Defined in include/vehicle2/tire/PxVehicleTireFunctions.h

void PxVehicleTireStickyStateUpdate(const PxVehicleAxleDescription &axleDescription, const PxVehicleWheelParams &wheelParams, const PxVehicleTireStickyParams &tireStickyParams, const PxVehicleArrayData<const PxVehicleWheelActuationState> &actuationStates, const PxVehicleTireGripState &tireGripState, const PxVehicleTireSpeedState &tireSpeedState, const PxVehicleWheelRigidBody1dState &wheelRigidBody1dState, const PxReal dt, PxVehicleTireStickyState &tireStickyState)

When a tire has been at a very low speed for a threshold time without application of drive torque, a secondary tire model is applied to bring the tire to rest using velocity constraints that asymptotically approach zero speed along the tire’s lateral and longitudinal directions.

This secondary tire model is referred to as the sticky tire model and the tire is considered to be in the sticky tire state when the speed and time conditions are satisfied. The purpose of PxVehicleTireStickyStateUpdate is to compute the target speeds of the sticky state and to record whether sticky state is active or not.


The velocity constraints are maintained through integration with the PhysX scene using the function PxVehiclePhysXConstraintStatesUpdate. Alternative implementations independent of PhysX are possible.

  • axleDescription[in] is the axles of the vehicle and the wheels on each axle.

  • wheelParams[in] describes the radius of the wheel

  • tireStickyParams[in] describe the threshold speeds and times for the lateral and longitudinal sticky states.

  • actuationStates[in] describes whether each wheel experiences a drive torque.

  • tireGripState[in] is the load and friction experienced by the tire.

  • tireSpeedState[in] is the component of rigid body velocity at the tire contact point projected along the tire’s longitudinal and lateral axes.

  • wheelRigidBody1dState[in] is the wheel rotation speed.

  • dt[in] is the simulation time that has lapsed since the last call to PxVehicleTireStickyStateUpdate

  • tireStickyState[out] is a description of the sticky state of the tire in the longitudinal and lateral directions.