Class Airfoil

Represents a finite wing that simulates aerodynamic forces using section-based calculations. Supports 1500+ airfoil profiles, automatic mesh fitting, control surface integration, and mirroring for symmetric aircraft. The airfoil is divided into spanwise sections, with each section calculating local lift, drag, and moment forces.

Inheritance

object

Object

Component

Behaviour

MonoBehaviour

Airfoil

Namespace: NWH.Aerodynamics.Airfoils

Assembly: NWH.Aerodynamics.dll

Syntax

[Serializable]
public class Airfoil : MonoBehaviour

Remarks

The airfoil uses a finite plane geometry defined by four corner points and divides it into multiple sections along the span. Each section independently calculates aerodynamic forces based on local flow conditions. Control surfaces (ailerons, rudders, etc.) are treated as separate airfoils attached to the main airfoil.

Fields

aTransform

Custom simplified Transform implementation used for positioning the Airfoil.

Declaration

[Tooltip("Custom simplified Transform implementation used for positioning the Airfoil.")]
public AirfoilTransform aTransform

Field Value

Type	Description
AirfoilTransform

aerodynamicCenterChordPosition

Position of the aerodynamic center along the chord line where lift force is applied. Value of 0 is the leading edge (front), 1 is the trailing edge (rear). Typically 0.25 (25% chord) for most airfoils.

Declaration

[Range(0, 1)]
[Tooltip("Position of the aerodynamic center along the chord line.")]
public float aerodynamicCenterChordPosition

Field Value

Type	Description
float

airfoilProfile

AirfoilProfile asset containing the lift, drag, and moment curves for this airfoil. Defines aerodynamic characteristics based on angle of attack.

Declaration

[Tooltip("AirfoilProfile that determines the performance of this airfoil.")]
public AirfoilProfile airfoilProfile

Field Value

Type	Description
AirfoilProfile

controlAngle

Deflection angle in degrees from the neutral position. Only applies if this is a control surface. Positive values typically deflect downward/right, negative values deflect upward/left depending on orientation.

Declaration

[Tooltip("Deflection angle from the original position if the Airfoil is a control surface.")]
public float controlAngle

Field Value

Type	Description
float

controlSurfaceAirfoils

Airfoils attached to this airfoil that represent control surfaces, such as ailerons, rudders, ailerators, etc.

Declaration

[Tooltip("    Airfoils attached to this airfoil that represent control surfaces, such\r\n    as ailerons, rudders, ailerators, etc.")]
public List<Airfoil> controlSurfaceAirfoils

Field Value

Type	Description
List<Airfoil>

dragCenterChordPosition

Position along the chord line where drag force is applied. Value of 0 is the leading edge, 1 is the trailing edge. Typically 0.25-0.5 for most airfoils.

Declaration

[Range(0, 1)]
[Tooltip("Position of the aerodynamic center along the chord line.")]
public float dragCenterChordPosition

Field Value

Type	Description
float

dragCoefficient

Overall multiplier for drag force. Scales the drag calculated from the airfoil profile curves. Values below 1.0 reduce drag, above 1.0 increase drag. Default 1.0.

Declaration

[Tooltip("Coefficient of drag generated by airfoil.")]
public float dragCoefficient

Field Value

Type	Description
float

fPlane

Defines the planform shape of the airfoil using four corner points (a, b, c, d). Used to calculate wing area, span, chord length, and section geometry.

Declaration

[Tooltip("FinitePlane that determines the dimensions of the airfoil.")]
public FinitePlane fPlane

Field Value

Type	Description
FinitePlane

isControlSurface

True if the airfoil is a control surface (rudder, elevator, etc.). Should only be true if the Airfoil is attached to another Airfoil.

Declaration

[Tooltip("    True if the airfoil is a control surface (rudder, elevator, etc.).\r\n    Should only be true if the Airfoil is attached to another Airfoil.")]
public bool isControlSurface

Field Value

Type	Description
bool

liftCoefficient

Overall multiplier for lift force. Scales the lift calculated from the airfoil profile curves. Values below 1.0 reduce lift, above 1.0 increase lift. Default 1.0.

Declaration

[Tooltip("Coefficient of lift generated by airfoil.")]
public float liftCoefficient

Field Value

Type	Description
float

mirrorControlAirfoils

Should control airfoils be mirrored to the mirroring target?

Declaration

[Tooltip("Should control airfoils be mirrored to the mirroring target?")]
public bool mirrorControlAirfoils

Field Value

Type	Description
bool

mirrorSlicingPoints

Should slicing points be mirrored to the mirroring target?

Declaration

[Tooltip("Should slicing points be mirrored to the mirroring target?")]
public bool mirrorSlicingPoints

Field Value

Type	Description
bool

mirroringTarget

GameObject to which the Airfoil will be mirrored. Optional.

Declaration

[Tooltip("GameObject to which the Airfoil will be mirrored. Optional.")]
public GameObject mirroringTarget

Field Value

Type	Description
GameObject

momentCoefficient

Overall multiplier for pitching moment. Scales the moment calculated from the airfoil profile curves. Values below 1.0 reduce moment, above 1.0 increase moment. Default 0.0 (disabled).

Declaration

[Tooltip("Coefficient of moment/torque generated by airfoil.")]
public float momentCoefficient

Field Value

Type	Description
float

sections

Sections/slices of the airfoil. Airfoil is sliced into smaller sections/slices and each section is then simulated individually.

