Dependency node attribute function set. More...

#include <MFnAttribute.h>

Inheritance diagram for MFnAttribute:

Public Types
enum	DisconnectBehavior { kDelete, kReset, kNothing }
	Attribute behaviour on disconnect. More...

Public Member Functions
virtual MFn::Type	type () const
	Function set type. More...

virtual	~MFnAttribute ()
	Destructor.

	MFnAttribute ()
	Default constructor.

	MFnAttribute (MObject &object, MStatus *ReturnStatus=NULL)
	Constructor. More...

bool	isReadable (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is readable. More...

bool	isWritable (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is writable. More...

bool	isConnectable (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute accepts dependency graph connections. More...

bool	isStorable (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is to be stored when the node is saved to a file. More...

bool	isCached (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is cached locally in the node's data block. More...

bool	isArray (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute supports an array of data. More...

bool	indexMatters (MStatus *ReturnStatus=NULL) const
	Determines whether the user must specify an index when connecting to this attribute, or whether the next available index can be used. More...

bool	isKeyable (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is keyable. More...

bool	isChannelBoxFlagSet (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute has its channel box flag set. More...

bool	isHidden (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is to hidden from the UI. More...

bool	isUsedAsColor (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is to be presented as a color in the UI. More...

bool	isIndeterminant (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is indeterminant. More...

bool	isRenderSource (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is a render source. More...

bool	isDynamic (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is a dynamic attribute. More...

bool	isExtension (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is an extension attribute. More...

bool	isWorldSpace (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is worldspace. More...

bool	isAffectsWorldSpace (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute affects worldspace. More...

bool	isUsedAsFilename (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is to be used as a filename. More...

bool	affectsAppearance (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute affects the appearance of the object when rendering in the viewport. More...

bool	isProxyAttribute (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute is a proxy attribute. More...

DisconnectBehavior	disconnectBehavior (MStatus *ReturnStatus=NULL) const
	Returns the behavior of this attribute when it is disconnected. More...

bool	usesArrayDataBuilder (MStatus *ReturnStatus=NULL) const
	Returns true if this attribute uses an array data builder. More...

bool	internal (MStatus *ReturnStatus=NULL) const
	Returns true if a node has internal member data representing this attribute. More...

MStatus	setReadable (bool state)
	Sets whether this attribute should be readable. More...

MStatus	setWritable (bool state)
	Sets whether this attribute should be writable. More...

MStatus	setConnectable (bool state)
	Sets whether this attribute should allow dependency graph connections. More...

MStatus	setStorable (bool state)
	Sets whether this attribute should be storable. More...

MStatus	setCached (bool state)
	Sets whether the data for this attribute is cached locally in the node's data block. More...

MStatus	setArray (bool state)
	Sets whether this attribute should have an array of data. More...

MStatus	setIndexMatters (bool state)
	If the attribute is an array, then this method specifies whether to force the user to specify an index when connecting to this attribute, or to use the next available index. More...

MStatus	setKeyable (bool state)
	Sets whether this attribute should accept keyframe data. More...

MStatus	setChannelBox (bool state)
	Sets whether this attribute should appear in the channel box when the node is selected. More...

MStatus	setHidden (bool state)
	Sets whether this attribute should be hidden from the UI. More...

MStatus	setUsedAsColor (bool state)
	Sets whether this attribute should be presented as a color in the UI. More...

MStatus	setIndeterminant (bool state)
	Sets whether this attribute is indeterminant. More...

MStatus	setRenderSource (bool state)
	Sets whether this attribute should be used as a render source attribute. More...

MStatus	setWorldSpace (bool state)
	Sets whether this attribute should be treated as worldspace. More...

MStatus	setAffectsWorldSpace (bool state)
	Sets whether this attribute should affect worldspace. More...

MStatus	setUsedAsFilename (bool state)
	Sets whether this attribute should be presented as a filename in the UI. More...

MStatus	setAffectsAppearance (bool state)
	Sets whether this attribute affects the appearance of the object when rendering in the viewport. More...

MStatus	setProxyAttribute (bool state)
	Sets whether this attribute is a proxy attribute. More...

MStatus	setDisconnectBehavior (DisconnectBehavior behavior)
	Sets the disconnection behavior for this attribute. More...

MStatus	setUsesArrayDataBuilder (bool state)
	Sets whether this attribute uses an array data builder. More...

MStatus	setInternal (bool state)
	The function controls an attribute's data storage. More...

MStatus	setNiceNameOverride (const MString &localizedName)
	Sets the localized string which should be used for this attribute in the UI. More...

bool	acceptsAttribute (const MFnAttribute &attr, MStatus *ReturnStatus=NULL) const
	Returns true if this attribute can accept a connection with the given attribute. More...

bool	accepts (MFnData::Type type, MStatus *ReturnStatus=NULL) const
	Returns true if this attribute can accept a connection of the given type. More...

bool	accepts (const MTypeId &id, MStatus *ReturnStatus=NULL) const
	Returns true if this attribute can accept a connection of the given type. More...

MObject	parent (MStatus *ReturnStatus=NULL) const
	Get the parent of this attribute, if it has one. More...

MString	name (MStatus *ReturnStatus=NULL) const
	Returns the long name of the attribute. More...

MString	shortName (MStatus *ReturnStatus=NULL) const
	Returns the short name of the attribute. More...

MString	getAddAttrCmd (bool useLongName=false, MStatus *status=NULL) const
	Returns a string containing the addAttr command which would be required to recreate the attribute on a node. More...

MStatus	addToCategory (const MString &category)
	Add the attribute to the named category. More...

MStatus	removeFromCategory (const MString &category)
	Remove the attribute from the named category. More...

bool	hasCategory (const MString &category) const
	Check to see if the attribute belongs to the named category. More...

MStatus	getCategories (MStringArray &ReturnStatus) const
	Get all of the categories to which this attribute belongs. More...

