physx::vehicle2::PxVehicleTireAxisStickyParams Struct Reference

The low speed regime often presents numerical difficulties for the tire model due to the potential for divide-by-zero errors. This particularly affects scenarios where the vehicle is slowing down due to damping and drag. In scenarios where there is no significant brake or drive torque, numerical error begins to dominate and it can be difficult to bring the vehicle to rest. A solution to this problem is to recognise that the vehicle is close to rest and to replace the tire forces with velocity constraints that will bring the vehicle to rest. This regime is known as the "sticky tire" regime. PxVehicleTireAxisStickyParams describes velocity and time thresholds that categorise the "sticky tire" regime. It also describes the rate at which the velocity constraints approach zero speed. More...

#include <PxVehicleParams.h>

Public Member Functions
PX_FORCE_INLINE PxVehicleTireAxisStickyParams	transformAndScale (const PxVehicleFrame &srcFrame, const PxVehicleFrame &trgFrame, const PxVehicleScale &srcScale, const PxVehicleScale &trgScale) const
PX_FORCE_INLINE bool	isValid () const

Public Attributes
PxReal	thresholdSpeed
	A tire enters the "sticky tire" regime when it has been below a speed specified by thresholdSpeed for a continuous time specified by thresholdTime.
PxReal	thresholdTime
	A tire enters the "sticky tire" regime when it has been below a speed specified by thresholdSpeed for a continuous time specified by thresholdTime.
PxReal	damping
	The rate at which the velocity constraint approaches zero is controlled by the damping parameter.

Detailed Description

The low speed regime often presents numerical difficulties for the tire model due to the potential for divide-by-zero errors. This particularly affects scenarios where the vehicle is slowing down due to damping and drag. In scenarios where there is no significant brake or drive torque, numerical error begins to dominate and it can be difficult to bring the vehicle to rest. A solution to this problem is to recognise that the vehicle is close to rest and to replace the tire forces with velocity constraints that will bring the vehicle to rest. This regime is known as the "sticky tire" regime. PxVehicleTireAxisStickyParams describes velocity and time thresholds that categorise the "sticky tire" regime. It also describes the rate at which the velocity constraints approach zero speed.

Member Data Documentation

damping

PxReal physx::vehicle2::PxVehicleTireAxisStickyParams::damping

The rate at which the velocity constraint approaches zero is controlled by the damping parameter.

Note

Larger values of damping lead to faster approaches to zero. Since the damping behaves like a stiffness with respect to the velocity, too large a value can lead to instabilities.

Range: [0, inf)
Unit: 1 / time (acceleration instead of force based damping, thus not mass/time)

thresholdSpeed

PxReal physx::vehicle2::PxVehicleTireAxisStickyParams::thresholdSpeed

A tire enters the "sticky tire" regime when it has been below a speed specified by thresholdSpeed for a continuous time specified by thresholdTime.

Range: [0, inf)
Unit: velocity = length / time

thresholdTime

PxReal physx::vehicle2::PxVehicleTireAxisStickyParams::thresholdTime

A tire enters the "sticky tire" regime when it has been below a speed specified by thresholdSpeed for a continuous time specified by thresholdTime.

Range: [0, inf)
Unit: time

---

The documentation for this struct was generated from the following file:

• RavEngine/deps/physx/physx/include/vehicle2/PxVehicleParams.h