Defined in include/common/PxTolerancesScale.h

class PxTolerancesScale

Class to define the scale at which simulation runs.

Most simulation tolerances are calculated in terms of the values here.


if you change the simulation scale, you will probably also wish to change the scene’s default value of gravity, and stable simulation will probably require changes to the scene’s bounceThreshold also.

Public Functions

inline PxTolerancesScale(float defaultLength = 1.0f, float defaultSpeed = 10.0f)

constructor sets to default

  • defaultLength[in] Default length

  • defaultSpeed[in] Default speed

inline bool isValid() const

Returns true if the descriptor is valid.


true if the current settings are valid (returns always true).

Public Members

PxReal length

The approximate size of objects in the simulation.

For simulating roughly human-sized in metric units, 1 is a good choice. If simulation is done in centimetres, use 100 instead. This is used to estimate certain length-related tolerances.

PxReal speed

The typical magnitude of velocities of objects in simulation.

This is used to estimate whether a contact should be treated as bouncing or resting based on its impact velocity, and a kinetic energy threshold below which the simulation may put objects to sleep.

For normal physical environments, a good choice is the approximate speed of an object falling under gravity for one second.