MotionProperties Class Reference

The Body class only keeps track of state for static bodies, the MotionProperties class keeps the additional state needed for a moving Body. It has a 1-on-1 relationship with the body. More...

#include <MotionProperties.h>

Inheritance diagram for MotionProperties:

Public Member Functions
JPH_OVERRIDE_NEW_DELETE EMotionQuality	GetMotionQuality () const
	Motion quality, or how well it detects collisions when it has a high velocity.
EAllowedDOFs	GetAllowedDOFs () const
	Get the allowed degrees of freedom that this body has (this can be changed by calling SetMassProperties)
bool	GetAllowSleeping () const
	If this body can go to sleep.
Vec3	GetLinearVelocity () const
	Get world space linear velocity of the center of mass.
void	SetLinearVelocity (Vec3Arg inLinearVelocity)
	Set world space linear velocity of the center of mass.
void	SetLinearVelocityClamped (Vec3Arg inLinearVelocity)
	Set world space linear velocity of the center of mass, will make sure the value is clamped against the maximum linear velocity.
Vec3	GetAngularVelocity () const
	Get world space angular velocity of the center of mass.
void	SetAngularVelocity (Vec3Arg inAngularVelocity)
	Set world space angular velocity of the center of mass.
void	SetAngularVelocityClamped (Vec3Arg inAngularVelocity)
	Set world space angular velocity of the center of mass, will make sure the value is clamped against the maximum angular velocity.
void	MoveKinematic (Vec3Arg inDeltaPosition, QuatArg inDeltaRotation, float inDeltaTime)
	Set velocity of body such that it will be rotate/translate by inDeltaPosition/Rotation in inDeltaTime seconds.
void	ClampLinearVelocity ()
	Clamp velocity according to limit.
void	ClampAngularVelocity ()
float	GetLinearDamping () const
	Get linear damping: dv/dt = -c * v. c must be between 0 and 1 but is usually close to 0.
void	SetLinearDamping (float inLinearDamping)
float	GetAngularDamping () const
	Get angular damping: dw/dt = -c * w. c must be between 0 and 1 but is usually close to 0.
void	SetAngularDamping (float inAngularDamping)
float	GetGravityFactor () const
	Get gravity factor (1 = normal gravity, 0 = no gravity)
void	SetGravityFactor (float inGravityFactor)
void	SetMassProperties (EAllowedDOFs inAllowedDOFs, const MassProperties &inMassProperties)
	Set the mass and inertia tensor.
float	GetInverseMass () const
	Get inverse mass (1 / mass). Should only be called on a dynamic object (static or kinematic bodies have infinite mass so should be treated as 1 / mass = 0)
float	GetInverseMassUnchecked () const
void	SetInverseMass (float inInverseMass)
Vec3	GetInverseInertiaDiagonal () const
	Diagonal of inverse inertia matrix: D. Should only be called on a dynamic object (static or kinematic bodies have infinite mass so should be treated as D = 0)
Quat	GetInertiaRotation () const
	Rotation (R) that takes inverse inertia diagonal to local space: \(I_{body}^{-1} = R \: D \: R^{-1}\).
void	SetInverseInertia (Vec3Arg inDiagonal, QuatArg inRot)
Mat44	GetLocalSpaceInverseInertia () const
	Get inverse inertia matrix ( \(I_{body}^{-1}\)). Will be a matrix of zeros for a static or kinematic object.
Mat44	GetLocalSpaceInverseInertiaUnchecked () const
	Same as GetLocalSpaceInverseInertia() but doesn't check if the body is dynamic.
Mat44	GetInverseInertiaForRotation (Mat44Arg inRotation) const
	Get inverse inertia matrix ( \(I^{-1}\)) for a given object rotation (translation will be ignored). Zero if object is static or kinematic.
JPH_INLINE Vec3	MultiplyWorldSpaceInverseInertiaByVector (QuatArg inBodyRotation, Vec3Arg inV) const
