Defined in include/PxArticulationReducedCoordinate.h

class PxArticulationCache

Data structure used to read and write internal articulation data.

Public Functions

inline PxArticulationCache()
void release()

Releases an articulation cache.

Public Members

PxSpatialForce *externalForces

External forces acting on the articulation links for inverse dynamics computation.

  • N = getNbLinks().

  • Indexing follows the low-level link indices, see PxArticulationLink::getLinkIndex.

  • The forces are with respect to the center of mass of the link.

PxReal *denseJacobian

Dense Jacobian data.

PxReal *massMatrix

The generalized mass matrix that maps joint accelerations to joint forces.

PxReal *jointVelocity

The articulation joint DOF velocities.

  • N = getDofs().

  • Read/write using PxArticulationCacheFlag::eVELOCITY.

  • The indexing follows the internal DOF index order. Therefore, the application should calculate the DOF data indices by summing the joint DOFs in the order of the links’ low-level indices (see the manual Section “Cache Indexing” for a snippet for this calculation):

    Low-level link index:   | link 0 | link 1 | link 2 | link 3 | ... | <- PxArticulationLink::getLinkIndex()
    Link inbound joint DOF: | 0      | 1      | 2      | 1      | ... | <- PxArticulationLink::getInboundJointDof()
    Low-level DOF index:    | -      | 0      | 1, 2   | 3      | ... |
    The root link always has low-level index 0 and always has zero inbound joint DOFs. The link DOF indexing follows the order in PxArticulationAxis::Enum. For example, assume that low-level link 2 has an inbound spherical joint with two DOFs: eSWING1 and eSWING2. The corresponding low-level joint DOF indices are therefore 1 for eSWING1 and 2 for eSWING2.

PxReal *jointAcceleration

The articulation joint DOF accelerations.

PxReal *jointPosition

The articulation joint DOF positions.

PxReal *jointForce

The articulation joint DOF forces.

PxReal *jointSolverForces

Solver constraint joint DOF forces.

PxSpatialVelocity *linkVelocity

Link spatial velocity.

PxSpatialVelocity *linkAcceleration

Link classical acceleration.

PxArticulationRootLinkData *rootLinkData

Root link transform, velocities, and accelerations.

PxSpatialForce *sensorForces

Link sensor spatial forces.

PxReal *coefficientMatrix

Constraint coefficient matrix.

  • N = getCoefficentMatrixSize().

  • The user needs to allocate memory and set this member to the allocated memory.

PxReal *lambda

Constraint lambda values (impulses applied by the respective constraints).

  • N = getNbLoopJoints().

  • The user needs to allocate memory and set this member to the allocated memory.

void *scratchMemory

The scratch memory is used for internal calculations.

void *scratchAllocator

The scratch allocator is used for internal calculations.

PxU32 version

The cache version used internally to check compatibility with the articulation, i.e. detect if the articulation configuration changed after the cache was created.