physx::PxVehicleSuspensionData Class Reference

Public Member Functions
PX_FORCE_INLINE PxReal	getRecipMaxCompression () const
	Reciprocal of maximum compression.
PX_FORCE_INLINE PxReal	getRecipMaxDroop () const
	Reciprocal of maximum droop.
void	setMassAndPreserveNaturalFrequency (const PxReal newSprungMass)
	Set a new sprung mass for the suspension and modify the spring strength so that the natural frequency of the spring is preserved.

Public Attributes
PxReal	mSpringStrength
	Spring strength of suspension unit.
PxReal	mSpringDamperRate
	Spring damper rate of suspension unit.
PxReal	mMaxCompression
	Maximum compression allowed by suspension spring.
PxReal	mMaxDroop
	Maximum elongation allowed by suspension spring.
PxReal	mSprungMass
	Mass of vehicle that is supported by suspension spring.
PxReal	mCamberAtRest
	Camber angle (in radians) of wheel when the suspension is at its rest position.
PxReal	mCamberAtMaxCompression
	Camber angle (in radians) of wheel when the suspension is at maximum compression.
PxReal	mCamberAtMaxDroop
	Camber angle (in radians) of wheel when the suspension is at maximum droop.

Friends
class	PxVehicleWheels4SimData

Member Function Documentation

getRecipMaxCompression()

PX_FORCE_INLINE PxReal physx::PxVehicleSuspensionData::getRecipMaxCompression ( ) const

inline

Reciprocal of maximum compression.

Note

Not necessary to set this value because it is set by PxVehicleWheelsSimData::setSuspensionData

Range: [0, PX_MAX_F32)

getRecipMaxDroop()

PX_FORCE_INLINE PxReal physx::PxVehicleSuspensionData::getRecipMaxDroop ( ) const

inline

Reciprocal of maximum droop.

Note

Not necessary to set this value because it is set by PxVehicleWheelsSimData::setSuspensionData

Range: [0, PX_MAX_F32)

setMassAndPreserveNaturalFrequency()

void physx::PxVehicleSuspensionData::setMassAndPreserveNaturalFrequency ( const PxReal  newSprungMass )

inline

Set a new sprung mass for the suspension and modify the spring strength so that the natural frequency of the spring is preserved.

Parameters

[in]

newSprungMass

is the new mass that the suspension spring will support.

Member Data Documentation

mCamberAtMaxCompression

PxReal physx::PxVehicleSuspensionData::mCamberAtMaxCompression

Camber angle (in radians) of wheel when the suspension is at maximum compression.

Note

For compressed suspensions the camber angle is a linear interpolation of mCamberAngleAtRest and mCamberAtMaxCompression

Specified in radians.

Range: [-pi/2, pi/2]

mCamberAtMaxDroop

PxReal physx::PxVehicleSuspensionData::mCamberAtMaxDroop

Camber angle (in radians) of wheel when the suspension is at maximum droop.

Note

For extended suspensions the camber angle is linearly interpolation of mCamberAngleAtRest and mCamberAtMaxDroop

Specified in radians.

Range: [-pi/2, pi/2]

mCamberAtRest

PxReal physx::PxVehicleSuspensionData::mCamberAtRest

Camber angle (in radians) of wheel when the suspension is at its rest position.

Note

Specified in radians.

Range: [-pi/2, pi/2]

mMaxCompression

PxReal physx::PxVehicleSuspensionData::mMaxCompression

Maximum compression allowed by suspension spring.

Note

Specified in metres (m).

Range: [0, PX_MAX_F32)

mMaxDroop

PxReal physx::PxVehicleSuspensionData::mMaxDroop

Maximum elongation allowed by suspension spring.

Note

Specified in metres (m).

Range: [0, PX_MAX_F32)

mSpringDamperRate

PxReal physx::PxVehicleSuspensionData::mSpringDamperRate

Spring damper rate of suspension unit.

Note

Specified in kilograms per second (kg s^-1).

Range: [0, PX_MAX_F32)

mSpringStrength

PxReal physx::PxVehicleSuspensionData::mSpringStrength

Spring strength of suspension unit.

Note

Specified in kilograms per second-squared (kg s^-2).

Range: [0, PX_MAX_F32)

mSprungMass

PxReal physx::PxVehicleSuspensionData::mSprungMass

Mass of vehicle that is supported by suspension spring.

Note

Specified in kilograms (kg).

Each suspension is guaranteed to generate an upwards force of |gravity|*mSprungMass along the suspension direction when the wheel is perfectly at rest and sitting at the rest pose defined by the wheel centre offset.

The sum of the sprung masses of all suspensions of a vehicle should match the mass of the PxRigidDynamic associated with the vehicle.
When this condition is satisfied for a vehicle on a horizontal plane the wheels of the vehicle are guaranteed to sit at the rest pose defined by the wheel centre offset. For special cases, where this condition can not be met easily, the flag PxVehicleWheelsSimFlag::eDISABLE_SPRUNG_MASS_SUM_CHECK allows to provide sprung mass values that do not sum up to the mass of the PxRigidDynamic.

As the wheel compresses or elongates along the suspension direction the force generated by the spring is F = |gravity|*mSprungMass + deltaX*mSpringStrength + deltaXDot*mSpringDamperRate where deltaX is the deviation from the defined rest pose and deltaXDot is the velocity of the sprung mass along the suspension direction. In practice, deltaXDot is computed by comparing the current and previous deviation from the rest pose and dividing the difference by the simulation timestep.

If a single suspension spring is hanging in the air and generates zero force the remaining springs of the vehicle will necessarily sit in a compressed configuration. In summary, the sum of the remaining suspension forces cannot balance the downwards gravitational force acting on the vehicle without extra force arising from the deltaX*mSpringStrength force term.

Theoretically, a suspension spring should generate zero force at maximum elongation and increase linearly as the suspension approaches the rest pose. PxVehicleSuspensionData will only enforce this physical law if the spring is configured so that |gravity|*mSprungMass == mMaxDroop*mSpringStrength.
To help decouple vehicle handling from visual wheel positioning this condition is not enforced.
In practice, the value of |gravity|*mSprungMass + deltaX*mSpringStrength is clamped at zero to ensure it never falls negative.

See also

PxVehicleComputeSprungMasses, PxVehicleWheelsSimData::setWheelCentreOffset, PxVehicleSuspensionData::mSpringStrength, PxVehicleSuspensionData::mSpringDamperRate, PxVehicleSuspensionData::mMaxDroop

Range: [0, PX_MAX_F32)

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The documentation for this class was generated from the following files:

• RavEngine/deps/physx/physx/include/vehicle/PxVehicleComponents.h
• RavEngine/deps/physx/physx/source/physxvehicle/src/PxVehicleComponents.cpp