	Multiply a vector with the inverse world space inertia tensor ( \(I_{world}^{-1}\)). Zero if object is static or kinematic.
JPH_INLINE Vec3	GetPointVelocityCOM (Vec3Arg inPointRelativeToCOM) const
	Velocity of point inPoint (in center of mass space, e.g. on the surface of the body) of the body (unit: m/s)
JPH_INLINE Vec3	GetAccumulatedForce () const
JPH_INLINE Vec3	GetAccumulatedTorque () const
JPH_INLINE void	ResetForce ()
JPH_INLINE void	ResetTorque ()
JPH_INLINE void	ResetMotion ()
JPH_INLINE UVec4	GetLinearDOFsMask () const
	Returns a vector where the linear components that are not allowed by mAllowedDOFs are set to 0 and the rest to 0xffffffff.
JPH_INLINE Vec3	LockTranslation (Vec3Arg inV) const
	Takes a translation vector inV and returns a vector where the components that are not allowed by mAllowedDOFs are set to 0.
JPH_INLINE UVec4	GetAngularDOFsMask () const
	Returns a vector where the angular components that are not allowed by mAllowedDOFs are set to 0 and the rest to 0xffffffff.
JPH_INLINE Vec3	LockAngular (Vec3Arg inV) const
	Takes an angular velocity / torque vector inV and returns a vector where the components that are not allowed by mAllowedDOFs are set to 0.
void	SetNumVelocityStepsOverride (uint inN)
	Used only when this body is dynamic and colliding. Override for the number of solver velocity iterations to run, 0 means use the default in PhysicsSettings::mNumVelocitySteps. The number of iterations to use is the max of all contacts and constraints in the island.
uint	GetNumVelocityStepsOverride () const
void	SetNumPositionStepsOverride (uint inN)
	Used only when this body is dynamic and colliding. Override for the number of solver position iterations to run, 0 means use the default in PhysicsSettings::mNumPositionSteps. The number of iterations to use is the max of all contacts and constraints in the island.
uint	GetNumPositionStepsOverride () const
void	ApplyGyroscopicForceInternal (QuatArg inBodyRotation, float inDeltaTime)
	Apply the gyroscopic force (aka Dzhanibekov effect, see https://en.wikipedia.org/wiki/Tennis_racket_theorem)
void	ApplyForceTorqueAndDragInternal (QuatArg inBodyRotation, Vec3Arg inGravity, float inDeltaTime)
	Apply all accumulated forces, torques and drag (should only be called by the PhysicsSystem)
uint32	GetIslandIndexInternal () const
	Access to the island index.
void	SetIslandIndexInternal (uint32 inIndex)
uint32	GetIndexInActiveBodiesInternal () const
	Access to the index in the active bodies array.
void	ResetSleepTestSpheres (const RVec3 *inPoints)
	Reset spheres to center around inPoints with radius 0.
void	ResetSleepTestTimer ()
	Reset the sleep test timer without resetting the sleep test spheres.
ECanSleep	AccumulateSleepTime (float inDeltaTime, float inTimeBeforeSleep)
	Accumulate sleep time and return if a body can go to sleep.
void	SaveState (StateRecorder &inStream) const
	Saving state for replay.
void	RestoreState (StateRecorder &inStream)
	Restoring state for replay.
Velocity limits
float	GetMaxLinearVelocity () const
	Maximum linear velocity that a body can achieve. Used to prevent the system from exploding.
void	SetMaxLinearVelocity (float inLinearVelocity)
float	GetMaxAngularVelocity () const
	Maximum angular velocity that a body can achieve. Used to prevent the system from exploding.
void	SetMaxAngularVelocity (float inAngularVelocity)
Update linear and angular velocity (used during constraint solving)
void	AddLinearVelocityStep (Vec3Arg inLinearVelocityChange)
void	SubLinearVelocityStep (Vec3Arg inLinearVelocityChange)
void	AddAngularVelocityStep (Vec3Arg inAngularVelocityChange)
void	SubAngularVelocityStep (Vec3Arg inAngularVelocityChange)

