Dependency Graph Iterator. More...

#include <MItDependencyGraph.h>

Public Types
enum	Direction { kDownstream, kUpstream }
	Direction within the DG relative to root Node or Plug. More...

enum	Traversal { kDepthFirst, kBreadthFirst }
	Perform a depth first or breadth first traversal. More...

enum	Level { kNodeLevel, kPlugLevel }
	Level of detail of the iteration. More...

enum	Relationship { kDependsOn, kConnectedTo, kEvaluationGraph }
	What kind of relationship to follow. More...

Public Member Functions
	MItDependencyGraph (MObject &rootNode, MFn::Type filter=MFn::kInvalid, Direction direction=kDownstream, Traversal traversal=kDepthFirst, Level level=kNodeLevel, MStatus *ReturnStatus=NULL)
	Constructor for a DG Iterator with a root node. More...

	MItDependencyGraph (MPlug &rootPlug, MFn::Type filter=MFn::kInvalid, Direction direction=kDownstream, Traversal traversal=kDepthFirst, Level level=kPlugLevel, MStatus *ReturnStatus=NULL)
	Constructor for a DG Iterator with a root plug. More...

	MItDependencyGraph (MObject &rootNode, MPlug &rootPlug, MIteratorType &infoObject, Direction direction=kDownstream, Traversal traversal=kDepthFirst, Level level=kNodeLevel, MStatus *ReturnStatus=NULL)
	Constructor for a DG Iterator with a root node or a root plug. More...

	MItDependencyGraph (MObject &rootNode, MFn::Type filter, Direction direction, Traversal traversal, Level level, Relationship relationship, MStatus *ReturnStatus=NULL)
	Constructor for a DG Iterator with a root node. More...

	MItDependencyGraph (MPlug &rootPlug, MFn::Type filter, Direction direction, Traversal traversal, Level level, Relationship relationship, MStatus *ReturnStatus=NULL)
	Constructor for a DG Iterator with a root plug. More...

	MItDependencyGraph (MObject &rootNode, MPlug &rootPlug, MIteratorType &infoObject, Direction direction, Traversal traversal, Level level, Relationship relationship, MStatus *ReturnStatus=NULL)
	Constructor for a DG Iterator with a root node or a root plug. More...

	~MItDependencyGraph ()
	Class destructor.

MStatus	reset ()
	Clears iterator data and resets the iterator to the root node or plug. More...

MStatus	resetTo (MObject &rootNode, MFn::Type filter=MFn::kInvalid, Direction direction=kDownstream, Traversal traversal=kDepthFirst, Level level=kNodeLevel, Relationship relationship=kDependsOn)
	Clears iterator data and re-initializes the iterator. More...

MStatus	resetTo (MPlug &rootPlug, MFn::Type filter=MFn::kInvalid, Direction direction=kDownstream, Traversal traversal=kDepthFirst, Level level=kPlugLevel, Relationship relationship=kDependsOn)
	Clears iterator data and re-initializes the iterator. More...

MStatus	resetTo (MObject rootNode, MPlug rootPlug, MIteratorType &infoObject, Direction direction=kDownstream, Traversal traversal=kDepthFirst, Level level=kPlugLevel, Relationship relationship=kDependsOn)
	Clears iterator data and re-initializes the iterator. More...

MObject	rootNode (MStatus *ReturnStatus=NULL)
	Retrieves the root node of the iteration. More...

MPlug	rootPlug (MStatus *ReturnStatus=NULL)
	Retrieves the root plug of the iteration. More...

MFn::Type	currentFilter (MStatus *ReturnStatus=NULL)
	Retrieves the current node type filter. More...

MStatus	setCurrentFilter (MFn::Type filter=MFn::kInvalid)
	Sets the node or plug filter. More...

MStatus	resetFilter ()
	Resets the node or plug filter to default, MFn::kInvalid (filter disabled). More...

bool	isPruningOnFilter (MStatus *ReturnStatus=NULL)
	Tests whether or not the iteration path is pruned automatically at nodes or plugs which do not match the filter. More...

