physx::Px1DConstraint Struct Reference

A one-dimensional constraint. More...

#include <PxConstraintDesc.h>

Collaboration diagram for physx::Px1DConstraint:

Public Attributes
PxVec3	linear0
	linear component of velocity jacobian in world space
PxReal	geometricError
	geometric error of the constraint along this axis
PxVec3	angular0
	angular component of velocity jacobian in world space
PxReal	velocityTarget
	velocity target for the constraint along this axis
PxVec3	linear1
	linear component of velocity jacobian in world space
PxReal	minImpulse
	minimum impulse the solver may apply to enforce this constraint
PxVec3	angular1
	angular component of velocity jacobian in world space
PxReal	maxImpulse
	maximum impulse the solver may apply to enforce this constraint
union {
struct SpringModifiers {
PxReal   stiffness
	spring parameter, for spring constraints
PxReal   damping
	damping parameter, for spring constraints
}   spring
struct RestitutionModifiers {
PxReal   restitution
	restitution parameter for determining additional "bounce"
PxReal   velocityThreshold
	minimum impact velocity for bounce
}   bounce
}	mods
PxReal	forInternalUse
	for internal use only
PxU16	flags
	a set of Px1DConstraintFlags
PxU16	solveHint
	constraint optimization hint, should be an element of PxConstraintSolveHint

Detailed Description

A one-dimensional constraint.

A constraint is expressed as a set of 1-dimensional constraint rows which define the required constraint on the objects' velocities.

Each constraint is either a hard constraint or a spring. We define the velocity at the constraint to be the quantity

v = body0vel.dot(lin0,ang0) - body1vel.dot(lin1, ang1)

For a hard constraint, the solver attempts to generate

1. a set of velocities for the objects which, when integrated, respect the constraint errors:

   v + (geometricError / timestep) = velocityTarget

2. a set of velocities for the objects which respect the constraints:

   v = velocityTarget

Hard constraints support restitution: if the impact velocity exceeds the bounce threshold, then the target velocity of the constraint will be set to restitution * -v

Alternatively, the solver can attempt to resolve the velocity constraint as an implicit spring:

F = stiffness * -geometricError + damping * (velocityTarget - v)

where F is the constraint force or acceleration. Springs are fully implicit: that is, the force or acceleration is a function of the position and velocity after the solve.

All constraints support limits on the minimum or maximum impulse applied.

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

• RavEngine/deps/physx/physx/include/PxConstraintDesc.h