	MFnAttribute (const MObject &object, MStatus *ReturnStatus=NULL)
	NO SCRIPT SUPPORT. More...

Public Member Functions inherited from MFnBase
virtual	~MFnBase ()
	Class Destructor. More...

bool	hasObj (MFn::Type) const
	Determines whether or not the Function Set is compatible with the specified Maya Object within the API RTTI system. More...

bool	hasObj (const MObject &) const
	Determines whether or not the Function Set is compatible with the specified Maya Object within the API RTTI system. More...

MObject	object (MStatus *ReturnStatus=nullptr) const
	Returns the MObject that is attached to the Function Set. More...

virtual MStatus	setObject (MObject &object)
	Attaches the Function Set to the specified Maya Object. More...

virtual MStatus	setObject (const MObject &object)
	NO SCRIPT SUPPORT. More...

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

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

static const char *	typeString (MFn::Type)
	Introduced in 2020.0 More...

static bool	isValid (MFn::Type)
	Introduced in 2020.0 More...

Detailed Description

Dependency node attribute function set.

MFnAttribute is the function set for dependency node attributes.

An attribute of a dependency node describes a piece of data that belongs to nodes of that type. For example, a node that makes a sphere might have a radius attribute. A node's attributes describe connections sites on the node that can be used in the dependency graph.

Attributes typically belong to a class of nodes, rather than to an individual node. For example, all sphere nodes have a radius. Even though a single attribute may be shared by all nodes of a given type, each node will have its own value for the attribute.

Attributes are hierarchical. For example, the translate scale attribute of a transform has x, y, and z child attributes.

By default, attributes are:

Readable.
Writable.
Connectable.
Storable.
Cached.
Not arrays.
Have indices that matter.
Do not use an array builder.
Not keyable.
Not hidden.
Not used as colors.
Not indeterminant.
Set to disconnect behavior kNothing.

Examples:: AbcBullet/AttributesWriter.cpp, AbcExport/AttributesWriter.cpp, AbcExport/MayaUtility.cpp, animExportUtil/animExportUtil.cpp, apiMeshShape/apiMeshShape.cpp, atomImportExport/atomAnimLayers.cpp, atomImportExport/atomCachedPlugs.cpp, atomImportExport/atomFileUtils.cpp, cgFx/cgfxAttrDef.cpp, cgFx/cgfxShaderNode.cpp, dagPoseInfoCmd/dagPoseInfoCmd.cpp, dx11Shader/dx11Shader.cpp, fileTexture/fileTexture.cpp, getAttrAffectsCmd/getAttrAffectsCmd.cpp, glslShader/GLSLShader.cpp, gpuCache/gpuCacheSubSceneOverride.cpp, and maTranslator/maTranslator.cpp.

Member Enumeration Documentation

enum DisconnectBehavior

Attribute behaviour on disconnect.

Enumerator
kDelete	Delete array element (array attributes only).
kReset	Reset the attribute to its default.
kNothing	Do nothing to the attribute's value.

Constructor & Destructor Documentation

MFnAttribute	(	MObject &	object,
		MStatus *	ReturnStatus = `NULL`
	)

Constructor.

Class constructor that initializes the function set to the given MObject.

Parameters

[in]	object	The MObject to attach the function set to
[out]	ReturnStatus	the return status

Status Codes:

MS::kSuccess if the function set is successfully attached
MS::kInvalidParameter if the MObject does not represent a valid Maya object or if the function set is not allowed to attach to this MObject

MFnAttribute	(	const MObject &	object,
		MStatus *	ReturnStatus = `NULL`
	)

NO SCRIPT SUPPORT.

Class constructor that initializes the function set to the given MObject.

Constructor

Parameters

[in]	object	The MObject to attach the function set to
[out]	ReturnStatus	the return status

Status Codes:

MS::kSuccess if the function set is successfully attached
MS::kInvalidParameter if the MObject does not represent a valid Maya object or if the function set is not allowed to attach to this MObject

Member Function Documentation

MFn::Type type ( ) const

virtual

Function set type.

Return the class type : MFn::kAttribute.

Returns: the class type.

Reimplemented from MFnBase.

Reimplemented in MFnCompoundAttribute, MFnNumericAttribute, MFnUnitAttribute, MFnGenericAttribute, MFnTypedAttribute, MFnMessageAttribute, MFnLightDataAttribute, MFnEnumAttribute, and MFnMatrixAttribute.

OPENMAYA_MAJOR_NAMESPACE_OPEN const char * className ( )

static

Returns the name of this class.

Return the class name : "MFnAttribute".

Returns: Name of this class.

bool isReadable ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is readable.

If an attribute is readable, then it can be used as the source in a dependency graph connection.

Attributes are readable by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is readable

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isWritable ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is writable.

If an attribute is writable, then it can be used as the destination in a dependency graph connection.

Attributes are writable by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is writable

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isConnectable ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute accepts dependency graph connections.

If it does, then the readable and writable methods will indicate what types of connections are accepted.

Attributes are connectable by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is connectable

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isStorable ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is to be stored when the node is saved to a file.

Attributes are storable by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is storable

Status Codes:

kSuccess operation successful
kFailure this function set does not have a valid attribute object

bool isCached ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is cached locally in the node's data block.

The default for this is true. Caching a node locally causes a copy of the attribute value for the node to be cached with the node. This removes the need to traverse through the graph to get the value each time it is requested.

Caching the value locally gives a speed increase at the cost of more memory.

Attributes are cached by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is cached locally

Status Codes:

kSuccess operation successful
kFailure this function set does not have a valid attribute object

bool isArray ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute supports an array of data.

Attributes are single elements by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute stores an array of data

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool indexMatters ( MStatus * ReturnStatus = NULL ) const

Determines whether the user must specify an index when connecting to this attribute, or whether the next available index can be used.

This method only applies to array attributes which are non readable, i.e. destination attributes.

