PxJointLinearLimitPair

Defined in include/extensions/PxJointLimit.h

class PxJointLinearLimitPair : public PxJointLimitParameters

Describes a two-sided limit.

Public Functions

inline PxJointLinearLimitPair(const PxTolerancesScale &scale, PxReal lowerLimit = -PX_MAX_F32 / 3.0f, PxReal upperLimit = PX_MAX_F32 / 3.0f)

Construct a linear hard limit pair.

The lower distance value must be less than the upper distance value.

See also

PxJointLimitParameters PxTolerancesScale

Parameters

  • scale – [in] A PxTolerancesScale struct. Should be the same as used when creating the PxPhysics object.

  • lowerLimit – [in] The lower distance of the limit

  • upperLimit – [in] The upper distance of the limit

inline PxJointLinearLimitPair(PxReal lowerLimit, PxReal upperLimit, const PxSpring &spring)

construct a linear soft limit pair

See also

PxJointLimitParameters

Parameters

  • lowerLimit – [in] The lower distance of the limit

  • upperLimit – [in] The upper distance of the limit

  • spring – [in] The stiffness and damping parameters of the limit spring

inline bool isValid() const

Returns true if the limit is valid.

Returns

true if the current settings are valid

inline bool isSoft() const

Public Members

PxReal upper

the range of the limit.

The upper limit must be no lower than the lower limit, and if they are equal the limited degree of freedom will be treated as locked.

Range: See the joint on which the limit is used for detailsDefault: lower = -PX_MAX_F32/3, upper = PX_MAX_F32/3

PxReal lower
PxReal restitution

Controls the amount of bounce when the joint hits a limit.

A restitution value of 1.0 causes the joint to bounce back with the velocity which it hit the limit. A value of zero causes the joint to stop dead.

In situations where the joint has many locked DOFs (e.g. 5) the restitution may not be applied correctly. This is due to a limitation in the solver which causes the restitution velocity to become zero as the solver enforces constraints on the other DOFs.

This limitation applies to both angular and linear limits, however it is generally most apparent with limited angular DOFs. Disabling joint projection and increasing the solver iteration count may improve this behavior to some extent.

Also, combining soft joint limits with joint drives driving against those limits may affect stability.

Range: [0,1]Default: 0.0

PxReal bounceThreshold

determines the minimum impact velocity which will cause the joint to bounce

PxReal stiffness

if greater than zero, the limit is soft, i.e.

a spring pulls the joint back to the limit

Range: [0, PX_MAX_F32)Default: 0.0

PxReal damping

if spring is greater than zero, this is the damping of the limit spring

Range: [0, PX_MAX_F32)Default: 0.0