#include <MPxConstraint.h>

Class Description

Proxy constraint node.

MPxConstraint is the parent class for user defined constraint nodes. Position, orientation or scale of an object can be constrained by other objects. This class works in conjunction with the MPxConstraintCommand class.

Examples:: geometrySurfaceConstraint/geometrySurfaceConstraint.cpp, and geometrySurfaceConstraint/geometrySurfaceConstraint.h.

Inheritance diagram for MPxConstraint:

Public Types
enum	UpVectorType { kScene = 0, kObject, kObjectRotation, kVector, kLast }
	The type of up vector. More...

Public Types inherited from MPxNode
enum	Type { kDependNode, kLocatorNode, kDeformerNode, kManipContainer, kSurfaceShape, kFieldNode, kEmitterNode, kSpringNode, kIkSolverNode, kHardwareShader, kHwShaderNode, kTransformNode, kObjectSet, kFluidEmitterNode, kImagePlaneNode, kParticleAttributeMapperNode, kCameraSetNode, kConstraintNode, kManipulatorNode, kMotionPathNode, kClientDeviceNode, kThreadedDeviceNode, kAssembly, kSkinCluster, kGeometryFilter, kBlendShape, kLast }
	Defines the type of node. More...

enum	SchedulingType { kParallel, kSerial, kGloballySerial, kUntrusted, kDefaultScheduling = kSerial }
	Defines the degree of parallelism of a node. More...

Public Member Functions
	MPxConstraint ()
	Constructor. More...

virtual	~MPxConstraint ()
	Destructor.

virtual const MObject	weightAttribute () const
	Returns the weight attribute for the constraint. More...

virtual const MObject	targetAttribute () const
	Returns the target attribute for the constraint. More...

virtual const MObject	constraintRotateOrderAttribute () const
	Returns the rotate order attribute for the constraint. More...

Public Member Functions inherited from MPxNode
	MPxNode ()
	Constructor. More...

virtual	~MPxNode ()
	Destructor.

virtual void	postConstructor ()
	Post constructor. More...

virtual MStatus	compute (const MPlug &plug, MDataBlock &dataBlock)
	This method should be overridden in user defined nodes. More...

virtual bool	getInternalValueInContext (const MPlug &plug, MDataHandle &dataHandle, MDGContext &ctx)
	This method is overridden by nodes that store attribute data in some internal format. More...

virtual bool	setInternalValueInContext (const MPlug &plug, const MDataHandle &dataHandle, MDGContext &ctx)
	This method is overridden by nodes that store attribute data in some internal format. More...

virtual bool	getInternalValue (const MPlug &plug, MDataHandle &dataHandle)
	This method is obsolete. More...

virtual bool	setInternalValue (const MPlug &plug, const MDataHandle &dataHandle)
	This method is obsolete. More...

virtual int	internalArrayCount (const MPlug &plug, const MDGContext &ctx) const
	This method is overridden by nodes that have internal array attributes which are not stored in Maya's datablock. More...

virtual void	copyInternalData (MPxNode *)
	This method is overridden by nodes that store attribute data in some internal format. More...

virtual MStatus	legalConnection (const MPlug &plug, const MPlug &otherPlug, bool asSrc, bool &isLegal) const
	This method allows you to check for legal connections being made to attributes of this node. More...

virtual MStatus	legalDisconnection (const MPlug &plug, const MPlug &otherPlug, bool asSrc, bool &isLegal) const
	This method allows you to check for legal disconnections being made to attributes of this node. More...

virtual MStatus	setDependentsDirty (const MPlug &plug, MPlugArray &plugArray)
	This method can be overridden in user defined nodes to specify which plugs should be set dirty based upon an input plug {plugBeingDirtied} which Maya is marking dirty. More...

virtual MStatus	preEvaluation (const MDGContext &context, const MEvaluationNode &evaluationNode)
	Prepare a node's internal state for threaded evaluation. More...

virtual MStatus	postEvaluation (const MDGContext &context, const MEvaluationNode &evaluationNode, PostEvaluationType evalType)
	Clean up node's internal state after threaded evaluation. More...

virtual SchedulingType	schedulingType () const
	When overridden this method controls the degree of parallelism supported by the node during threaded evaluation. More...