This corresponds with the connectAttr command's -na/nextAvailable flag. If the destination attribute has set the indexMatters to be false with this flag specified, a connection is made to the next available index. No index need be specified

The index matters to attributes by default.

Parameters

[out] ReturnStatus return status

Returns

true The user must specify the index when connecting to this attribute using connectAttr
false The next available index can be used when connecting to this attribute using connectAttr -na

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isKeyable ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is keyable.

Keyable attributes will be keyed by AutoKey and the Set Keyframe UI. Non-keyable attributes prevent the user from setting keys via the obvious UI provided for keying. Being non-keyable is not a hard block against adding keys to an attribute.

This method determines the default keyability of a plug. The keyability can be changed after it is created. Use the MPlug::isKeyable method to determine whether or not a specific plug is keyable.

Attributes are not keyable by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is keyable

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isChannelBoxFlagSet ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute has its channel box flag set.

Attributes will appear in the channel box if their channel box flag is set or if they are keyable.

This method returns the default channel box display state of a plug. The display can be changed after it is created. Use the MPlug::isChannelBox method to determine whether or not a specific plug is displayed in the channel box.

Attributes are not in the channel box by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating the status of the channel box flag on this attribute

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isHidden ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is to hidden from the UI.

The attribute will not show up in attribute editors.

Attributes are not hidden by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is hidden

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isUsedAsColor ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is to be presented as a color in the UI.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is used as a color

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: AbcBullet/AttributesWriter.cpp, and AbcExport/AttributesWriter.cpp.

bool isIndeterminant ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is indeterminant.

If an attribute may or may not be used during an evaluation then it is indeterminant. This attribute classification is mainly used on rendering nodes to indicate that some attributes are not always used.

Attributes are not indeterminant by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is indeterminant

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isRenderSource ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is a render source.

This attribute is used on rendering nodes to override the rendering sampler info.

Attributes are not render source by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is render source

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isDynamic ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is a dynamic attribute.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is dynamic

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isExtension ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is an extension attribute.

An extension attribute is a class-level attribute which has been added dynamically to a node class. Because it is added at the class level, all nodes of that class will have the given attribute, and will only store the attribute's value if it differs from the default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is an extension attribute

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isWorldSpace ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is worldspace.

Attributes are not worldspace by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is worldspace

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isAffectsWorldSpace ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute affects worldspace.

Attributes do not affect worldspace by default.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute affects worldspace

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isUsedAsFilename ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is to be used as a filename.

In the UI this attr will be presented as a file name.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is used as a filename

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool affectsAppearance ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute affects the appearance of the object when rendering in the viewport.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute affects the appearance of the object when rendering in the viewport.

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool isProxyAttribute ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute is a proxy attribute.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute is a proxy attribute

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

MFnAttribute::DisconnectBehavior disconnectBehavior ( MStatus * ReturnStatus = NULL ) const

Returns the behavior of this attribute when it is disconnected.

The possible settings are as follows:

kDelete delete the element of the array that was connected. This is only used for array attributes
kReset reset the attribute to its default value
kNothing leave the attribute set to its last known value

Attributes have a default disconnect behavior of kNothing.

Parameters

[out] ReturnStatus return status

Returns: The disconnect behavior

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool usesArrayDataBuilder ( MStatus * ReturnStatus = NULL ) const

Returns true if this attribute uses an array data builder.

If so, then the MArrayDataBuilder class may be used with this attribute.

By default array attributes do not use an array data builder.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute uses an array data builder.

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool internal ( MStatus * ReturnStatus = NULL ) const

Returns true if a node has internal member data representing this attribute.

Parameters

[out] ReturnStatus return status

Returns: A boolean value indicating whether this attribute uses internal data

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

MStatus setReadable ( bool state )

Sets whether this attribute should be readable.

If an attribute is readable, then it can be used as the source in a dependency graph connection.

Attributes are readable by default.

Parameters

[in] state whether the attribute is to be readable

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: anisotropicShader/anisotropicShader.cpp, backfillShader/backfillShader.cpp, clearcoat.cpp, closestPointOnCurve/closestPointOnCurveNode.cpp, customComponentTagNode/customComponentTagNode.cpp, displacementShader/displacementShader.cpp, dynExprField/dynExprField.cpp, footPrintNode_AnimatedMaterial/footPrintNode_GeometryOverride_AnimatedMaterial.cpp, geometrySurfaceConstraint/geometrySurfaceConstraint.cpp, geometrytools.cpp, interpShader/interpShader.cpp, lambertShader/lambertShader.cpp, lightShader/lightShader.cpp, multiCurveNode/multiCurveNode.cpp, onbShader/onbShader.cpp, phongShader/phongShader.cpp, pointOnMeshInfo/pointOnMeshInfoNode.cpp, pointOnSubdNode/pointOnSubdNode.cpp, shadowMatteShader/shadowMatteShader.cpp, shiftNode/shiftNode.cpp, simpleEvaluationDraw/simpleEvaluationDraw.cpp, simpleEvaluationNode/simpleEvaluationNode.cpp, simplePhysicsEngine/simplePhysicsEngine.cpp, simpleSimulationNode/simpleSimulationNode.cpp, slopeShader/slopeShaderNode.cpp, stringFormatNode/stringFormatNode.cpp, testMTopologyEvaluator/testMTopologyEvaluator.cpp, volumeShader/volumeShader.cpp, and weightListNode/weightListNode.cpp.

MStatus setWritable ( bool state )

Sets whether this attribute should be writable.

If an attribute is writable, then it can be used as the destination in a dependency graph connection.

If both keyable and writable for an attribute are set to true it will be displayed in the channel box when the node is selected.

Attributes are writable by default.