Static Public Attributes
static constexpr uint32	cInactiveIndex = uint32(-1)
	Constant indicating that body is not active.

Friends
class	BodyManager
class	Body

Detailed Description

The Body class only keeps track of state for static bodies, the MotionProperties class keeps the additional state needed for a moving Body. It has a 1-on-1 relationship with the body.

Member Function Documentation

AccumulateSleepTime()

ECanSleep MotionProperties::AccumulateSleepTime ( float  inDeltaTime, float  inTimeBeforeSleep  )

inline

Accumulate sleep time and return if a body can go to sleep.

AddAngularVelocityStep()

void MotionProperties::AddAngularVelocityStep ( Vec3Arg  inAngularVelocityChange )

inline

AddLinearVelocityStep()

void MotionProperties::AddLinearVelocityStep ( Vec3Arg  inLinearVelocityChange )

inline

ApplyForceTorqueAndDragInternal()

void MotionProperties::ApplyForceTorqueAndDragInternal ( QuatArg  inBodyRotation, Vec3Arg  inGravity, float  inDeltaTime  )

inline

Apply all accumulated forces, torques and drag (should only be called by the PhysicsSystem)

ApplyGyroscopicForceInternal()

void MotionProperties::ApplyGyroscopicForceInternal ( QuatArg  inBodyRotation, float  inDeltaTime  )

inline

Apply the gyroscopic force (aka Dzhanibekov effect, see https://en.wikipedia.org/wiki/Tennis_racket_theorem)

ClampAngularVelocity()

void MotionProperties::ClampAngularVelocity ( )

inline

ClampLinearVelocity()

void MotionProperties::ClampLinearVelocity ( )

inline

Clamp velocity according to limit.

GetAccumulatedForce()

JPH_INLINE Vec3 MotionProperties::GetAccumulatedForce ( ) const

inline

GetAccumulatedTorque()

JPH_INLINE Vec3 MotionProperties::GetAccumulatedTorque ( ) const

inline

GetAllowedDOFs()

EAllowedDOFs MotionProperties::GetAllowedDOFs ( ) const

inline

Get the allowed degrees of freedom that this body has (this can be changed by calling SetMassProperties)

GetAllowSleeping()

bool MotionProperties::GetAllowSleeping ( ) const

inline

If this body can go to sleep.

GetAngularDamping()

float MotionProperties::GetAngularDamping ( ) const

inline

Get angular damping: dw/dt = -c * w. c must be between 0 and 1 but is usually close to 0.

GetAngularDOFsMask()

JPH_INLINE UVec4 MotionProperties::GetAngularDOFsMask ( ) const

inline

Returns a vector where the angular components that are not allowed by mAllowedDOFs are set to 0 and the rest to 0xffffffff.

GetAngularVelocity()

Vec3 MotionProperties::GetAngularVelocity ( ) const

inline

Get world space angular velocity of the center of mass.

GetGravityFactor()

float MotionProperties::GetGravityFactor ( ) const

inline

Get gravity factor (1 = normal gravity, 0 = no gravity)

GetIndexInActiveBodiesInternal()

uint32 MotionProperties::GetIndexInActiveBodiesInternal ( ) const

inline

Access to the index in the active bodies array.

GetInertiaRotation()

Quat MotionProperties::GetInertiaRotation ( ) const

inline

Rotation (R) that takes inverse inertia diagonal to local space: \(I_{body}^{-1} = R \: D \: R^{-1}\).

GetInverseInertiaDiagonal()

Vec3 MotionProperties::GetInverseInertiaDiagonal ( ) const

inline

Diagonal of inverse inertia matrix: D. Should only be called on a dynamic object (static or kinematic bodies have infinite mass so should be treated as D = 0)

GetInverseInertiaForRotation()

Mat44 MotionProperties::GetInverseInertiaForRotation ( Mat44Arg  inRotation ) const

inline

Get inverse inertia matrix ( \(I^{-1}\)) for a given object rotation (translation will be ignored). Zero if object is static or kinematic.

GetInverseMass()

float MotionProperties::GetInverseMass ( ) const

inline

Get inverse mass (1 / mass). Should only be called on a dynamic object (static or kinematic bodies have infinite mass so should be treated as 1 / mass = 0)

GetInverseMassUnchecked()

float MotionProperties::GetInverseMassUnchecked ( ) const

inline

GetIslandIndexInternal()

uint32 MotionProperties::GetIslandIndexInternal ( ) const

inline

Access to the island index.

GetLinearDamping()

float MotionProperties::GetLinearDamping ( ) const

inline

Get linear damping: dv/dt = -c * v. c must be between 0 and 1 but is usually close to 0.

