on vehicle speed. Lower values at high speed mean slower steering response, which helps keyboard players maintain control at highway speeds. Only affects steering input rate, not return-to-center behavior.

steeringAssistStrength

Strength of steering assist (0 = disabled, 1 = full assist). Automatically adds counter-steer when vehicle is sliding to help maintain control.

Declaration

[Range(0, 1)]
[ShowInSettings("Assist Strength", 0, 1, 0.1)]
[Tooltip("Steering assist strength. 0 = disabled, 1 = full assist. Helps counter-steer during slides.")]
public float steeringAssistStrength

Field Value

Type	Description
float

steeringWheel

Transform of the visual steering wheel object that will be rotated to match steering input. Leave null if no visual steering wheel rotation is needed.

Declaration

[Tooltip("Steering wheel transform that will be rotated when steering. Optional.")]
public Transform steeringWheel

Field Value

Type	Description
Transform

Remarks

Rotated about its local Z by angle times steeringWheelTurnRatio. Model the wheel in the straight-ahead position; the initial local rotation is cached and used as the base.

steeringWheelTurnRatio

Multiplier that converts steering wheel angle to visual steering wheel rotation. Controls how many degrees the visual steering wheel rotates relative to the actual wheel steering angle.

Declaration

[Tooltip("Steer angle will be multiplied by this value to get steering wheel angle. Ignored if steering wheel is null.\r\nIf you want the steering wheel to rotate in opposite direction use negative value.")]
public float steeringWheelTurnRatio

Field Value

Type	Description
float

Remarks

Stands in for the steering box reduction; real cars run 10:1 to 20:1. Sports car 12-15, sedan 16-18, truck 20-24, racing car 8-12. Negative flips the rotation direction for models authored the other way round.

useRawInput

Controls whether steering input is processed or applied directly to the wheels. When enabled, bypasses all smoothing, rate limiting, and speed-sensitive adjustments.

Declaration

[ShowInSettings("Raw Input")]
[Tooltip("If true direct steering input will be used, without any modification.")]
public bool useRawInput

Field Value

Type	Description
bool

Remarks

True maps input straight to wheel angle, for arcade handling, debugging or custom processing. False routes it through smoothing, speed sensitivity, the linearity curve and the rate limit, which is what gamepad and keyboard input needs.

Methods

CalculateSteerAngles(float)

Calculates and applies steering angles to all wheel groups based on current input and vehicle state. Handles input processing, speed sensitivity, Ackermann geometry, and rate limiting.

Declaration

public virtual void CalculateSteerAngles(float DeltaTime)

Parameters

Type	Name	Description
float	DeltaTime	Time elapsed since the last update, used for rate limiting calculations

CalculateWheelbase()

Calculates the wheelbase (distance between front and rear axles) for the current vehicle configuration.

Declaration

public float CalculateWheelbase()

Returns

Type	Description
float	Wheelbase distance in meters, or -1 if fewer than two wheels carry a WheelController

Remarks

Longitudinal separation of the front-most and rear-most axle centres, taken from wheelController.transform.localPosition.z - the same source WheelGroup uses for trackWidth. Covers any axle count, and being the local z rather than a 3D distance it carries no track or ride-height component. Used for Ackermann calculations.

VC_Disable(bool)

Disables the component and stops its updates.

Declaration

public override bool VC_Disable(bool calledByParent)

Parameters

Type	Name	Description
bool	calledByParent	True when called by a parent ManagerVehicleComponent fan-out or the VehicleController enable/disable loop. The LOD system passes false.

Returns

Type	Description
bool	True if successfully disabled, false otherwise

Overrides

VehicleComponent.VC_Disable(bool)

Remarks

Refused on a component that is not initialized. Records whether the call came from a parent, which is what VC_Enable checks before a bulk re-enable.

VC_FixedUpdate(float)

Fixed-timestep update for forces, torques and other physics work. Called from VehicleController.FixedUpdate(), and only while the component is active.

Declaration

public override void VC_FixedUpdate(float DeltaTime)

Parameters

Type	Name	Description
float	DeltaTime	Time elapsed since last FixedUpdate in seconds

Overrides

VehicleComponent.VC_FixedUpdate(float)

VC_Initialize()

One-time setup, once per vehicle startup and after the VehicleController reference is set. Sets state.initialized on completion; an override that fails must leave it false.

Declaration

protected override void VC_Initialize()

Overrides

VehicleComponent.VC_Initialize()

VC_SetDefaults()

Writes default values into every serialized field, and may pull default assets from Resources. Runs on vehicle reset and when the component is first added.

Declaration

public override void VC_SetDefaults()

Overrides

VehicleComponent.VC_SetDefaults()

VC_Update(float)

Per-frame update for input, visuals and UI. Only called while the component is active. Physics belongs in VC_FixedUpdate, not here.

Declaration

public override void VC_Update(float DeltaTime)

Parameters

Type	Name	Description
float	DeltaTime	Time elapsed since last Update in seconds

Overrides

VehicleComponent.VC_Update(float)

VC_Validate(VehicleController)

Editor-side configuration check: null references, out-of-range values, missing dependencies. Reports through Debug.LogWarning/LogError.

Declaration

public override void VC_Validate(VehicleController vc)

Parameters

Type	Name	Description
VehicleController	vc	Parent VehicleController to validate against

Overrides

VehicleComponent.VC_Validate(VehicleController)

VisualUpdate()

Updates the visual steering wheel rotation to match the current steering angle. Called each frame to keep visual elements synchronized with the steering state.

Declaration

public virtual void VisualUpdate()

Remarks

Rotates the steering wheel Transform around Z-axis by angle * steeringWheelTurnRatio. No-op if no steering wheel is assigned.