Parameters

[in] state whether the attribute is to be writable

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: AbcImport/AlembicNode.cpp, anisotropicShader/anisotropicShader.cpp, arcLenNode/arcLenNode.cpp, backfillShader/backfillShader.cpp, cgFx/cgfxVector.cpp, circleNode/circleNode.cpp, clearcoat.cpp, closestPointOnCurve/closestPointOnCurveNode.cpp, customComponentTagNode/customComponentTagNode.cpp, displacementShader/displacementShader.cpp, dx11Shader/dx11Shader.cpp, dynExprField/dynExprField.cpp, exampleFalloff/smoothFalloffNode.cpp, footPrintManip/footPrintManip.cpp, footPrintNode/footPrintNode.cpp, footPrintNode_AnimatedMaterial/footPrintNode_GeometryOverride_AnimatedMaterial.cpp, footPrintNode_GeometryOverride/footPrintNode_GeometryOverride.cpp, genericAttributeNode/genericAttributeNode.cpp, geometrySurfaceConstraint/geometrySurfaceConstraint.cpp, geometrytools.cpp, glslShader/GLSLShader.cpp, hlslShader/hlslShader.cpp, interpShader/interpShader.cpp, jitterNode/jitterNode.cpp, lambertShader/lambertShader.cpp, latticeNoise/latticeNoiseNode.cpp, lightShader/lightShader.cpp, meshOpCmd/meshOpNode.cpp, MetadataSample/tweakMetadataNode.cpp, multiCurveNode/multiCurveNode.cpp, onbShader/onbShader.cpp, particleAttrNode/particleAttrNode.cpp, phongShader/phongShader.cpp, pointOnMeshInfo/pointOnMeshInfoNode.cpp, pointOnSubdNode/pointOnSubdNode.cpp, renderAccessNode/renderAccessNode.cpp, shadowMatteShader/shadowMatteShader.cpp, shellNode/shellNode.cpp, shiftNode/shiftNode.cpp, simpleEvaluationDraw/simpleEvaluationDraw.cpp, simpleEvaluationNode/simpleEvaluationNode.cpp, simplePhysicsEngine/simplePhysicsEngine.cpp, simpleSimulationNode/simpleSimulationNode.cpp, simpleSkipNode/simpleSkipNode.cpp, sineNode/sineNode.cpp, slopeShader/slopeShaderNode.cpp, splitUVCmd/splitUVNode.cpp, stringFormatNode/stringFormatNode.cpp, swissArmyManip/swissArmyManip.cpp, testMTopologyEvaluator/testMTopologyEvaluator.cpp, testNobjectNode/testNobjectNode.cpp, testNpassiveNode/testNpassiveNode.cpp, testNsolverNode/testNsolverNode.cpp, testNucleusNode/testNucleusNode.cpp, transCircleNode/transCircleNode.cpp, and volumeShader/volumeShader.cpp.

MStatus setConnectable ( bool state )

Sets whether this attribute should allow dependency graph connections.

This should only get called in the initialize call of your node creator.

Attributes are connectable by default.

Parameters

[in] state whether the attribute is to be connectable

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: basicMorphNode/basicMorphNode.cpp, buildRotationNode/buildRotationNode.cpp, cgFx/cgfxShaderNode.cpp, dx11Shader/dx11ConeAngleToHotspotConverter.cpp, footPrintNode_AnimatedMaterial/footPrintNode_GeometryOverride_AnimatedMaterial.cpp, footPrintNode_GeometryOverride/footPrintNode_GeometryOverride.cpp, MayaPluginForSpreticle/spReticleLoc.cpp, offsetNode/offsetNode.cpp, simplePhysicsEngine/simplePhysicsEngine.cpp, and testMTopologyEvaluator/testMTopologyEvaluator.cpp.

MStatus setStorable ( bool state )

Sets whether this attribute should be storable.

If an attribute is storable, then it will be writen out when the node is stored to a file. This should only get called in the initialize call of your node creator.

Attributes are storable by default.

NOTE: Typed attributes of setting MFnData::kDynArrayAttrs are not storable. Message attribute are also not storable.

Parameters

[in] state whether the attribute is to be storable

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: AbcImport/AlembicNode.cpp, animCubeNode/animCubeNode.cpp, anisotropicShader/anisotropicShader.cpp, backfillShader/backfillShader.cpp, basicMorphNode/basicMorphNode.cpp, blindDataShader/blindDataMesh.cpp, buildRotationNode/buildRotationNode.cpp, cgFx/cgfxVector.cpp, circleNode/circleNode.cpp, clearcoat.cpp, closestPointOnCurve/closestPointOnCurveNode.cpp, customComponentTagNode/customComponentTagNode.cpp, customImagePlane/customImagePlane.cpp, displacementShader/displacementShader.cpp, dx11Shader/dx11ConeAngleToHotspotConverter.cpp, dx11Shader/dx11Shader.cpp, dynExprField/dynExprField.cpp, exampleFalloff/smoothFalloffNode.cpp, footPrintManip/footPrintManip.cpp, footPrintNode_AnimatedMaterial/footPrintNode_GeometryOverride_AnimatedMaterial.cpp, footPrintNode_GeometryOverride/footPrintNode_GeometryOverride.cpp, fullLoftNode/fullLoftNode.cpp, gameInputDevice/gameInputDevice.cpp, genericAttributeNode/genericAttributeNode.cpp, geomShader/geomShader.cpp, glslShader/GLSLShader.cpp, hlslShader/hlslShader.cpp, hwPhongShader/hwPhongShader.cpp, interpShader/interpShader.cpp, jitterNode/jitterNode.cpp, lambertShader/lambertShader.cpp, lightShader/lightShader.cpp, meshOpCmd/meshOpNode.cpp, MetadataSample/tweakMetadataNode.cpp, offsetNode/offsetNode.cpp, onbShader/onbShader.cpp, particleAttrNode/particleAttrNode.cpp, phongShader/phongShader.cpp, pointOnMeshInfo/pointOnMeshInfoNode.cpp, pointOnSubdNode/pointOnSubdNode.cpp, renderAccessNode/renderAccessNode.cpp, sceneAssembly/assemblyDefinition.cpp, shadowMatteShader/shadowMatteShader.cpp, shellNode/shellNode.cpp, shiftNode/shiftNode.cpp, simpleEvaluationDraw/simpleEvaluationDraw.cpp, simpleEvaluationNode/simpleEvaluationNode.cpp, simpleLoftNode/simpleLoftNode.cpp, simplePhysicsEngine/simplePhysicsEngine.cpp, simpleSimulationNode/simpleSimulationNode.cpp, simpleSkipNode/simpleSkipNode.cpp, sineNode/sineNode.cpp, slopeShader/slopeShaderNode.cpp, splatDeformer/splatDeformer.cpp, splitUVCmd/splitUVNode.cpp, sseDeformer/sseDeformer.cpp, stringFormatNode/stringFormatNode.cpp, swissArmyManip/swissArmyManip.cpp, testFailureNode/testFailureNode.cpp, testMTopologyEvaluator/testMTopologyEvaluator.cpp, testNobjectNode/testNobjectNode.cpp, testNpassiveNode/testNpassiveNode.cpp, testNsolverNode/testNsolverNode.cpp, testNucleusNode/testNucleusNode.cpp, transCircleNode/transCircleNode.cpp, volumeShader/volumeShader.cpp, and vp2BlinnShader/vp2BlinnShader.cpp.