GetLinearDOFsMask()

JPH_INLINE UVec4 MotionProperties::GetLinearDOFsMask ( ) const

inline

Returns a vector where the linear components that are not allowed by mAllowedDOFs are set to 0 and the rest to 0xffffffff.

GetLinearVelocity()

Vec3 MotionProperties::GetLinearVelocity ( ) const

inline

Get world space linear velocity of the center of mass.

GetLocalSpaceInverseInertia()

Mat44 MotionProperties::GetLocalSpaceInverseInertia ( ) const

inline

Get inverse inertia matrix ( \(I_{body}^{-1}\)). Will be a matrix of zeros for a static or kinematic object.

GetLocalSpaceInverseInertiaUnchecked()

Mat44 MotionProperties::GetLocalSpaceInverseInertiaUnchecked ( ) const

inline

Same as GetLocalSpaceInverseInertia() but doesn't check if the body is dynamic.

GetMaxAngularVelocity()

float MotionProperties::GetMaxAngularVelocity ( ) const

inline

Maximum angular velocity that a body can achieve. Used to prevent the system from exploding.

GetMaxLinearVelocity()

float MotionProperties::GetMaxLinearVelocity ( ) const

inline

Maximum linear velocity that a body can achieve. Used to prevent the system from exploding.

GetMotionQuality()

JPH_OVERRIDE_NEW_DELETE EMotionQuality MotionProperties::GetMotionQuality ( ) const

inline

Motion quality, or how well it detects collisions when it has a high velocity.

GetNumPositionStepsOverride()

uint MotionProperties::GetNumPositionStepsOverride ( ) const

inline

GetNumVelocityStepsOverride()

uint MotionProperties::GetNumVelocityStepsOverride ( ) const

inline

GetPointVelocityCOM()

JPH_INLINE Vec3 MotionProperties::GetPointVelocityCOM ( Vec3Arg  inPointRelativeToCOM ) const

inline

Velocity of point inPoint (in center of mass space, e.g. on the surface of the body) of the body (unit: m/s)

LockAngular()

JPH_INLINE Vec3 MotionProperties::LockAngular ( Vec3Arg  inV ) const

inline

Takes an angular velocity / torque vector inV and returns a vector where the components that are not allowed by mAllowedDOFs are set to 0.

LockTranslation()

JPH_INLINE Vec3 MotionProperties::LockTranslation ( Vec3Arg  inV ) const

inline

Takes a translation vector inV and returns a vector where the components that are not allowed by mAllowedDOFs are set to 0.

MoveKinematic()

JPH_NAMESPACE_BEGIN void MotionProperties::MoveKinematic ( Vec3Arg  inDeltaPosition, QuatArg  inDeltaRotation, float  inDeltaTime  )

inline

Set velocity of body such that it will be rotate/translate by inDeltaPosition/Rotation in inDeltaTime seconds.

MultiplyWorldSpaceInverseInertiaByVector()

Vec3 MotionProperties::MultiplyWorldSpaceInverseInertiaByVector	(	QuatArg	inBodyRotation,
		Vec3Arg	inV
	)		const

Multiply a vector with the inverse world space inertia tensor ( \(I_{world}^{-1}\)). Zero if object is static or kinematic.

ResetForce()

JPH_INLINE void MotionProperties::ResetForce ( )

inline

ResetMotion()

JPH_INLINE void MotionProperties::ResetMotion ( )

inline

ResetSleepTestSpheres()

void MotionProperties::ResetSleepTestSpheres ( const RVec3 *  inPoints )

inline

Reset spheres to center around inPoints with radius 0.

ResetSleepTestTimer()

void MotionProperties::ResetSleepTestTimer ( )

inline

Reset the sleep test timer without resetting the sleep test spheres.

ResetTorque()

JPH_INLINE void MotionProperties::ResetTorque ( )

inline

RestoreState()

void MotionProperties::RestoreState

(

StateRecorder &

inStream

)

Restoring state for replay.

SaveState()

void MotionProperties::SaveState

(

StateRecorder &

inStream

)

const

Saving state for replay.