virtual MStatus	connectionMade (const MPlug &plug, const MPlug &otherPlug, bool asSrc)
	This method gets called when connections are made to attributes of this node. More...

virtual MStatus	connectionBroken (const MPlug &plug, const MPlug &otherPlug, bool asSrc)
	This method gets called when connections are broken with attributes of this node. More...

virtual MStatus	dependsOn (const MPlug &plug, const MPlug &otherPlug, bool &depends) const
	This method may be overridden by the user defined node. More...

virtual bool	isPassiveOutput (const MPlug &plug) const
	This method may be overridden by the user defined node if it wants to provide output attributes which do not prevent value modifications to the destination attribute. More...

virtual MStatus	shouldSave (const MPlug &plug, bool &isSaving)
	This method may be overridden by the user defined node. More...

virtual MPlug	passThroughToOne (const MPlug &plug) const
	This method may be overridden by nodes that have a one-to-one relationship between an input attribute and a corresponding output attribute. More...

virtual bool	passThroughToMany (const MPlug &plug, MPlugArray &plugArray) const
	This method is overridden by nodes that want to control the traversal behavior of some Maya search algorithms which traverse the history/future of shape nodes looking for directly related nodes. More...

virtual Type	type () const
	Returns the type of node that this is. More...

virtual bool	isAbstractClass () const
	Override this class to return true if this node is an abstract node. More...

virtual MStringArray	getFilesToArchive (bool shortName=false, bool unresolvedName=false, bool markCouldBeImageSequence=false) const
	Use this method to return all external files used by this node. More...

virtual void	getExternalContent (MExternalContentInfoTable &table) const
	Returns the external content (files) that this node depends on. More...

bool	addExternalContentForFileAttr (MExternalContentInfoTable &table, const MObject &attr) const
	Adds content info to the specified table from a file path attribute. More...

bool	setExternalContentForFileAttr (const MObject &attr, const MExternalContentLocationTable &table)
	Sets content info in the specified attribute from the table. More...

virtual void	setExternalContent (const MExternalContentLocationTable &table)
	Changes the location of external content in batch. More...

virtual MTypeId	typeId () const
	Returns the TYPEID of this node. More...

virtual MString	typeName () const
	Returns the type name of this node. More...

virtual MString	name () const
	Returns the name of this particular instance of this class. More...

virtual MObject	thisMObject () const
	Returns the MObject associated with this user defined node. More...

virtual MStatus	setExistWithoutInConnections (bool flag)
	This method specifies whether or not the node can exist without input connections. More...

virtual bool	existWithoutInConnections (MStatus *ReturnStatus=NULL) const
	Determines whether or not this node can exist without input connections. More...

virtual MStatus	setExistWithoutOutConnections (bool flag)
	This method specifies whether or not the node can exist without output connections. More...

virtual bool	existWithoutOutConnections (MStatus *ReturnStatus=NULL) const
	Determines whether or not this node can exist without output connections. More...

Static Public Member Functions
static const char *	className ()
	Returns the name of this class. More...

Static Public Member Functions inherited from MPxNode
static MStatus	addAttribute (const MObject &attr)
	This method adds a new attribute to a user defined node type during the type's initialization. More...

static MStatus	inheritAttributesFrom (const MString &parentClassName)
	This method allows a class of plugin node to inherit all of the attributes of a second class of plugin node. More...

static MStatus	attributeAffects (const MObject &whenChanges, const MObject &isAffected)
	This method specifies that a particular input attribute affects a specific output attribute. More...

static const char *	className ()
	Returns the name of this class. More...

Static Public Attributes
static MObject	enableRestPosition
	Node attribute: enableRestPosition/erp - boolean. More...

static MObject	lockOutput
	Node attribute: lockOutput/lo - boolean. More...

Static Public Attributes inherited from MPxNode
static MObject	message
	message attribute

static MObject	isHistoricallyInteresting
	is historically interesting attribute

static MObject	caching
	caching attribute

static MObject	state
	state attribute

static MObject	frozen
	frozen attribute

Protected Member Functions
virtual const MObject	passiveOutputAttribute () const
	Returns the passive output attribute for the constraint. More...

virtual void	getOutputAttributes (MObjectArray &attributeArray)
	Returns output attributes for the constraint. More...