MStatus setCached ( bool state )

Sets whether the data for this attribute is cached locally in the node's data block.

The default for this is true. Caching a node locally causes a copy of the attribute value for the node to be cached with the node. This removes the need to traverse through the graph to get the value each time it is requested. This should only get called in the initialize call of your node creator.

Caching the value locally gives a speed increase at the cost of more memory.

Attributes are cached by default.

Parameters

[in] state whether the attribute is to be cached locally

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: closestPointOnCurve/closestPointOnCurveNode.cpp, customComponentTagNode/customComponentTagNode.cpp, footPrintNode/footPrintNode.cpp, hwPhongShader/hwPhongShader.cpp, pointOnMeshInfo/pointOnMeshInfoNode.cpp, pointOnSubdNode/pointOnSubdNode.cpp, and shellNode/shellNode.cpp.

MStatus setArray ( bool state )

Sets whether this attribute should have an array of data.

This should be set to true if the attribute needs to accept multiple incoming connections.

Attributes are single elements by default.

Parameters

[in] state whether the attribute is to have an array of data

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: AbcImport/AlembicNode.cpp, anisotropicShader/anisotropicShader.cpp, backfillShader/backfillShader.cpp, cameraSetSubclass/exCameraSet.cpp, cgFx/cgfxShaderNode.cpp, footPrintNode/footPrintNode.cpp, fullLoftNode/fullLoftNode.cpp, geometrySurfaceConstraint/geometrySurfaceConstraint.cpp, lambertShader/lambertShader.cpp, MayaPluginForSpreticle/spReticleLoc.cpp, multiCurveNode/multiCurveNode.cpp, onbShader/onbShader.cpp, phongShader/phongShader.cpp, sceneAssembly/assemblyDefinition.cpp, shadowMatteShader/shadowMatteShader.cpp, slopeShader/slopeShaderNode.cpp, stringFormatNode/stringFormatNode.cpp, testNsolverNode/testNsolverNode.cpp, testNucleusNode/testNucleusNode.cpp, and weightListNode/weightListNode.cpp.

MStatus setIndexMatters ( bool state )

If the attribute is an array, then this method specifies whether to force the user to specify an index when connecting to this attribute, or to use the next available index.

This corresponds with the connectAttr command's -na/nextAvailable flag. If the destination attribute has set the indexMatters to be false with this flag specified, a connection is made to the next available index. No index need be specified

This method will only affect array attributes with setReadable set to false, i.e. destination attributes.

The index matters to attributes by default.

Parameters

[in] state whether the attribute's index must be specified when connecting to this attribute using the connectAttr command

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kInvalidParameter attribute is readable
MS::kFailure this function set does not have a valid attribute object

Examples:: MayaPluginForSpreticle/spReticleLoc.cpp, slopeShader/slopeShaderNode.cpp, and stringFormatNode/stringFormatNode.cpp.

MStatus setKeyable ( bool state )

Sets whether this attribute should accept keyframe data.

This should only get called in the initialize call of your node creator. Keyable attributes will be keyed by AutoKey and the Set Keyframe UI. Non-keyable attributes prevent the user from setting keys via the obvious UI provided for keying. Being non-keyable is not a hard block against adding keys to an attribute.

This method changes the default state of a plug. The keyability of a specific plug can be changed using the MPlug::setKeyable method.

If both keyable and writable for an attribute are set to true it will be displayed in the channel box when the node is selected.

Attributes are not keyable by default.

Parameters

[in] state whether the attribute is to be keyable

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: AbcImport/AlembicNode.cpp, AbcImport/MeshHelper.cpp, AbcImport/NodeIteratorVisitorHelper.cpp, apiMeshShape/apiMeshCreator.cpp, atomImportExport/atomFileUtils.cpp, cgFx/cgfxAttrDef.cpp, cgFx/cgfxShaderNode.cpp, cgFx/cgfxVector.cpp, closestPointOnCurve/closestPointOnCurveNode.cpp, customComponentTagNode/customComponentTagNode.cpp, customImagePlane/customImagePlane.cpp, displacementShader/displacementShader.cpp, dx11Shader/dx11Shader.cpp, dynExprField/dynExprField.cpp, footPrintNode_AnimatedMaterial/footPrintNode_GeometryOverride_AnimatedMaterial.cpp, gameInputDevice/gameInputDevice.cpp, genericAttributeNode/genericAttributeNode.cpp, geometrySurfaceConstraint/geometrySurfaceConstraint.cpp, glslShader/GLSLShader.cpp, hlslShader/hlslShader.cpp, hwPhongShader/hwPhongShader.cpp, interpShader/interpShader.cpp, lambertShader/lambertShader.cpp, lightShader/lightShader.cpp, manipOverride/rockingTransform2.cpp, MayaPluginForSpreticle/spReticleLoc.cpp, meshOpCmd/meshOpNode.cpp, multiCurveNode/multiCurveNode.cpp, offsetNode/offsetNode.cpp, pointOnMeshInfo/pointOnMeshInfoNode.cpp, pointOnSubdNode/pointOnSubdNode.cpp, rockingTransform/rockingTransform.cpp, rockingTransformCheck/rockingTransform.cpp, shadowMatteShader/shadowMatteShader.cpp, shellNode/shellNode.cpp, simpleEvaluationDraw/simpleEvaluationDraw.cpp, simpleEvaluationNode/simpleEvaluationNode.cpp, simplePhysicsEngine/simplePhysicsEngine.cpp, simpleSimulationNode/simpleSimulationNode.cpp, simpleSpring/simpleSpring.cpp, slopeShader/slopeShaderNode.cpp, stringFormatNode/stringFormatNode.cpp, testMTopologyEvaluator/testMTopologyEvaluator.cpp, torusField/torusField.cpp, volumeShader/volumeShader.cpp, vp2BlinnShader/vp2BlinnShader.cpp, weightListNode/weightListNode.cpp, and yTwistNode/yTwistNode.cpp.

MStatus setChannelBox ( bool state )

Sets whether this attribute should appear in the channel box when the node is selected.

This should only get called in the initialize call of your node creator. Keyable attributes are always shown in the channel box so this flag is ignored on keyable attributes. It is for intended for use on non-keyable attributes which you want to appear in the channel box.

This method changes the default state of a plug. Channel box visibility for a specific plug can be changed using the MPlug::setChannelBox method.

Attributes are not in the channel box by default unless they are keyable.

Parameters

[in] state whether the attribute is to appear in the channel box

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: simplePhysicsEngine/simplePhysicsEngine.cpp.

MStatus setHidden ( bool state )

Sets whether this attribute should be hidden from the UI.

This is useful if the attribute is being used for blind data, or if it is being used as scratch space for a geometry calculation (should also be marked non-connectable in that case).

Attributes are not hidden by default.

Parameters

[in] state whether the attribute is to be hidden

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: AbcImport/AlembicNode.cpp, AbcImport/MeshHelper.cpp, anisotropicShader/anisotropicShader.cpp, apiMeshShape/apiMeshCreator.cpp, backfillShader/backfillShader.cpp, brickShader/brickShader.cpp, cellShader/cellShader.cpp, cgFx/cgfxShaderNode.cpp, checkerShader/checkerShader.cpp, clearcoat.cpp, depthShader/depthShader.cpp, displacementShader/displacementShader.cpp, exampleFalloff/smoothFalloffNode.cpp, fileTexture/fileTexture.cpp, flameShader/flameShader.cpp, footPrintNode_AnimatedMaterial/footPrintNode_GeometryOverride_AnimatedMaterial.cpp, footPrintNode_GeometryOverride/footPrintNode_GeometryOverride.cpp, gameInputDevice/gameInputDevice.cpp, geometrytools.cpp, geomShader/geomShader.cpp, hwPhongShader/hwPhongShader.cpp, interpShader/interpShader.cpp, lambertShader/lambertShader.cpp, lavaShader/lavaShader.cpp, lightShader/lightShader.cpp, MayaPluginForSpreticle/spReticleLoc.cpp, meshOpCmd/meshOpNode.cpp, noiseShader/noiseShader.cpp, onbShader/onbShader.cpp, phongShader/phongShader.cpp, shadowMatteShader/shadowMatteShader.cpp, shiftNode/shiftNode.cpp, simpleNoiseShader/simpleNoiseShader.cpp, simplePhysicsEngine/simplePhysicsEngine.cpp, simpleSimulationNode/simpleSimulationNode.cpp, slopeShader/slopeShaderNode.cpp, solidCheckerShader/solidCheckerShader.cpp, testNobjectNode/testNobjectNode.cpp, testNpassiveNode/testNpassiveNode.cpp, testNsolverNode/testNsolverNode.cpp, testNucleusNode/testNucleusNode.cpp, and volumeShader/volumeShader.cpp.

MStatus setUsedAsColor ( bool state )

Sets whether this attribute should be presented as a color in the UI.

Parameters

[in] state whether the attribute is to be presented as a color

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: AbcImport/NodeIteratorVisitorHelper.cpp, cgFx/cgfxAttrDef.cpp, interpShader/interpShader.cpp, lambertShader/lambertShader.cpp, MayaPluginForSpreticle/spReticleLoc.cpp, onbShader/onbShader.cpp, simpleNoiseShader/simpleNoiseShader.cpp, slopeShader/slopeShaderNode.cpp, transformDrawNode/transformDrawNode.cpp, and uiDrawManager/uiDrawManager.cpp.

MStatus setIndeterminant ( bool state )

Sets whether this attribute is indeterminant.

If an attribute may or may not be used during an evaluation then it is indeterminant. This attribute classification is mainly used on rendering nodes to indicate that some attributes are not always used.

Attributes are not indeterminant by default.

Parameters

[in] state whether the attribute indeterminant

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

MStatus setRenderSource ( bool state )

Sets whether this attribute should be used as a render source attribute.

When writing shader plug-ins, it is sometimes useful to be able to modify the sampler info, so upstream shading network can be re- evaluated with different sampler info values.

For example, if a shading node takes a 2D texture as input, the result color of the 2D texture is evaluated at the current sample's UV coordinates. Initializing uvCoords attributes as render source and modifing the U and V values, then setting it as output will modify the sampler info. Re-evaluating the input plug will cause the 2D texture to re-evaluate with the new U and V values, and return a different color to the shading node.

Only valid Maya rendering attributes can be set to render source.

The following code example demonstrates how this is done:

initialize()

...

creates attributes for uvCoord and set them to be render source

u = nAttr.create( "uCoord", "u", MFnNumericData::kFloat, 0.0 ); nAttr.setStorable(false); nAttr.setWritable(true); nAttr.setRenderSource(true); v = nAttr.create( "vCoord", "v", MFnNumericData::kFloat, 0.0 ); nAttr.setStorable(false); nAttr.setWritable(true); nAttr.setRenderSource(true); uv = nAttr.create( "uvCoord", "uv", u, v ); nAttr.setStorable(false); nAttr.setWritable(true); nAttr.setRenderSource(true);

need to have the output uv affect the input uv because we want the new uv values we set to cause other inputs to this node to evaluate

attributeAffects ( uv, uv );

...

compute()

...

get uv coordinates from the sampler

MDataHandle uH = data.inputValue( u, &stat); MDataHandle vH = data.inputValue( v, &stat); float oldU = uH.asFloat(); float oldV = vH.asFloat();

get shading color input at the current sampler's uv coordinates

MDataHandle colorH = data.inputValue( inColor, &stat); MFloatVector color = colorH.asFloatVector(); // color at the sampled uv location

evaluate input color at a different uv location:

set output uv coordinates back to sampler this is only possible because we've set uv to be render source

MDataHandle outUV = data.outputValue( uv ); outUV.set( oldU-0.01, oldV-0.01 );

get newly evaluated inColor at uv(oldU-0.01, oldV-0.01)

any shading node connected to inColor will get uvCoord values as we've supplied. Calling data.inputValue( inColor, &stat) causes it to re-evaluate the network again with the new uvCoord values.

colorH = data.inputValue( inColor, &stat); // evaluate again color = colorH.asFloatVector(); // color at the new uv location

...

outUV.set( oldU, oldV ); // set the values back before we exit

...

Parameters

[in] state whether the attribute is to be a render source

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: shiftNode/shiftNode.cpp.

MStatus setWorldSpace ( bool state )

Sets whether this attribute should be treated as worldspace.

Being worldspace indicates the attribute is dependent on the worldSpace transformation of this node, and will be marked dirty by any attribute changes in the hierarchy that affects the worldSpace transformation. The attribute needs to be an array since during instancing there are multiple worldSpace paths to the node & Maya requires one array element per path for worldSpace attributes.

NOTES: 1. Can only be used on array attributes. 2. This property is ignored on non-dag nodes. 3. The attribute should be affected by another attribute or have a connection. Otherwise, the attribute will not get computed and will not get dirty again.

Parameters

[in] state whether the attribute is to be presented as worldspace

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object or the attribute is not an array

Examples:: footPrintNode/footPrintNode.cpp.

MStatus setAffectsWorldSpace ( bool state )

Sets whether this attribute should affect worldspace.

NOTES: This property is ignored on non-dag nodes.

Parameters

[in] state whether the attribute should affect worldspace

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: manipOverride/rockingTransform2.cpp, rockingTransform/rockingTransform.cpp, and rockingTransformCheck/rockingTransform.cpp.

MStatus setUsedAsFilename ( bool state )

Sets whether this attribute should be presented as a filename in the UI.

Parameters

[in] state whether the attribute is to be presented as a filename

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: AbcImport/AlembicNode.cpp, dx11Shader/dx11Shader.cpp, glslShader/GLSLShader.cpp, gpuCache/gpuCacheShapeNode.cpp, and sceneAssembly/assemblyReference.cpp.

MStatus setAffectsAppearance ( bool state )

Sets whether this attribute affects the appearance of the object when rendering in the viewport.

Parameters

[in] state whether the attribute affects the appearance of the object when rendering in the viewport.

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: cgFx/cgfxAttrDef.cpp, cgFx/cgfxShaderNode.cpp, dx11Shader/dx11Shader.cpp, glslShader/GLSLShader.cpp, hwPhongShader/hwPhongShader.cpp, and vp2BlinnShader/vp2BlinnShader.cpp.

MStatus setProxyAttribute ( bool state )

Sets whether this attribute is a proxy attribute.

Parameters

[in] state whether the attribute is a proxy attribute.

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

MStatus setDisconnectBehavior ( MFnAttribute::DisconnectBehavior behavior )

Sets the disconnection behavior for this attribute.

This determines what happens when a connection to this attribute is deleted. This should only get called in the initialize call of your node creator.

The settings are as follows:

kDelete delete the element of the array that was connected. This is only used for array attributes
kReset reset the attribute to its default value
kNothing leave the attribute set to its last known value

Attributes have a default disconnect behavior of kNothing.

If the kDelete behaviour is set on an array attribute which is a compound, that will only handle the case where the connection is to the parent attribute not to its children. So breaking a connection to an element of the parent (e.g. node.parent[3]) would cause that element to be removed, but breaking a connection to a child (e.g. node.parent[3].child) would leave the element intact, even if it was the last such connection.

To have the parent array element deleted when the last connection to a child is broken, you must set the kDelete behaviour on the connectable children as well.

Parameters

[in] behavior the new disconnect behavior

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: geometrySurfaceConstraint/geometrySurfaceConstraint.cpp.

MStatus setUsesArrayDataBuilder ( bool state )

Sets whether this attribute uses an array data builder.

If true, then the MArrayDataBuilder class may be used with this attribute to generate its data. If false, MArrayDataHandle::builder will fail.

By default array attributes do not use an array data builder.

Parameters

[in] state whether the attribute uses an array data builder

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: AbcImport/AlembicNode.cpp, footPrintNode/footPrintNode.cpp, multiCurveNode/multiCurveNode.cpp, slopeShader/slopeShaderNode.cpp, and weightListNode/weightListNode.cpp.

MStatus setInternal ( bool state )

The function controls an attribute's data storage.

When set to true, the virtual methods MPxNode::setInternalValue() and MPxNode::getInternalValue() are invoked whenever the attribute value is set or queried, respectively. By default, attributes are not internal.

There are two reasons to set an attribute as 'internal'. The first, and simplest, is when you want notification that the attribute has been set, or queried. This allows you to invoke some related action. In this case getInternalValue() and setInternalValue() should return false to indicate that Maya can store the attribute's value in the data block, instead of your own custom structure.

The second use of internal attributes is to store the data in a structure other than the datablock. When MPxNode::setInternalValue() is called, the attribute's data can be transferred into your custom data structure. When getInternalValue( you can return your data. In this case getInternalValue() and setInternalValue() should return true to indicate that Maya should not store the attribute's value in the data block but use your own custom structure instead.

Parameters

[in] state whether the attribute uses internal data

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: cgFx/cgfxShaderNode.cpp, customImagePlane/customImagePlane.cpp, dx11Shader/dx11Shader.cpp, glslShader/GLSLShader.cpp, gpuCache/gpuCacheShapeNode.cpp, hlslShader/hlslShader.cpp, hwPhongShader/hwPhongShader.cpp, MayaPluginForSpreticle/spReticleLoc.cpp, sceneAssembly/assemblyReference.cpp, and testMTopologyEvaluator/testMTopologyEvaluator.cpp.

MStatus setNiceNameOverride ( const MString & localizedName )

Sets the localized string which should be used for this attribute in the UI.

The name given to an attribute when it is created is the name used to refer to it when the scene is written to a file. To ensure that the scene file is readable across all locales it is essential that the attribute have the same name in all locales. So if it's called 'keyLight' in an English locale then it must also be called 'keyLight' in French and Chinese locales.

The setNiceNameOverride() method provides a means for associating a more user-friendly name with the attribute, one which can change to accomodate the user's locale. If such a name is present then Maya will use it instead of the attribute's fixed name when displaying the attribute in various UI elements such as the Channel Box.

Parameters

[in] localizedName The name to use for the current locale.

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: dx11Shader/dx11Shader.cpp, and glslShader/GLSLShader.cpp.

bool acceptsAttribute	(	const MFnAttribute &	attr,
		MStatus *	ReturnStatus = `NULL`
	)		const

Returns true if this attribute can accept a connection with the given attribute.

Parameters

[in]	attr	attribute
[out]	ReturnStatus	return status

Returns: A boolean value indicating whether a connection with that attribute is valid

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool accepts	(	MFnData::Type	type,
		MStatus *	ReturnStatus = `NULL`
	)		const

Returns true if this attribute can accept a connection of the given type.

Parameters

[in]	type	data type
[out]	ReturnStatus	return status

Returns: A boolean value indicating whether a connection of that type is valid

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

bool accepts	(	const MTypeId &	id,
		MStatus *	ReturnStatus = `NULL`
	)		const

Returns true if this attribute can accept a connection of the given type.

Parameters

[in]	id	data type id
[out]	ReturnStatus	return status

Returns: A boolean value indicating whether a connection of that type is valid

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

MObject parent ( MStatus * ReturnStatus = NULL ) const

Get the parent of this attribute, if it has one.

Parameters

[out] ReturnStatus return status

Returns: The parent attribute

Status Codes:

MS::kSuccess operation successful
MS::kNotFound the attribute does not have a parent
MS::kFailure function set does not have a valid object

MString name ( MStatus * ReturnStatus = NULL ) const

Returns the long name of the attribute.

If the attribute has no long name then its short name is returned.

Parameters

[out] ReturnStatus The status of the resulting operation.

Returns: The name of the attribute.

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: cgFx/cgfxAttrDef.cpp, and getAttrAffectsCmd/getAttrAffectsCmd.cpp.

MString shortName ( MStatus * ReturnStatus = NULL ) const

Returns the short name of the attribute.

If the attribute has no short name then its long name is returned.

Parameters

[out] ReturnStatus The status of the resulting operation.

Returns: The name of the attribute.

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

MString getAddAttrCmd	(	bool	useLongName = `false`,
		MStatus *	status = `NULL`
	)		const

Returns a string containing the addAttr command which would be required to recreate the attribute on a node.

The command includes the terminating semicolon and is formatted as if for use with a selected node, meaning that it contains no node name.

To get the addAttr commands for a compound attribute and its children, use MFnCompoundAttribute::getAddAttrCmds.

Parameters

[in]	useLongName	if true, use the attribute's long name rather than its short name
[in]	status	The status of the resulting operation. addAttr command

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure operation failed
MS::kInvalidParameter function set is not bound to an attribute

MStatus addToCategory ( const MString & category )

Add the attribute to the named category.

Attributes can be associated with different categories to facilitate grouping related concepts. For example, these categories could be queried at runtime to customize the UI.

Parameters

[in] category New category to which the attribute is to be added

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

Examples:: cgFx/cgfxAttrDef.cpp, and dx11Shader/dx11Shader.cpp.

MStatus removeFromCategory ( const MString & category )

Remove the attribute from the named category.

Presumes membership in the named category and fails if that's not true.

Parameters

[in] category Category from which the attribute is to be removed

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kNotFound attribute was not in category
MS::kFailure this function set does not have a valid attribute object

bool hasCategory ( const MString & category ) const

Check to see if the attribute belongs to the named category.

Matching is done solely on the string so multiple categories with the same name will not be unique.

Parameters

[in] category Category to check for attribute membership

Returns: True if the attribute belongs to that category

MStatus getCategories ( MStringArray & categories ) const

Get all of the categories to which this attribute belongs.

Parameters

[in] categories An MStringArray which will be overwritten with the categories associated with this attribute.

Returns: Return status

Status Codes:

MS::kSuccess operation successful
MS::kFailure this function set does not have a valid attribute object

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

MFnAttribute.h
MFnAttribute.cpp

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation