MPxSurfaceShape Class Reference

This reference page is linked to from the following overview topics: Parent class descriptions, Shapes in Maya, Shape classes, Writing a shape, Components, Marking Menus.

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Detailed Description

Parent class of all user defined shapes.

MPxSurfaceShape is the parent class of all user defined shapes. User defined shapes are dependency nodes (and DAG nodes) which contain overridable drawing, selection, and component methods.

This class can be used to implement new kinds of shapes within Maya that can have selectable/manipulatable components and behave in a similar manner to the default shapes in maya.

The UI dependent aspects of the shape should be implemented in a class derived from MPxSurfaceShapeUI. This includes the drawing and interactive selection of the shape and any components that the shape implements.

Examples:

apiMeshShape.h, apiMeshShapeUI.cpp, and quadricShape.cpp.

#include <MPxSurfaceShape.h>

Inheritance diagram for MPxSurfaceShape:

List of all members.

Public Types
enum	MVertexCachingMode { kNoPointCaching, kSavePoints, kRestorePoints, kUpdatePoints }
	Vertex caching modes. More...
enum	MVertexOffsetMode { kNormal, kUTangent, kVTangent, kUVNTriad }
	Vertex offset modes. More...
enum	MatchResult {   kMatchOk, kMatchNone, kMatchTooMany, kMatchInvalidName,   kMatchInvalidAttribute, kMatchInvalidAttributeIndex, kMatchInvalidAttributeRange, kMatchInvalidAttributeDim }
	Return values for the matchComponent() method. More...
enum	MChildChanged { kObjectChanged, kBoundingBoxChanged }
	Scope of change. More...
Public Member Functions
	MPxSurfaceShape ()
	Class constructor.
virtual	~MPxSurfaceShape ()
	Class destructor.
virtual MPxNode::Type	type () const
	Returns the type of node that this is.
virtual bool	isBounded () const
	This method should be overridden to return true if the user supplies a bounding box routine.
virtual MBoundingBox	boundingBox () const
	This method should be overridden to return a bounding box for the shape.
virtual void	transformUsing (const MMatrix &mat, const MObjectArray &componentList)
	Transform the given components using the specified transformation matrix.
virtual void	transformUsing (const MMatrix &mat, const MObjectArray &componentList, MVertexCachingMode cachingMode, MPointArray *pointCache)
	Transform the given components using the specified transformation matrix.
virtual void	tweakUsing (const MMatrix &mat, const MObjectArray &componentList, MVertexCachingMode cachingMode, MPointArray *pointCache, MArrayDataHandle &handle)
	Transform the given components using the specified transformation matrix.
bool	convertToTweakNodePlug (MPlug &plug) const
	Check if a tweak node is connected to this node.
virtual bool	vertexOffsetDirection (MObject &component, MVectorArray &direction, MVertexOffsetMode mode, bool normalize)
	This method should be overridden if the shape supports components that can be moved in the direction of the normal or UV's using the move vertex normal tool.
virtual MObject	newControlPointComponent () const
	The default action of this method is to return an MFnSingleIndexedComponent (of type MFn::kMeshVertComponent) in order to support rigid skinning binds.
virtual void	componentToPlugs (MObject &component, MSelectionList &selectionList) const
	Converts the given component into a selection list of plugs.
virtual bool	match (const MSelectionMask &mask, const MObjectArray &componentList) const
	This method is used to check for matches between a selection type (or mask) and a given component.
virtual MatchResult	matchComponent (const MSelectionList &item, const MAttributeSpecArray &spec, MSelectionList &list)
	This method is used to convert the string representation of a component into a component object and to validate that the indices.
virtual MObject	createFullVertexGroup () const
	This method is used to create a component containing every vertex/CV in the object.
virtual bool	deleteComponents (const MObjectArray &componentList, MDoubleArray &undoInfo)
	This method should be overridden if the shape is to support deletion of components.
virtual bool	undeleteComponents (const MObjectArray &componentList, MDoubleArray &undoInfo)
	This method should be overridden if the shape is to support undeletion of components.
virtual MObject	localShapeInAttr () const
	Returns the input attribute of the shape.
virtual MObject	localShapeOutAttr () const
	Returns the local output attribute of the shape.
virtual MObject	worldShapeOutAttr () const
	Returns the world space output attribute of the shape.
virtual MObject	cachedShapeAttr () const
	Returns the cached shape attribute of the shape.
virtual MObject	geometryData () const
	Returns the geometry data of the shape.
virtual void	closestPoint (const MPoint &toThisPoint, MPoint &theClosestPoint, double tolerance)
	This method is used by Maya in functions (such as select) that require closest point information from your surface.
virtual bool	pointAtParm (const MPoint &atThisParm, MPoint &evaluatedPoint)
	This method is used by Maya in functions (such as select) that require point at parameter values.
virtual MPxGeometryIterator *	geometryIteratorSetup (MObjectArray &, MObject &, bool forReadOnly=false)
	This method should be overridden by the user to return a geometry iterator compatible with the user's geometry.
virtual bool	acceptsGeometryIterator (bool writeable=true)
	If the shape can supply a component iterator then then this method should be overridden to return true.
virtual bool	acceptsGeometryIterator (MObject &, bool writeable=true, bool forReadOnly=false)
	If the shape can supply a component iterator then then this method should be overridden to return true.
MObjectArray	activeComponents () const
	Returns a list of active (selected) components for the shape.
bool	hasActiveComponents () const
	This method is used to determine whether or not the shape has active (selected) components.
void	childChanged (MChildChanged=kObjectChanged)
	This method can be used to trigger the shape to recalculate its bounding box.
bool	isRenderable () const
	Returns true if the shape is a renderable shape.
void	setRenderable (bool)
	Specifies whether the shape is a renderable shape.
MMatrix	getWorldMatrix (MDataBlock &, unsigned int) const
	Returns MMatrix which takes a point from local object space to world space.
Static Public Member Functions
static const char *	className ()
	Returns the name of this class.
Static Public Attributes
static MObject	mControlPoints
	Control points for the derived shapes. Search for all occurrences
static MObject	mControlValueX
	X value of a control point. Search for all occurrences
static MObject	mControlValueY
	Y value of a control point. Search for all occurrences
static MObject	mControlValueZ
	Z value of a control point. Search for all occurrences
static MObject	nodeBoundingBox
	bounding box attribute Search for all occurrences
static MObject	nodeBoundingBoxMin
	bounding box minimum point Search for all occurrences
static MObject	nodeBoundingBoxMinX
	X component of boundingBoxMin. Search for all occurrences
static MObject	nodeBoundingBoxMinY
	Y component of boundingBoxMin. Search for all occurrences
static MObject	nodeBoundingBoxMinZ
	Z component of boundingBoxMin. Search for all occurrences
static MObject	nodeBoundingBoxMax
	bounding box maximum point Search for all occurrences
static MObject	nodeBoundingBoxMaxX
	X component of boundingBoxMax. Search for all occurrences
static MObject	nodeBoundingBoxMaxY
	Y component of boundingBoxMax. Search for all occurrences
static MObject	nodeBoundingBoxMaxZ
	Z component of boundingBoxMax. Search for all occurrences
static MObject	nodeBoundingBoxSize
	bounding box size vector Search for all occurrences
static MObject	nodeBoundingBoxSizeX
	X component of boundingBoxSize. Search for all occurrences
static MObject	nodeBoundingBoxSizeY
	Y component of boundingBoxSize. Search for all occurrences
static MObject	nodeBoundingBoxSizeZ
	Z component of boundingBoxSize. Search for all occurrences
static MObject	center
	object center attribute Search for all occurrences
static MObject	boundingBoxCenterX
	X component of boundingBoxCenter. Search for all occurrences
static MObject	boundingBoxCenterY
	Y component of boundingBoxCenter. Search for all occurrences
static MObject	boundingBoxCenterZ
	Z component of boundingBoxCenter. Search for all occurrences
static MObject	matrix
	matrix attribute Search for all occurrences
static MObject	inverseMatrix
	inverse matrix attribute Search for all occurrences
static MObject	worldMatrix
	world matrix attribute Search for all occurrences
static MObject	worldInverseMatrix
	inverse world matrix attribute Search for all occurrences
static MObject	parentMatrix
	parent matrix attribute Search for all occurrences
static MObject	parentInverseMatrix
	inverse parent matrix attribute Search for all occurrences
static MObject	visibility
	visibility attribute Search for all occurrences
static MObject	intermediateObject
	intermediate object attribute Search for all occurrences
static MObject	isTemplated
	template attribute Search for all occurrences
static MObject	instObjGroups
	instances object group info attribute Search for all occurrences
static MObject	objectGroups
	object groups attributes Search for all occurrences
static MObject	objectGrpCompList
	component in object groups attribute Search for all occurrences
static MObject	objectGroupId
	group id attribute Search for all occurrences
static MObject	objectGroupColor
	group id attribute Search for all occurrences
static MObject	useObjectColor
	controls choice of wireframe dormant object color Search for all occurrences
static MObject	objectColor
	the per object dormant wireframe color Search for all occurrences

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Member Enumeration Documentation

enum MVertexCachingMode

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Vertex caching modes.

Enumerator:

kNoPointCaching	No point caching. Search for all occurrences
kSavePoints	Points should be saved for undo in the point cache. Search for all occurrences
kRestorePoints	Points should be restored from the point cache. Search for all occurrences
kUpdatePoints	Update the points. Search for all occurrences

enum MVertexOffsetMode

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Vertex offset modes.

Enumerator:

kNormal	Move in normal direction. Search for all occurrences
kUTangent	Move in u tangent direction. Search for all occurrences
kVTangent	Move in v tangent direction. Search for all occurrences
kUVNTriad	Calculate u, v, and normal offsets. Search for all occurrences

enum MatchResult

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Return values for the matchComponent() method.

Enumerator:

kMatchOk	The component was matched without error. Search for all occurrences
kMatchNone	No component was matched. Search for all occurrences
kMatchTooMany	Not used. Search for all occurrences
kMatchInvalidName	One of the names in the attribute specification was not valid. Search for all occurrences
kMatchInvalidAttribute	Not used. Search for all occurrences
kMatchInvalidAttributeIndex	The attribute specification contained an index for a non-array attribute. Search for all occurrences
kMatchInvalidAttributeRange	An attribute index was out of range. Search for all occurrences
kMatchInvalidAttributeDim	The attribute specification provided the wrong number of dimensions for an attribute. Search for all occurrences

enum MChildChanged

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Scope of change.

Enumerator:

kObjectChanged	Object geometry changed. Internal caches need to be updated. Search for all occurrences
kBoundingBoxChanged	Object geometry is unchanged but its bounding box has changed. This might happen if the object was moved or an offset changed. Search for all occurrences

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Constructor & Destructor Documentation

MPxSurfaceShape

(

)

Class constructor.

Any calls the MPxSurfaceShape methods must be done in the postConstructor method and not here.

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Member Function Documentation

MPxNode::Type type

(

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const [virtual]

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Returns the type of node that this is.

This is used to differentiate user defined nodes that are derived off different MPx base classes.

It is not necessary to override this method.

Returns:

Type of the node (MPxNode::kSurfaceShape)

Reimplemented from MPxNode.

bool isBounded

(

)

const [virtual]

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This method should be overridden to return true if the user supplies a bounding box routine.

Supplying a bounding box routine makes refresh and selection more efficient.

Returns:

A boolean value indicating whether a bounding box routine has been supplied

Examples:

apiMeshShape.h, and quadricShape.cpp.

MBoundingBox boundingBox

(

)

const [virtual]

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This method should be overridden to return a bounding box for the shape.

If this method is overridden, then MPxSurfaceShape::isBounded should also be overridden to return true.

Returns:

The bounding box of the shape

Examples:

apiMeshShape.h, apiMeshShapeUI.cpp, and quadricShape.cpp.

void transformUsing	(	const MMatrix &	matrix,
		const MObjectArray &	componentList
	)		[virtual]

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Transform the given components using the specified transformation matrix.

This method should be overridden if the shape supports components that can be transformed using maya's move, scale, and rotate tools.

Parameters:

[in]	matrix	the matrix representing the transformation that is to be applied to the components
[in]	componentList	a list of components to be tranformed. If the list is empty, it indicates that every point in the geometry should be transformed.

Reimplemented in MPxComponentShape.

Examples:

apiMeshShape.h.

void transformUsing	(	const MMatrix &	mat,
		const MObjectArray &	componentList,
		MVertexCachingMode	cachingMode,
		MPointArray *	pointCache
	)		[virtual]

Search for all occurrences

Transform the given components using the specified transformation matrix.

This method should be overridden if the shape supports components that can be transformed using maya's move, scale, and rotate tools.

Parameters:

[in]	mat	the matrix representing the transformation that is to be applied to the components
[in]	componentList	a list of components to be transformed. If the list is empty, it indicates that every point in the geometry should be transformed.
[in]	cachingMode	whether the points should be cached in the pointCache argument, or restored from the pointCache
[in]	pointCache	used to store for undo and restore points during undo

Reimplemented in MPxComponentShape.

void tweakUsing	(	const MMatrix &	mat,
		const MObjectArray &	componentList,
		MVertexCachingMode	cachingMode,
		MPointArray *	pointCache,
		MArrayDataHandle &	handle
	)		[virtual]

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Transform the given components using the specified transformation matrix.

This method should be overridden if the shape supports components that can be transformed using maya's move, scale, and rotate tools. This method is called when the shape has history & connected to a tweak node. The most common reason why the shape would be connected to a tweak node is if it is being deformed. When a shape is connected to a tweak node, transformations applied to the points are placed in the tweak node rather than in the shape itself.

Parameters:

[in]	mat	the matrix representing the transformation that is to be applied to the components
[in]	componentList	a list of components to be tranformed. If the list is empty, it indicates that every point in the geometry should be transformed.
[in]	cachingMode	whether the points should be cached in the pointCache argument, or restored from the pointCache
[in]	pointCache	used to store for undo and restore points during undo
[in]	handle	array data handle where the tweaks are stored

Examples:

apiMeshShape.h.

bool convertToTweakNodePlug

(

MPlug &

plug

)

const

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Check if a tweak node is connected to this node.

If it is, then reset the supplied plug to contain the controlPoints attribute on the tweak node.

Parameters:

[in]

plug

plug which will be set to point to the associated tweak node plug if a tweak node is connected

Returns:

true if a tweak node was found, false if the plug was unchanged

bool vertexOffsetDirection	(	MObject &	component,
		MVectorArray &	direction,
		MVertexOffsetMode	mode,
		bool	normalize
	)		[virtual]

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This method should be overridden if the shape supports components that can be moved in the direction of the normal or UV's using the move vertex normal tool.

This method should calculate the offset direction for a vertex components. The direction vector array is an array of offsets corresponding to the elements in the component. The mode argument specifies the type of movement that is being performed.

The default for this method is to return false, i.e. no support for move normal tool.

Parameters:

[in]	component
[in]	direction
[in]	mode	The type of vertex movement

• mode = 0 -> normal
• mode = 1 -> U
• mode = 2 -> V
• mode = 3 -> UVN triad

Parameters:

[in]

normalize

specifies whether the offset vectors should be normalized

Returns:

true if the shape supports the current mode, false if the shape cannot do the requested vertex move

Examples:

apiMeshShape.h.

MObject newControlPointComponent

(

)

const [virtual]

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The default action of this method is to return an MFnSingleIndexedComponent (of type MFn::kMeshVertComponent) in order to support rigid skinning binds.

This method can be overriden to support other types of components such as MFnDoubleIndexedComponent and MFnTripleIndexedComponent and should return a new component of that type. The types allowed are those listed in the create() method docs for each MFn*IndexedComponent.

No argument is required.

The skinning code handles the deallocation of the new component.

Returns:

The new component

void componentToPlugs	(	MObject &	component,
		MSelectionList &	list
	)		const [virtual]

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Converts the given component into a selection list of plugs.

This method is used to associate a shapes components into the corresponding attributes (plugs) within the shape. For example, it gets called by the translate manipulator to determine which attributes should be driven by the manipulator, and by the setKeyframe command to determine where to connect animCurves for components.

This method should be overridden if the shape supports components that can be selected and moved in Maya.

Parameters:

[in]	component	the component to be converted
[in]	list	a selection list where the plug should be added

Reimplemented in MPxComponentShape.

Examples:

apiMeshShape.h.

bool match	(	const MSelectionMask &	mask,
		const MObjectArray &	componentList
	)		const [virtual]

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This method is used to check for matches between a selection type (or mask) and a given component.

If your shape has components representing attributes then this method is used to match up your components with selection masks.

This is used by sets and deformers to make sure that the selected components fall into the "vertex only" category. This is useful when you want to make sure that only a particular component can be deformed.

Parameters:

[in]	mask	the selection mask to test against
[in]	componentList	a list of components to be tested

Returns:

• true the match was successfull
• false the match failed

Reimplemented in MPxComponentShape.

Examples:

apiMeshShape.h.

MPxSurfaceShape::MatchResult matchComponent	(	const MSelectionList &	item,
		const MAttributeSpecArray &	spec,
		MSelectionList &	list
	)		[virtual]

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This method is used to convert the string representation of a component into a component object and to validate that the indices.

This method should be overridden if the shape has components.

Parameters:

[in]	item	DAG selection item for the object being matched
[in]	spec	attribute specification object
[in]	list	list to add components to

Returns:

The component match result

Examples:

apiMeshShape.cpp, and apiMeshShape.h.

MObject createFullVertexGroup

(

)

const [virtual]

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This method is used to create a component containing every vertex/CV in the object.

This method is supposed to return non-NULL only if the dag object contains vertices/CVs (control points), so derived classes that do should override this method.

Eg: use MFnSingleIndexedComponent::setCompleteData( numVertices ) to specify that a component represents all the vertices of the shape.

Returns:

A component containing all of the vertices in the shape.

Reimplemented in MPxComponentShape.

Examples:

apiMeshShape.h.

bool deleteComponents	(	const MObjectArray &	componentList,
		MDoubleArray &	undoInfo
	)		[virtual]

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This method should be overridden if the shape is to support deletion of components.

A list of components to be deleted will be passed in as well as an array of doubles where information about each deleted component can be stored for undo purposes. A typical use for this array is to store knot values or weights for control points that are deleted.

Parameters:

[in]	componentList	List of components to be deleted
[in]	undoInfo	Values used for undo purposes

Returns:

true if this method was successful, false otherwise

bool undeleteComponents	(	const MObjectArray &	componentList,
		MDoubleArray &	undoInfo
	)		[virtual]

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This method should be overridden if the shape is to support undeletion of components.

A list of components to be deleted will be passed in as well as an array of doubles where information about each deleted component is stored for undo purposes. A typical use for this array is to store knot values or weights for control points that are deleted.

Parameters:

[in]	componentList	List of components that were deleted
[in]	undoInfo	Values used for undo purposes

Returns:

true if this method was successful, false otherwise

MObject localShapeInAttr

(

)

const [virtual]

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Returns the input attribute of the shape.

This method will be called by Maya to determine if the shape has construction history.

Returns:

The input attribute

Reimplemented in MPxComponentShape.

Examples:

apiMeshShape.h.

MObject localShapeOutAttr

(

)

const [virtual]

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Returns the local output attribute of the shape.

Returns:

The output attribute

Examples:

apiMeshShape.h.

MObject worldShapeOutAttr

(

)

const [virtual]

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Returns the world space output attribute of the shape.

Returns:

The world space output attribute

Examples:

apiMeshShape.h.

MObject cachedShapeAttr

(

)

const [virtual]

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Returns the cached shape attribute of the shape.

Returns:

The attribute that stores the cached shape

Examples:

apiMeshShape.h.

MObject geometryData

(

)

const [virtual]

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Returns the geometry data of the shape.

The geometry data must be derived from the MPxGeometryData class.

The data is used by Maya to add, edit and query component grouping (set) information for the shape. This set information is stored and managed by Maya's shape base class, geometryShape.

Returns:

The geometry data of the shape

Examples:

apiMeshShape.h.

void closestPoint	(	const MPoint &	toThisPoint,
		MPoint &	theClosestPoint,
		double	tolerance
	)		[virtual]

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This method is used by Maya in functions (such as select) that require closest point information from your surface.

Parameters:

[in]	toThisPoint	the point to test against
[out]	theClosestPoint	the closest point on your surface
[in]	tolerance	tolerance to use in your calculations

Examples:

apiMeshShape.h.

bool pointAtParm	(	const MPoint &	atThisParm,
		MPoint &	evaluatedPoint
	)		[virtual]

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This method is used by Maya in functions (such as select) that require point at parameter values.

This only makes sense for parametric surfaces such as NURBS.

Parameters:

[in]	atThisParm	the parameter to check
[out]	evaluatedPoint	the surface point

Returns:

true if a point was found, false otherwise

MPxGeometryIterator * geometryIteratorSetup	(	MObjectArray &	componentList,
		MObject &	components,
		bool	forReadOnly = false
	)		[virtual]

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This method should be overridden by the user to return a geometry iterator compatible with the user's geometry.

A geometry iterator is used for iterating over the components of a shape, such as the vertices of a mesh, in a generic manner.

The components to be iterated over are passed to this function in on of two ways, as a list of components, or as a single component. Only one of these arguments is used at any particular time.

Parameters:

[in]	componentList	a list of components to be iterated over
[in]	components	the components to be iterated over
[in]	forReadOnly	specifies whether the iterator is for read-only

Returns:

The component match result

Examples:

apiMeshShape.h, and apiSimpleShape.h.

bool acceptsGeometryIterator

(

bool

writeable = true

)

[virtual]

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If the shape can supply a component iterator then then this method should be overridden to return true.

The default is to return false.

Parameters:

[in]

writeable

is this component type writable by an iterator

Returns:

• true the shape can supply an iterator
• false the shape cannot supply an iterator

Examples:

apiMeshShape.h, and apiSimpleShape.h.

bool acceptsGeometryIterator	(	MObject &	component,
		bool	writeable = true,
		bool	forReadOnly = false
	)		[virtual]

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If the shape can supply a component iterator then then this method should be overridden to return true.

The default is to return false. The component argument can be used to when the shape has multiple components and not all of them can be iterator over.

Parameters:

[in]	component	the component to test
[in]	writeable	is this component type writable by an iterator
[in]	forReadOnly	is this component type readable by an iterator

Returns:

• true the shape can supply an iterator
• false the shape cannot supply an iterator

MObjectArray activeComponents

(

)

const

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Returns a list of active (selected) components for the shape.

Returns:

An array of active components

bool hasActiveComponents

(

)

const

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This method is used to determine whether or not the shape has active (selected) components.

Returns:

• true there are active components
• false there are no active components

void childChanged

(

MChildChanged

state = kObjectChanged

)

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This method can be used to trigger the shape to recalculate its bounding box.

Parameters:

[in]

state

the type of change that has occurred

bool isRenderable

(

)

const

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Returns true if the shape is a renderable shape.

Making a shape renderable allows the shape to have shading group assignments.

Returns:

• true the shape is renderable
• false the shape is not renderable

void setRenderable

(

bool

flag

)

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Specifies whether the shape is a renderable shape.

Making a shape renderable allows the shape to have shading group assignments.

Parameters:

[in]

flag

true if the shape is to be renderable, false otherwise

MMatrix getWorldMatrix	(	MDataBlock &	block,
		unsigned int	instanceGeom
	)		const

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Returns MMatrix which takes a point from local object space to world space.

Parameters:

[in]	block	a MDataBlock
[in]	instanceGeom	the instance this MPxSurfaceShape corresponds to

const char * className

(

)

[static]

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Returns the name of this class.

Returns:

The name of this class.

Reimplemented from MPxNode.