SetAngularDamping()

void MotionProperties::SetAngularDamping ( float  inAngularDamping )

inline

SetAngularVelocity()

void MotionProperties::SetAngularVelocity ( Vec3Arg  inAngularVelocity )

inline

Set world space angular velocity of the center of mass.

SetAngularVelocityClamped()

void MotionProperties::SetAngularVelocityClamped ( Vec3Arg  inAngularVelocity )

inline

Set world space angular velocity of the center of mass, will make sure the value is clamped against the maximum angular velocity.

SetGravityFactor()

void MotionProperties::SetGravityFactor ( float  inGravityFactor )

inline

SetInverseInertia()

void MotionProperties::SetInverseInertia ( Vec3Arg  inDiagonal, QuatArg  inRot  )

inline

Set the inverse inertia tensor in local space by setting the diagonal and the rotation: \(I_{body}^{-1} = R \: D \: R^{-1}\). Note that mass and inertia are linearly related (e.g. inertia of a sphere with mass m and radius r is \(2/5 \: m \: r^2\)). If you change inertia, mass should probably change as well. See MassProperties::ScaleToMass. If all your rotation degrees of freedom are restricted, make sure this is zero (see EAllowedDOFs).

SetInverseMass()

void MotionProperties::SetInverseMass ( float  inInverseMass )

inline

Set the inverse mass (1 / mass). Note that mass and inertia are linearly related (e.g. inertia of a sphere with mass m and radius r is \(2/5 \: m \: r^2\)). If you change mass, inertia should probably change as well. See MassProperties::ScaleToMass. If all your translation degrees of freedom are restricted, make sure this is zero (see EAllowedDOFs).

SetIslandIndexInternal()

void MotionProperties::SetIslandIndexInternal ( uint32  inIndex )

inline

SetLinearDamping()

void MotionProperties::SetLinearDamping ( float  inLinearDamping )

inline

SetLinearVelocity()

void MotionProperties::SetLinearVelocity ( Vec3Arg  inLinearVelocity )

inline

Set world space linear velocity of the center of mass.

SetLinearVelocityClamped()

void MotionProperties::SetLinearVelocityClamped ( Vec3Arg  inLinearVelocity )

inline

Set world space linear velocity of the center of mass, will make sure the value is clamped against the maximum linear velocity.

SetMassProperties()

JPH_NAMESPACE_BEGIN void MotionProperties::SetMassProperties	(	EAllowedDOFs	inAllowedDOFs,
		const MassProperties &	inMassProperties
	)

Set the mass and inertia tensor.

SetMaxAngularVelocity()

void MotionProperties::SetMaxAngularVelocity ( float  inAngularVelocity )

inline

SetMaxLinearVelocity()

void MotionProperties::SetMaxLinearVelocity ( float  inLinearVelocity )

inline

SetNumPositionStepsOverride()

void MotionProperties::SetNumPositionStepsOverride ( uint  inN )

inline

Used only when this body is dynamic and colliding. Override for the number of solver position iterations to run, 0 means use the default in PhysicsSettings::mNumPositionSteps. The number of iterations to use is the max of all contacts and constraints in the island.

SetNumVelocityStepsOverride()

void MotionProperties::SetNumVelocityStepsOverride ( uint  inN )

inline

Used only when this body is dynamic and colliding. Override for the number of solver velocity iterations to run, 0 means use the default in PhysicsSettings::mNumVelocitySteps. The number of iterations to use is the max of all contacts and constraints in the island.

SubAngularVelocityStep()

void MotionProperties::SubAngularVelocityStep ( Vec3Arg  inAngularVelocityChange )

inline

SubLinearVelocityStep()

void MotionProperties::SubLinearVelocityStep ( Vec3Arg  inLinearVelocityChange )

inline

Friends And Related Symbol Documentation

Body

friend class Body

friend

BodyManager

friend class BodyManager

friend

Member Data Documentation

cInactiveIndex

constexpr uint32 MotionProperties::cInactiveIndex = uint32(-1)

staticconstexpr

Constant indicating that body is not active.

---

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

• Jolt/Physics/Body/MotionProperties.h
• Jolt/Physics/Body/MotionProperties.cpp
• Jolt/Physics/Body/MotionProperties.inl