MStatus	closestPoint (const MObject &dataGeometryObject, const MPoint &toThisPoint, MPoint &theClosestPoint) const
	Returns the closest point on this surface to the given point. More...

MStatus	closestNormal (const MObject &dataGeometryObject, const MPoint &toThisPoint, MVector &theNormal) const
	Returns the closest normal on this surface to the given point. More...

MStatus	closestTangent (const MObject &dataGeometryObject, const MPoint &toThisPoint, MVector &theTangent) const
	Returns the closest tangent on this surface to the given point. More...

MEulerRotation	computeAim (const MMatrix &parentInverseMatrix, const MVector &targetVector, const MVector &aimVector, const MVector &upVector, const MVector &wupVector, MEulerRotation::RotationOrder order=MEulerRotation::kXYZ, const MQuaternion &jointOrient=MQuaternion::identity, MStatus *ResultStatus=NULL) const
	Returns the rotation which aligns the aimVector in local space with the targetVector in local space while keeping the upVector in local space and the wUpVector world space aligned as closely as possible. More...

MVector	worldUpVector (MPxConstraint::UpVectorType upType, const MVector &upVector, const MMatrix &upMatrix, const MPoint &constrPoint, MStatus *ResultStatus=NULL) const
	Returns the world up vector based on the requested up type. More...

MPoint	worldConstraintPoint (const MMatrix &parentInverseMatrix, const MVector &translate, const MVector &rotatePivot, const MVector &rotatePivotTranslate, MStatus *ResultStatus=NULL) const
	Returns the world constraint point. More...

Protected Member Functions inherited from MPxNode
virtual MDataBlock	forceCache (MDGContext &ctx=MDGContext::fsNormal)
	USE _forceCache() IN SCRIPT. More...

virtual void	setMPSafe (bool flag)
	USE _setMPSafe() IN SCRIPT. More...

virtual MStatus	setDoNotWrite (bool flag)
	USE _setDoNotWrite() IN SCRIPT. More...

virtual bool	doNotWrite (MStatus *ReturnStatus=NULL) const
	USE _doNotWrite() IN SCRIPT. More...

Member Enumeration Documentation

enum UpVectorType

The type of up vector.

Enumerator
kScene	Scene up vector.
kObject	Object up vector.
kObjectRotation	Object rotation up vector.
kVector	Specified vector.
kLast	Last value, used for counting.

Constructor & Destructor Documentation

MPxConstraint ( )

Constructor.

The constructor should never call any methods from MPxConstraint or make any calls that require the existence of the MObject associated with the user defined node. The postConstructor method should be used to do any initialization of this kind.

Member Function Documentation

const MObject weightAttribute ( ) const

virtual

Returns the weight attribute for the constraint.

Default implementation returns MObject::kNullObj.

Examples:: geometrySurfaceConstraint/geometrySurfaceConstraint.h.

const MObject targetAttribute ( ) const

virtual

Returns the target attribute for the constraint.

Default implementation returns MObject::kNullObj.

Examples:: geometrySurfaceConstraint/geometrySurfaceConstraint.h.

const MObject constraintRotateOrderAttribute ( ) const

virtual

Returns the rotate order attribute for the constraint.

Default implementation returns MObject::kNullObj.

If is only necessary to override this method if the constraint will control rotation.

const char * className ( )

static

Returns the name of this class.

Returns: The name of this class.

const MObject passiveOutputAttribute ( ) const

protectedvirtual

Returns the passive output attribute for the constraint.

Default implementation returns MObject::kNullObj.

Passive output attributes do not prevent value modifications to the destination attribute when connected.

void getOutputAttributes ( MObjectArray & attributeArray )

protectedvirtual

Returns output attributes for the constraint.

Default implementation clears the input attributeArray and returns.

Parameters

[out] attributeArray Array of output attributes.

Examples:: geometrySurfaceConstraint/geometrySurfaceConstraint.h.

MStatus closestPoint	(	const MObject &	dataGeometryObject,
		const MPoint &	toThisPoint,
		MPoint &	theClosestPoint
	)		const

protected

Returns the closest point on this surface to the given point.

Parameters

[in]	dataGeometryObject	surface
[in]	toThisPoint	the point to evaluate from
[out]	theClosestPoint	the calculated closest point

Returns: Status code

Status Codes:

MS::kSuccess The method was successful.
MS::kInvalidParameter dataGeometryObject is invalid.
MS::kFailure An object error has occurred.

MStatus closestNormal	(	const MObject &	dataGeometryObject,
		const MPoint &	toThisPoint,
		MVector &	theNormal
	)		const

protected

Returns the closest normal on this surface to the given point.

Parameters

[in]	dataGeometryObject	surface
[in]	toThisPoint	the point to evaluate from
[out]	theNormal	the calculated closest normal

Returns: Status code

Status Codes:

MS::kSuccess The method was successful.
MS::kInvalidParameter dataGeometryObject is invalid.
MS::kFailure An object error has occurred.

MStatus closestTangent	(	const MObject &	dataGeometryObject,
		const MPoint &	toThisPoint,
		MVector &	theTangent
	)		const

protected

Returns the closest tangent on this surface to the given point.

Parameters

[in]	dataGeometryObject	surface
[in]	toThisPoint	the point to evaluate from
[out]	theTangent	the calculated closest tangent

Returns: Status code

Status Codes:

MS::kSuccess The method was successful.
MS::kInvalidParameter dataGeometryObject is invalid.
MS::kFailure An object error has occurred.

MEulerRotation computeAim	(	const MMatrix &	parentInverseMatrix,
		const MVector &	targetVector,
		const MVector &	aimVector,
		const MVector &	upVector,
		const MVector &	wUpVector,
		MEulerRotation::RotationOrder	order = `MEulerRotation::kXYZ`,
		const MQuaternion &	jointOrient = `MQuaternion::identity`,
		MStatus *	ResultStatus = `NULL`
	)		const

protected

Returns the rotation which aligns the aimVector in local space with the targetVector in local space while keeping the upVector in local space and the wUpVector world space aligned as closely as possible.

Parameters

[in]	parentInverseMatrix
[in]	targetVector
[in]	aimVector
[in]	upVector
[in]	wUpVector
[in]	order
[in]	jointOrient
[out]	ResultStatus

Returns: Aim rotation.

Status Codes:

MS::kSuccess The method was successful.
MS::kFailure An object error has occurred.

MVector worldUpVector	(	MPxConstraint::UpVectorType	upType,
		const MVector &	upVector,
		const MMatrix &	upMatrix,
		const MPoint &	constrPoint,
		MStatus *	ResultStatus = `NULL`
	)		const

protected

Returns the world up vector based on the requested up type.

Parameters

[in]	upType
[in]	upVector
[in]	upMatrix
[in]	constrPoint
[out]	ResultStatus

Returns: World up vector.

Status Codes:

MS::kSuccess The method was successful.
MS::kFailure An object error has occurred.

MPoint worldConstraintPoint	(	const MMatrix &	parentInverseMatrix,
		const MVector &	translate,
		const MVector &	rotatePivot,
		const MVector &	rotatePivotTranslate,
		MStatus *	ResultStatus = `NULL`
	)		const

protected

Returns the world constraint point.

Parameters

[in]	parentInverseMatrix
[in]	translate
[in]	rotatePivot
[in]	rotatePivotTranslate
[out]	ResultStatus

Returns: World constraint point.

Status Codes:

MS::kSuccess The method was successful.
MS::kFailure An object error has occurred.

Member Data Documentation

MObject enableRestPosition

static

Node attribute: enableRestPosition/erp - boolean.

This attribute defines the constraint behavior when all weights are at zero.

If true, the constraint goes to the restTranslate position when all weights are zero. If false, the constraint output is not computed when all weights are zero.

MObject lockOutput

static

Node attribute: lockOutput/lo - boolean.

When enabled, the constrained object cannot be moved away from its constrained location, and a pairBlend will not be inserted if the user tries to keyframe the constrained attributes.

This allows for the pre-5.0 behavior of constraints. When disabled, the constrained object can be moved away from the constraint and a pairBlend will be inserted if the object is keyframed and the animation blending preference specifies that blending is enabled.

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

MPxConstraint.h
MPxConstraint.cpp

MPxConstraint Class Reference

Class Description

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation