PxMassProperties Class Reference
[Extensions]

Utility class to compute and manipulate mass and inertia tensor properties. More...

#include <PxMassProperties.h>

Collaboration diagram for PxMassProperties:

[legend]

List of all members.

Public Member Functions
PX_FORCE_INLINE	PxMassProperties ()
	Default constructor.
PX_FORCE_INLINE	PxMassProperties (const PxReal m, const PxMat33 &inertiaT, const PxVec3 &com)
	Construct from individual elements.
	PxMassProperties (const PxGeometry &geometry)
	Compute mass properties based on a provided geometry structure.
PX_FORCE_INLINE PxMassProperties	operator* (const PxReal scale) const
	Scale mass properties.
PX_FORCE_INLINE void	translate (const PxVec3 &t)
	Translate the center of mass by a given vector and adjust the inertia tensor accordingly.
Static Public Member Functions
static PX_FORCE_INLINE PxVec3	getMassSpaceInertia (const PxMat33 &inertia, PxQuat &massFrame)
	Get the entries of the diagonalized inertia tensor and the corresponding reference rotation.
static PX_FORCE_INLINE PxMat33	translateInertia (const PxMat33 &inertia, const PxReal mass, const PxVec3 &t)
	Translate an inertia tensor using the parallel axis theorem.
static PX_FORCE_INLINE PxMat33	rotateInertia (const PxMat33 &inertia, const PxQuat &q)
	Rotate an inertia tensor around the center of mass.
static PxMat33	scaleInertia (const PxMat33 &inertia, const PxQuat &scaleRotation, const PxVec3 &scale)
	Non-uniform scaling of the inertia tensor.
static PxMassProperties	sum (const PxMassProperties *props, const PxTransform *transforms, const PxU32 count)
	Sum up individual mass properties.
Public Attributes
PxMat33	inertiaTensor
	The inertia tensor of the object.
PxVec3	centerOfMass
	The center of mass of the object.
PxReal	mass
	The mass of the object.

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Detailed Description

Utility class to compute and manipulate mass and inertia tensor properties.

In most cases PxRigidBodyExt::updateMassAndInertia(), PxRigidBodyExt::setMassAndUpdateInertia() should be enough to setup the mass properties of a rigid body. This utility class targets users that need to customize the mass properties computation.

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Constructor & Destructor Documentation

PX_FORCE_INLINE PxMassProperties::PxMassProperties

(

)

[inline]

Default constructor.

PX_FORCE_INLINE PxMassProperties::PxMassProperties	(	const PxReal	m,
		const PxMat33 &	inertiaT,
		const PxVec3 &	com
	)			[inline]

Construct from individual elements.

PxMassProperties::PxMassProperties

(

const PxGeometry &

geometry

)

[inline]

Compute mass properties based on a provided geometry structure.

This constructor assumes the geometry has a density of 1. Mass and inertia tensor scale linearly with density.

Parameters:

[in]

geometry

The geometry to compute the mass properties for. Supported geometry types are: sphere, box, capsule and convex mesh.

References PxConvexMeshGeometry::convexMesh, PxMat33::createDiagonal(), PxGeometryType::eBOX, PxGeometryType::eCAPSULE, PxGeometryType::eCONVEXMESH, PxGeometryType::eGEOMETRY_COUNT, PxGeometryType::eHEIGHTFIELD, PxGeometryType::eINVALID, PxGeometryType::ePLANE, PxGeometryType::eSPHERE, PxGeometryType::eTRIANGLEMESH, PxConvexMesh::getMassInformation(), PxGeometry::getType(), PxBoxGeometry::halfExtents, PxCapsuleGeometry::halfHeight, PxVec3::multiply(), PX_ASSERT, PxIsFinite(), PxPi, PxCapsuleGeometry::radius, PxSphereGeometry::radius, PxQuat::rotate(), PxQuat::rotateInv(), PxMeshScale::rotation, PxMeshScale::scale, PxConvexMeshGeometry::scale, PxVec3::x, PxVec3::y, and PxVec3::z.

