Class AerodynamicsModule

Simulates aerodynamic drag and downforce forces on the vehicle.

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

The AerodynamicsModule calculates and applies realistic aerodynamic forces based on vehicle dimensions, speed, and drag coefficients. This affects vehicle behavior at all speeds but becomes increasingly significant as velocity increases.

Drag Forces: Drag is calculated separately for longitudinal (forward/backward) and lateral (side-to-side) motion using the standard aerodynamic drag equation: F = 0.5 * rho * A * Cd * v^2, where: - rho: Air density (1.225 kg/m³ at sea level) - A: Frontal or side area (calculated from vehicle dimensions) - Cd: Drag coefficient (frontalCd or sideCd) - v: Velocity in the respective direction

The quadratic relationship means drag increases dramatically at high speeds. For example, doubling speed results in 4x the drag force, creating natural speed limitations.

Downforce: Downforce can be applied at multiple points on the vehicle to increase tire grip at high speeds. This is particularly useful for race cars and high-performance vehicles. Downforce increases quadratically from 0 to the configured maximum downforce speed, then remains constant beyond that. Position downforce points low on the vehicle (near wheel height) to avoid destabilizing pitch effects.

Damage Integration: The module integrates with the vehicle's damage system. When damaged, additional drag is applied to simulate compromised aerodynamics from bent panels, broken spoilers, etc. This creates a tangible performance penalty for vehicle damage.

For more information visit: https://nwhcoding.com/VehiclePhysics/manual/AerodynamicsModule.html

Fields

RHO

Air density constant in kg/m³ at sea level and 15°C. Used in aerodynamic force calculations.

Declaration
public const float RHO = 1.225
Field Value
Type Description
float

damageDragEffect

Additional drag multiplier applied when the vehicle is fully damaged.

Declaration
[Range(0, 5)]
[Tooltip("The amount of drag that will be added when the vehicle is fully damaged.\r\n0.5 equals +50% on top of the original, undamaged, drag value.")]
public float damageDragEffect
Field Value
Type Description
float
Remarks

Simulates the aerodynamic penalty from damaged bodywork, broken spoilers, and compromised aero components. A value of 0.5 means the vehicle experiences 50% additional drag on top of the original undamaged drag value when fully damaged. Partial damage scales linearly.

Recommended values: - 0.0-0.2: Minor aerodynamic penalty (scratches, minor dents) - 0.3-0.5: Moderate performance loss (default: 0.5) - 0.6-1.0: Significant drag increase (severe damage, missing panels)

downforcePoints

List of points on the vehicle where downforce will be applied.

Declaration
[Tooltip("Points at which downforce will be applied.\r\nAvoid applying force at too high positions as that will negatively influence suspension and steering.")]
public List<DownforcePoint> downforcePoints
Field Value
Type Description
List<DownforcePoint>
Remarks

Each point defines a location and maximum force value. Downforce at each point increases quadratically with speed up to maxDownforceSpeed. Multiple points allow distributing downforce to tune handling balance (understeer/oversteer).

Positioning Guidelines: - Place points low on the vehicle (near wheel height or floor level) - Avoid high positions that create excessive pitch moments - Typical configuration: One point at front axle, one at rear axle - Front-biased downforce reduces understeer at speed - Rear-biased downforce reduces oversteer and improves stability

Visible as red sphere gizmos in the Scene view when module is selected.

frontalCd

Coefficient of drag (Cd) for the vehicle's frontal area.

Declaration
[Range(0, 1)]
[Tooltip("Coefficient of drag of the vehicle's frontal profile.\r\nAlso used for reverse.")]
public float frontalCd
Field Value
Type Description
float
Remarks

Applied to forward and reverse motion. Lower values reduce drag and improve top speed and acceleration, while higher values increase air resistance.

Real-world reference values: - Sports cars: 0.25-0.35 - Sedans: 0.3-0.4 - SUVs/Trucks: 0.35-0.5 - Buses/Large vehicles: 0.6-0.8

The frontal area is automatically calculated from vehicle dimensions as: width * height * 0.85 (accounting for rounded edges and ground clearance).

maxDownforceSpeed

Speed in m/s at which downforce reaches its maximum configured value.

Declaration
[Tooltip("Speed in [m/s] at which the downforce will reach it's maximum value\r\nassigned under downforce points settings.")]
public float maxDownforceSpeed
Field Value
Type Description
float
Remarks

Downforce increases quadratically from 0 to this speed, then remains constant above it. Lower values make downforce more effective at lower speeds, which is useful for circuit racing where top speeds may be limited.

Recommended values: - Street cars: 50-80 m/s (180-288 km/h) - Race cars: 40-60 m/s (144-216 km/h) - High-speed cars: 80-100 m/s (288-360 km/h)

Set this based on the typical top speed of your vehicle. As a rule of thumb, set it to 80-90% of maximum achievable speed.

sideCd

Coefficient of drag (Cd) for the vehicle's side profile.

Declaration
[Range(0, 2)]
[Tooltip("Coefficient of drag of the vehicle's side profile.")]
public float sideCd
Field Value
Type Description
float
Remarks

Affects resistance to lateral movement (sideways sliding, drifting, crosswinds). Typically higher than frontal Cd due to the less aerodynamic side profile.

Higher values increase: - Stability in crosswinds - Resistance to drifting and sliding - Cornering grip feel (via reduced slip velocity)

Lower values allow: - Easier drifting - More responsive to lateral forces - More susceptible to crosswinds

Typical values: 0.8-1.5 for most vehicles. The side area is automatically calculated from vehicle dimensions as: height * length * 0.8.

simulateDownforce

Enables downforce calculation and application.

Declaration
[Tooltip("Should downforce be calculated?")]
public bool simulateDownforce
Field Value
Type Description
bool
Remarks

Enable for race cars and high-performance vehicles where aerodynamic grip is important. Disable for regular road vehicles to save computation and avoid unrealistic behavior. When disabled, downforce points are ignored.

simulateDrag

Enables aerodynamic drag calculation.

Declaration
[Tooltip("Should drag be calculated?")]
public bool simulateDrag
Field Value
Type Description
bool
Remarks

Should generally be enabled for realistic vehicle behavior. Disabling removes air resistance, which will result in unrealistically high top speeds and lack of deceleration when coasting. Only disable for arcade-style games or debugging purposes.

Methods

VC_DrawGizmos()

Draws debug gizmos in the Scene view when the vehicle is selected. Override to visualize component-specific debug information.

Declaration
public override void VC_DrawGizmos()
Overrides
Remarks

Only called in Editor when the component is enabled. Use Gizmos and Handles API to draw debug visualizations.

VC_FixedUpdate(float)

Physics update called at fixed intervals. Override to implement physics-based behavior.

Declaration
public override void VC_FixedUpdate(float DeltaTime)
Parameters
Type Name Description
float DeltaTime

Time elapsed since last FixedUpdate in seconds
Overrides
Remarks

Only called when the component is active (initialized and enabled). Use for physics calculations, force application, and other fixed-timestep operations. Called from VehicleController.FixedUpdate().

VC_Initialize()

Initializes the component's internal systems and resources. Called once during vehicle startup after the VehicleController reference is set.

Declaration
protected override void VC_Initialize()
Overrides
Remarks

Override this to set up component-specific resources, cache references, or perform one-time initialization. Sets state.initialized to true on completion.

See Also