#include <PxConstraintDesc.h>
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 | |
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.
angular component of velocity jacobian in world space
angular component of velocity jacobian in world space
| struct { ... } ::RestitutionModifiers Px1DConstraint::bounce |
| PxReal Px1DConstraint::damping |
damping parameter, for spring constraints
| PxU16 Px1DConstraint::flags |
a set of Px1DConstraintFlags
for internal use only
geometric error of the constraint along this axis
linear component of velocity jacobian in world space
linear component of velocity jacobian in world space
| PxReal Px1DConstraint::maxImpulse |
maximum impulse the solver may apply to enforce this constraint
| PxReal Px1DConstraint::minImpulse |
minimum impulse the solver may apply to enforce this constraint
| union { ... } Px1DConstraint::mods |
| PxReal Px1DConstraint::restitution |
restitution parameter for determining additional "bounce"
constraint optimization hint, should be an element of PxConstraintSolveHint
| struct { ... } ::SpringModifiers Px1DConstraint::spring |
| PxReal Px1DConstraint::stiffness |
spring parameter, for spring constraints
velocity target for the constraint along this axis
minimum impact velocity for bounce