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Member Function Documentation

static PX_FORCE_INLINE PxVec3 PxMassProperties::getMassSpaceInertia	(	const PxMat33 &	inertia,
		PxQuat &	massFrame
	)			[inline, static]

Get the entries of the diagonalized inertia tensor and the corresponding reference rotation.

Parameters:

[in]	inertia	The inertia tensor to diagonalize.
[out]	massFrame	The frame the diagonalized tensor refers to.

Returns:

The entries of the diagonalized inertia tensor.

References PxMat33::column0, PxMat33::column1, PxMat33::column2, PxQuat::isFinite(), PxVec3::isFinite(), PX_ASSERT, and PxDiagonalize().

PX_FORCE_INLINE PxMassProperties PxMassProperties::operator*

(

const PxReal

scale

)

const [inline]

Scale mass properties.

Parameters:

[in]

scale

The linear scaling factor to apply to the mass properties.

Returns:

The scaled mass properties.

References PX_ASSERT, and PxIsFinite().

static PX_FORCE_INLINE PxMat33 PxMassProperties::rotateInertia	(	const PxMat33 &	inertia,
		const PxQuat &	q
	)			[inline, static]

Rotate an inertia tensor around the center of mass.

Parameters:

[in]	inertia	The inertia tensor to rotate.
[in]	q	The rotation to apply to the inertia tensor.

Returns:

The rotated inertia tensor.

References PxMat33::column0, PxMat33::column1, PxMat33::column2, PxMat33::getTranspose(), PxVec3::isFinite(), PxQuat::isUnit(), and PX_ASSERT.

static PxMat33 PxMassProperties::scaleInertia	(	const PxMat33 &	inertia,
		const PxQuat &	scaleRotation,
		const PxVec3 &	scale
	)			[inline, static]

Non-uniform scaling of the inertia tensor.

Parameters:

[in]	inertia	The inertia tensor to scale.
[in]	scaleRotation	The frame of the provided scaling factors.
[in]	scale	The scaling factor for each axis (relative to the frame specified in scaleRotation).

Returns:

The scaled inertia tensor.

References PxMat33::column0, PxMat33::column1, PxMat33::column2, PxVec3::dot(), PxQuat::getConjugate(), PxVec3::isFinite(), PxQuat::isUnit(), PxVec3::multiply(), PX_ASSERT, PxVec3::x, PxVec3::y, and PxVec3::z.

static PxMassProperties PxMassProperties::sum	(	const PxMassProperties *	props,
		const PxTransform *	transforms,
		const PxU32	count
	)			[inline, static]

Sum up individual mass properties.

Parameters:

[in]	props	Array of mass properties to sum up.
[in]	transforms	Reference transforms for each mass properties entry.
[in]	count	The number of mass properties to sum up.

Returns:

The summed up mass properties.

References PxMat33::column0, PxMat33::column1, PxMat33::column2, inertiaTensor, PxVec3::isFinite(), mass, PX_ASSERT, PxIsFinite(), PxZero, and PxTransform::transform().

PX_FORCE_INLINE void PxMassProperties::translate

(

const PxVec3 &

t

)

[inline]

Translate the center of mass by a given vector and adjust the inertia tensor accordingly.

Parameters:

[in]

t

The translation vector for the center of mass.

References PxVec3::isFinite(), and PX_ASSERT.

static PX_FORCE_INLINE PxMat33 PxMassProperties::translateInertia	(	const PxMat33 &	inertia,
		const PxReal	mass,
		const PxVec3 &	t
	)			[inline, static]

Translate an inertia tensor using the parallel axis theorem.

Parameters:

[in]	inertia	The inertia tensor to translate.
[in]	mass	The mass of the object.
[in]	t	The relative frame to translate the inertia tensor to.

Returns:

The translated inertia tensor.

References PxMat33::column0, PxMat33::column1, PxMat33::column2, PxVec3::isFinite(), PX_ASSERT, PxIsFinite(), PxVec3::x, PxVec3::y, and PxVec3::z.

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Member Data Documentation

PxVec3 PxMassProperties::centerOfMass

The center of mass of the object.

PxMat33 PxMassProperties::inertiaTensor

The inertia tensor of the object.

Referenced by sum().

PxReal PxMassProperties::mass

The mass of the object.

Referenced by sum().

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

• PxMassProperties.h