Declaration

[Tooltip("    Sections/slices of the airfoil.\r\n    Airfoil is sliced into smaller sections/slices and each section is then simulated individually.")]
public List<AirfoilSection> sections

Field Value

Type	Description
List<AirfoilSection>

sliceCount

Number of spanwise divisions for the airfoil. Results in sliceCount+1 AirfoilSections. Typical range 4-10. Higher values improve accuracy at the cost of performance.

Declaration

[Tooltip("    Number of slices along the airfoil. Will result in sliceCount+1 AirfoilSections.\r\n    Using higher number will produce somewhat higher quality simulation but will\r\n    impact performance in linear fashion.")]
public int sliceCount

Field Value

Type	Description
int

Remarks

Each additional slice adds one more physics calculation per frame. 4 slices = 5 sections, suitable for small wings. 10 slices = 11 sections, suitable for large wings or wings with significant spanwise variation.

slicingPoints

Local X-axis positions where the airfoil is divided into sections. Always sorted from smallest to largest. Automatically generated by GenerateSlicingPoints() based on sliceCount.

Declaration

[Tooltip("Slicing points along the local X axis, always in order from smaller to larger value.")]
public List<float> slicingPoints

Field Value

Type	Description
List<float>

targetRigidbody

Rigidbody to which the forces are applied.

Declaration

[Tooltip("Rigidbody to which the forces are applied.")]
public Rigidbody targetRigidbody

Field Value

Type	Description
Rigidbody

Methods

AutoSetup()

Automatically configures the airfoil by analyzing the mesh geometry and creating optimal section divisions.

Declaration

public void AutoSetup()

Remarks

Performs the following steps in order:

1. Resets geometry to defaults
2. Orientates the airfoil plane to match the mesh surface
3. Fits the finite plane corners to the mesh bounds
4. Generates slicing points based on sliceCount
5. Creates airfoil sections from the slicing points

FindControlSurfaces()

Declaration

public void FindControlSurfaces()

FitToMesh()

Adjusts the finite plane corner points to match the mesh bounding area in the airfoil's local space.

Declaration

public void FitToMesh()

Remarks

Finds the four corner vertices of the mesh that correspond to the wing's planform corners. The corners are projected onto the airfoil plane and aligned to ensure parallel leading/trailing edges. This creates an accurate representation of the wing's planform shape for force calculations. Requires a MeshFilter component on the parent GameObject.

Flip()

Declaration

public void Flip()

GenerateSlicingPoints()

Generates spanwise positions where the airfoil will be divided into sections.

Declaration

public void GenerateSlicingPoints()

Remarks

Creates evenly-spaced slicing points along the local X-axis between the wing root and tip. The number of points is determined by sliceCount, resulting in sliceCount+1 sections. Points are automatically sorted and aligned with the finite plane geometry.

LinePlaneIntersection(Vector3, Vector3, Vector3, Vector3)

Declaration

public static Vector3 LinePlaneIntersection(Vector3 planePoint, Vector3 planeNormal, Vector3 linePoint, Vector3 lineDirection)

Parameters

Type	Name	Description
Vector3	planePoint
Vector3	planeNormal
Vector3	linePoint
Vector3	lineDirection

Returns

Type	Description
Vector3

Mirror(GameObject, float)

Creates or updates a mirrored copy of this airfoil on the target GameObject.

Declaration

public void Mirror(GameObject target = null, float positionThreshold = 0.02)

Parameters

Type	Name	Description
GameObject	target	GameObject to receive the mirrored airfoil. If null, automatically searches for a symmetric counterpart.
float	positionThreshold	Maximum position difference in meters to consider a GameObject as the mirror target.

Remarks

Mirrors the finite plane geometry, airfoil profile, and all settings to create a symmetric wing. If mirrorControlAirfoils is enabled, also mirrors all attached control surfaces. Useful for quickly setting up symmetric aircraft without manual duplication.

MirrorSlicingPoints(Airfoil, Airfoil)

Declaration

public static void MirrorSlicingPoints(Airfoil source, Airfoil target)

Parameters

Type	Name	Description
Airfoil	source
Airfoil	target

MirrorSlicingPointsFrom(Airfoil)

Copies and transforms slicing points from a source airfoil to this airfoil's local space.

Declaration

public void MirrorSlicingPointsFrom(Airfoil source)

Parameters

Type	Name	Description
Airfoil	source	Source airfoil whose slicing points will be copied.

Remarks

Used to ensure symmetric wings have matching section divisions. Only includes points that fall within this airfoil's span range. Automatically re-slices the airfoil after copying points.

OnDrawGizmosSelected()

Declaration

public void OnDrawGizmosSelected()

OrientateToMesh()

Aligns the airfoil's local coordinate system to match the best-fitting plane through the mesh vertices.

Declaration

public void OrientateToMesh()

Remarks

Uses principal component analysis to find the plane that best fits the mesh geometry. The airfoil's up vector is aligned to the mesh surface normal, ensuring proper lift direction. Requires a MeshFilter component on the parent GameObject.

ResetGeometry()

Declaration

public void ResetGeometry()

SetDefaults()

Sets airfoil defaults.

Declaration

public void SetDefaults()

Slice()

Divides the airfoil into spanwise sections at the generated slicing points.

Declaration

public void Slice()

Remarks

Creates AirfoilSection objects for each segment of the wing between slicing planes. Each section calculates its own area, chord length, and aerodynamic center. Also matches control surface sections to their corresponding main wing sections for coordinated simulation. Sections with area below 0.002 m² are discarded as too small for meaningful simulation.

See Also

AirfoilProfile

AirfoilSection

FinitePlane

AircraftController

ControlSurface