MStatus	enablePruningOnFilter ()
	Enables automatic pruning of iteration path at nodes or plugs which do not match the filter. More...

MStatus	disablePruningOnFilter ()
	Disables automatic pruning of iteration path at nodes or plugs which do not match the filter. More...

bool	isDirectionDownStream (MStatus *ReturnStatus=NULL)
	Tests whether or not the iteration is moving downstream (in the direction of data flow) in the DG. More...

Direction	currentDirection (MStatus *ReturnStatus=NULL)
	Reports the direction of the iteration through the graph. More...

MStatus	toggleDirection ()
	Toggles the direction of the iteration. More...

bool	isTraversalDepthFirst (MStatus *ReturnStatus=NULL)
	Tests whether or not the iteration is proceeding depth first (away from the root of the iteration) in the DG. More...

Traversal	currentTraversal (MStatus *ReturnStatus=NULL)
	Reports the traversal mode of the iteration through the graph. More...

MStatus	toggleTraversal ()
	Toggles the traversal of the iteration. More...

bool	atNodeLevel (MStatus *ReturnStatus=NULL)
	Tests whether or not the iteration is at the node level of detail (every node is visited only once) in the DG. More...

Level	currentLevel (MStatus *ReturnStatus=NULL)
	Reports the level of the iteration through the graph. More...

Relationship	currentRelationship (MStatus *ReturnStatus=NULL)
	Reports the relationship mode of the iteration through the graph. More...

MStatus	setCurrentRelationship (Relationship relationship)
	Sets the relationship mode of the iteration. More...

MStatus	setTraversalOverWorldSpaceDependents (bool val)
	This method controls whether the iterator will include world-space attribute dependencies in its traversal. More...

bool	isTraversingOverWorldSpaceDependents (MStatus *ReturnStatus=NULL)
	Tests whether the iterator is set to traverse world-space attribute dependencies. More...

MStatus	toggleLevel ()
	Toggles the level of the iteration. More...

MStatus	next ()
	Iterates to the next node or plug in accordance with the direction, traversal, level and filter. More...

bool	isDone (MStatus *ReturnStatus=NULL)
	Indicates whether or not all nodes or plugs have been iterated over in accordance with the direction, traversal, level and filter. More...

MStatus	prune ()
	Prunes the search path at the current plug. More...

MObject	thisNode (MStatus *ReturnStatus=NULL)
	This method is obsolete. More...

MObject	currentItem (MStatus *ReturnStatus=NULL)
	Retrieves the current node of the iteration. More...

bool	thisNodeHasUnknownType (MStatus *ReturnStatus=NULL)
	Indicates whether or not the current node has an unrecognised type. More...

MPlug	thisPlug (MStatus *ReturnStatus=NULL)
	Retrieves the current plug of the iteration. More...

MPlug	previousPlug (MStatus *ReturnStatus=NULL)
	Retrieves the previous plug of the iteration. More...

MStatus	getNodesVisited (MObjectArray &nodesVisted) const
	Retrieves all nodes visited during the iteration. More...

MStatus	getPlugsVisited (MPlugArray &plugsVisted) const
	Retrieves all plugs visited during the iteration. More...

MStatus	getNodePath (MObjectArray &path) const
	Retrieves the direct path from the current node to the root node. More...

MStatus	getPlugPath (MPlugArray &path) const
	Retrieves the direct path from the current plug to the root plug, with the current plug in element 0 of the array and the root plug in the final element of the array. More...

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

Detailed Description

Dependency Graph Iterator.

Iterate over Dependency Graph (DG) Nodes or Plugs starting at a specified root Node or Plug.

Set and query the root of the iteration.

Set and query the direction (downstream or upstream), traversal priority (depth first or breadth first) and level of detail (Node level or Plug level) and relationship (DG connection, dependency, evaluation graph) of the iteration.

Set and disable a filter to iterate over only specific types (MFn::Type) of Nodes.

Reset the root, filter, direction, traversal priority, relationship and level of detail of the iteration.

Prune branches of the graph from iteration.

In Maya, all geometry, animation and rendering information is implemented in nodes in the Dependency Graph (DG). The DG includes the Directed Acyclic Graph (DAG). Therefore, all DAG nodes are also DG nodes. The data on nodes is associated with Attributes. Attributes on nodes are connected to Attributes on other nodes via plugs on the Attributes. Plugs are, in effect the external intefaces of Attributes.

The DG Iterator Class (MItDependencyGraph) provides methods for iterating over either nodes or plugs, as well as methods for setting and querying the characteristics and behaviour of the iterator.

This iterator will traverse all connected attributes upstream or downstream from the root node of the traversal. For non root nodes, only attributes that are affected by the incoming attribute to that node will be traversed. Hence, only nodes to which data from the root node is flowing will be traversed.

By default, the iterator does not traverse world-space attribute dependencies (an example of a world-space dependency is that translateX affects worldMatrix). The setTraversalOverWorldSpaceDependents method can be used to enable such traversal. Note that even when world-space traversal is enabled, the iterator will only iterate to connected nodes. It does not iterate up and down through the dag hierarchy.

You can set the relationships that the traversal will follow. The default is kDependOn which traverses plug dependencies. The other options are kConnectedTo which traverses node connections and kEvaluationGraph which traverses evaluation graph dependencies.

The DG Iterator is used in conjunction with the Maya Object (MObject), plug (MPlug), Maya Object Array (MObjectArray) and plug Array (MPlugArray) classes.

It is also useful to use Function Sets specific to the nodes returned by the iterator to query and modify the nodes in the DG.

The DG itself can be modified using a DG Modifer (MDGModifier).

Additionally, nodes can be added to and retrieved from selection lists using the Selection List (MSelectionList) class and Selection List Iterator (MItSelectionList). This can be useful for obtaining the root node for an iteration.

Attributes on the nodes can be manipulated using the Attribute Function Set (MFnAttribute) and its derivations.

Examples:: AbcBullet/MayaUtility.cpp, AbcExport/MayaMeshWriter.cpp, AbcExport/MayaUtility.cpp, AbcImport/util.cpp, cgFx/cgfxAttrDef.cpp, cgFx/cgfxShaderNode.cpp, findFileTexturesCmd/findFileTexturesCmd.cpp, findTexturesPerPolygonCmd/findTexturesPerPolygonCmd.cpp, polyRawExporter/polyWriter.cpp, polyX3DExporter/polyWriter.cpp, and skinClusterWeights/skinClusterWeights.cpp.

Member Enumeration Documentation

enum Direction

Direction within the DG relative to root Node or Plug.

Enumerator
kDownstream	From source to destination.
kUpstream	From destination to source.

enum Traversal

Perform a depth first or breadth first traversal.

Enumerator
kDepthFirst	Away from root first.
kBreadthFirst	Equidistant from root first.

enum Level

Level of detail of the iteration.

Enumerator
kNodeLevel	Visit each Node at most once.
kPlugLevel	Visit each Plug at most once.

enum Relationship

What kind of relationship to follow.

Enumerator
kDependsOn	Traverse dependency (this is the default behavior)
kConnectedTo	Traverse DG connection.
kEvaluationGraph	Traverse evaluation graph.

Constructor & Destructor Documentation

MItDependencyGraph	(	MObject &	rootNode,
		MFn::Type	filter = `MFn::kInvalid`,
		Direction	direction = `kDownstream`,
		Traversal	traversal = `kDepthFirst`,
		Level	level = `kNodeLevel`,
		MStatus *	ReturnStatus = `NULL`
	)

Constructor for a DG Iterator with a root node.

If a valid filter is enabled, the iterator automatically advances to the next node after the root node that matches the filter. If no matching node is found the status is failure (MFn::kFailure).

Parameters

[in]	rootNode	Root node
[in]	filter	Object type filter (see MFn::Type)
[in]	direction	Primary direction of iteration
[in]	traversal	Order of traversal
[in]	level	Level of detail of the iteration
[out]	ReturnStatus	Status Code (see below)

Status Codes:

MS::kSuccess Iterator created
MS::kInvalidParameter Invalid parameter passed for direction, traversal, level or relationship - default used
MS::kFailure Could not create iterator

MItDependencyGraph	(	MPlug &	rootPlug,
		MFn::Type	filter = `MFn::kInvalid`,
		Direction	direction = `kDownstream`,
		Traversal	traversal = `kDepthFirst`,
		Level	level = `kPlugLevel`,
		MStatus *	ReturnStatus = `NULL`
	)

Constructor for a DG Iterator with a root plug.

The type of root and the level of the iteration are independent. If a valid filter is enabled, the iterator automatically advances to the next node after the root node that matches the filter. If no matching node is found the status is failure (MFn::kFailure).

Parameters

[in]	rootPlug	Root plug
[in]	filter	Object type filter (see MFn::Type)
[in]	direction	Primary direction of iteration
[in]	traversal	Order of traversal
[in]	level	Level of detail of the iteration
[out]	ReturnStatus	Status Code (see below)

Status Codes:

MS::kSuccess Iterator created
MS::kInvalidParameter Invalid parameter passed for direction, traversal, level or relationship - default used
MS::kFailure Could not create iterator

MItDependencyGraph	(	MObject &	rootNode,
		MPlug &	rootPlug,
		MIteratorType &	infoObject,
		Direction	direction = `kDownstream`,
		Traversal	traversal = `kDepthFirst`,
		Level	level = `kNodeLevel`,
		MStatus *	ReturnStatus = `NULL`
	)

Constructor for a DG Iterator with a root node or a root plug.

If the root node is to be specified, then the root plug will be null. If root plug is non-null, then null should be passed on to root node. The type of root and the level of the iteration are independent. If a valid filter is enabled, the iterator automatically advances to the next node after the root node that matches one of the filter in the filter list, which is specified thro' MIteratorType object. no matching node is found the status is failure (MFn::kFailure).

Parameters

[in]	rootNode	Root node, to which the iterator has to be set to, This can be NULL if we are resetting the root to plug object.
[in]	rootPlug	Root plug, to which the iterator has to be set to, This can be NULL if we are resetting the root to node object.
[in]	infoObject	MIteratorType object, having info about the filter list.
[in]	direction	Primary direction of iteration
[in]	traversal	Order of traversal
[in]	level	Level of detail of the iteration
[out]	ReturnStatus	Status Code (see below)

Status Codes:

MS::kSuccess Iterator created
MS::kInvalidParameter Invalid parameter passed for direction, traversal, or level - default used
MS::kFailure Could not create iterator

OPENMAYA_MAJOR_NAMESPACE_OPEN MItDependencyGraph	(	MObject &	rootNode,
		MFn::Type	filter,
		Direction	direction,
		Traversal	traversal,
		Level	level,
		Relationship	relationship,
		MStatus *	ReturnStatus = `NULL`
	)

Constructor for a DG Iterator with a root node.

If a valid filter is enabled, the iterator automatically advances to the next node after the root node that matches the filter. If no matching node is found the status is failure (MFn::kFailure).

Parameters

[in]	rootNode	Root node
[in]	filter	Object type filter (see MFn::Type)
[in]	direction	Primary direction of iteration
[in]	traversal	Order of traversal
[in]	level	Level of detail of the iteration
[in]	relationship	What kind of relationship to follow
[out]	ReturnStatus	Status Code (see below)

Status Codes:

MS::kSuccess Iterator created
MS::kInvalidParameter Invalid parameter passed for direction, traversal, level or relationship - default used
MS::kFailure Could not create iterator

MItDependencyGraph	(	MPlug &	rootPlug,
		MFn::Type	filter,
		Direction	direction,
		Traversal	traversal,
		Level	level,
		Relationship	relationship,
		MStatus *	ReturnStatus = `NULL`
	)

Constructor for a DG Iterator with a root plug.

The type of root and the level of the iteration are independent. If a valid filter is enabled, the iterator automatically advances to the next node after the root node that matches the filter. If no matching node is found the status is failure (MFn::kFailure).

Parameters

[in]	rootPlug	Root plug
[in]	filter	Object type filter (see MFn::Type)
[in]	direction	Primary direction of iteration
[in]	traversal	Order of traversal
[in]	level	Level of detail of the iteration
[in]	relationship	What kind of relationship to follow
[out]	ReturnStatus	Status Code (see below)

Status Codes:

MS::kSuccess Iterator created
MS::kInvalidParameter Invalid parameter passed for direction, traversal, level or relationship - default used
MS::kFailure Could not create iterator

MItDependencyGraph	(	MObject &	rootNode,
		MPlug &	rootPlug,
		MIteratorType &	infoObject,
		Direction	direction,
		Traversal	traversal,
		Level	level,
		Relationship	relationship,
		MStatus *	ReturnStatus = `NULL`
	)

Constructor for a DG Iterator with a root node or a root plug.

If the root node is to be specified, then the root plug will be null. If root plug is non-null, then null should be passed on to root node. The type of root and the level of the iteration are independent. If a valid filter is enabled, the iterator automatically advances to the next node after the root node that matches one of the filter in the filter list, which is specified thro' MIteratorType object. no matching node is found the status is failure (MFn::kFailure).

Parameters

[in]	rootNode	Root node, to which the iterator has to be set to, This can be NULL if we are resetting the root to plug object.
[in]	rootPlug	Root plug, to which the iterator has to be set to, This can be NULL if we are resetting the root to node object.
[in]	infoObject	MIteratorType object, having info about the filter list.
[in]	direction	Primary direction of iteration
[in]	traversal	Order of traversal
[in]	level	Level of detail of the iteration
[in]	relationship	What kind of relationship to follow
[out]	ReturnStatus	Status Code (see below)

Status Codes:

MS::kSuccess Iterator created
MS::kInvalidParameter Invalid parameter passed for direction, traversal, or level - default used
MS::kFailure Could not create iterator

Member Function Documentation

MStatus reset ( )

Clears iterator data and resets the iterator to the root node or plug.

If a valid filter is enabled, the iterator automatically advances to the next node after the root node that matches the filter. If no matching node is found the status is failure (MFn::kFailure).

Returns: Status Code

Status Codes:

MS::kSuccess Iterator reset
MS::kFailure Iterator not reset - could not access iterator, or iterator does not exist

MStatus resetTo	(	MObject &	rootNode,
		MFn::Type	filter = `MFn::kInvalid`,
		Direction	direction = `kDownstream`,
		Traversal	traversal = `kDepthFirst`,
		Level	level = `kNodeLevel`,
		Relationship	relationship = `kDependsOn`
	)

Clears iterator data and re-initializes the iterator.

If a valid filter is provided, the iterator automatically advances to the next node after the root node that matches the filter. If no matching node is found the status is failure (MFn::kFailure).

Parameters

[in]	rootNode	Root node of the iteration
[in]	filter	Object type filter (see MFn::Type)
[in]	direction	Primary direction of iteration
[in]	traversal	Order of traversal
[in]	level	Level of detail of the iteration
[in]	relationship	What kind of relationship to follow

Returns: Status Code

Status Codes:

MS::kSuccess Iterator created
MS::kInvalidParameter Invalid parameter passed for direction, traversal, or level - default used, or Invalid parameter passed for root node - node does not exist or is not accesible
MS::kFailure Iterator not reset - iterator does not exist or is not accessible

MStatus resetTo	(	MPlug &	rootPlug,
		MFn::Type	filter = `MFn::kInvalid`,
		Direction	direction = `kDownstream`,
		Traversal	traversal = `kDepthFirst`,
		Level	level = `kPlugLevel`,
		Relationship	relationship = `kDependsOn`
	)

Clears iterator data and re-initializes the iterator.

If a valid filter is enabled, the iterator automatically advances to the next node after the root node that matches the filter. If no matching node is found the status is failure (MFn::kFailure).

Parameters

[in]	rootPlug	Root plug of the iteration
[in]	filter	Object type filter (see MFn::Type)
[in]	direction	Primary direction of iteration
[in]	traversal	Order of traversal
[in]	level	Level of detail of the iteration
[in]	relationship	What kind of relationship to follow

Returns: Status Code

Status Codes:

MS::kSuccess Iterator created
MS::kInvalidParameter Invalid parameter passed for direction, traversal, or level - default used, or Invalid parameter passed for root node - node does not exist or is not accesible
MS::kFailure Iterator not reset - iterator does not exist or is not accessible

MStatus resetTo	(	MObject *	rootNode,
		MPlug *	rootPlug,
		MIteratorType &	infoObject,
		Direction	direction = `kDownstream`,
		Traversal	traversal = `kDepthFirst`,
		Level	level = `kPlugLevel`,
		Relationship	relationship = `kDependsOn`
	)

Clears iterator data and re-initializes the iterator.

The filter list is reset to the new list specified thro' MIteratorType object. If a valid filter is enabled, the iterator automatically advances to the next node after the root node/plug that matches the filter. If no matching node is found the status is failure (MFn::kFailure).

Parameters

[in]	rootNode	Root Node of the iteration. This can be null if the root has to be reset to plug.
[in]	rootPlug	Root plug of the iteration. This can be null if the root has to be reset to node.
[in]	infoObject	MIteratorType Object which has info about the filter list and the object type, the root will be reset to.
[in]	direction	Primary direction of iteration
[in]	traversal	Order of traversal
[in]	level	Level of detail of the iteration
[in]	relationship	What kind of relationship to follow

Returns: Status Code

Status Codes:

MS::kSuccess Iterator created
MS::kInvalidParameter Invalid parameter passed for direction, traversal, or level - default used, or Invalid parameter passed for root node - node does not exist or is not accesible
MS::kFailure Iterator not reset - iterator does not exist or is not accessible

MObject rootNode ( MStatus * ReturnStatus = NULL )

Retrieves the root node of the iteration.

Parameters

[out] ReturnStatus Status Code (see below)

Returns: The root node

Status Codes:

MS::kSuccess Root node is valid
MS::kFailure Root node not retrieved - iterator does not exist or is not accessible, or root node does not exist or is not accessible

MPlug rootPlug ( MStatus * ReturnStatus = NULL )

Retrieves the root plug of the iteration.

Parameters

[out] ReturnStatus Status Code (see below)

Returns: The root plug

Status Codes:

MS::kSuccess Root plug is valid
MS::kFailure Root plug not retrieved - iterator does not exist or is not accessible, or root plug does not exist or is not accessible

MFn::Type currentFilter ( MStatus * ReturnStatus = NULL )

Retrieves the current node type filter.

Parameters

[out] ReturnStatus Status Code (see below)

Returns: The current node type filter

Status Codes:

MS::kSuccess Filter is valid
MS::kFailure Filter status not known - iterator does not exist or is not accessible

MStatus setCurrentFilter ( MFn::Type filter = MFn::kInvalid )

Sets the node or plug filter.

Plug filtering is based on the type of the corresponding Attribute. Defaults to disabled (MFn::kInvalid). If a valid filter is specified, the iterator automatically advances to the next node that matches the filter. If no matching node status is failure (MFn::kFailure).

Disables pruning on the new filter (default). Use enablePruningOnFilter() method to enable pruning. No other iterator data is changed. If new filter is the same as current filter, no action is taken.

Parameters

[in] filter node or Attribute type filter (see MFn::Type)

Returns: Status Code

Status Codes:

MS::kSuccess Filter is set
MS::kInvalidParameter Speicified filter the same as current filter
MS::kFailure Filter not set - iterator does not exist or is not accessible

MStatus resetFilter ( )

Resets the node or plug filter to default, MFn::kInvalid (filter disabled).

Disables pruning on the filter (default). Resets the iterator.

Returns: Status Code

Status Codes:

MS::kSuccess Filter is reset
MS::kFailure Filter not reset - iterator does not exist or is not accessible

bool isPruningOnFilter ( MStatus * ReturnStatus = NULL )

Tests whether or not the iteration path is pruned automatically at nodes or plugs which do not match the filter.

Parameters

[in] ReturnStatus Status Code (see below)

Returns: Bool: true if pruning is enabled, false otherwise.

Status Codes:

MS::kSuccess State is valid
MS::kFailure Pruning state not known (default returned) - iterator does not exist or is not accessible

MStatus enablePruningOnFilter ( )

Enables automatic pruning of iteration path at nodes or plugs which do not match the filter.

Returns: Status Code

Status Codes:

MS::kSuccess Pruning enabled
MS::kFailure Pruning state not known - iterator does not exist or is not accessible

MStatus disablePruningOnFilter ( )

Disables automatic pruning of iteration path at nodes or plugs which do not match the filter.

Returns: Status Code

Status Codes:

MS::kSuccess Pruning disabled
MS::kFailure Pruning state not known - iterator does not exist or is not accessible

Examples:: findFileTexturesCmd/findFileTexturesCmd.cpp.

bool isDirectionDownStream ( MStatus * ReturnStatus = NULL )

Tests whether or not the iteration is moving downstream (in the direction of data flow) in the DG.

Parameters

[out] ReturnStatus Status Code (see below)

Returns

true Direction is downstream (MItDependencyGraph::kDownstream)
false Direction is upstream (MItDependencyGraph::kUpstream)

Status Codes:

MS::kSuccess Direction is valid
MS::kFailure Direction not known (default returned) - iterator does not exist or is not accessible

MItDependencyGraph::Direction currentDirection ( MStatus * ReturnStatus = NULL )

Reports the direction of the iteration through the graph.

Parameters

[out] ReturnStatus Status Code (see below)

Returns

MItDependencyGraph::kDownstream Direction is downstream
MItDependencyGraph::kDownstream Direction is upstream

Status Codes:

MS::kSuccess Direction is valid
MS::kFailure Direction not known (default returned) - iterator does not exist or is not accessible

MStatus toggleDirection ( )

Toggles the direction of the iteration.

Resets the root of the iteration to the current node or plug depending on the level of iteration. Clears iterator path data. If a valid filter is enabled, the iterator automatically advances to the next node that matches the filter. If no matching node is found the status is failure (MFn::kFailure). No other iterator parameters are affected.

Returns: Status Code

Status Codes:

MS::kSuccess Direction toggled
MS::kFailure Direction not toggled - iterator does not exist or is not accessible

bool isTraversalDepthFirst ( MStatus * ReturnStatus = NULL )

Tests whether or not the iteration is proceeding depth first (away from the root of the iteration) in the DG.

Parameters

[out] ReturnStatus Status Code (see below)

Returns

true Traversal is depth first (MItDependencyGraph::kDepthFirst)
false Traversal is breadth first (MItDependencyGraph::kBreadthFirst)

Status Codes:

MS::kSuccess Traversal is valid
MS::kFailure Traversal not known (default returned) - iterator does not exist or is not accessible

MItDependencyGraph::Traversal currentTraversal ( MStatus * ReturnStatus = NULL )

Reports the traversal mode of the iteration through the graph.

Parameters

[out] ReturnStatus Status Code (see below)

Returns

MItDependencyGraph::kDepthFirst Traversal is depth first
MItDependencyGraph::kBreadthFirst Traversal is breadth first

Status Codes:

MS::kSuccess Traversal is valid
MS::kFailure Traversal not known (default returned) - iterator does not exist or is not accessible

MStatus toggleTraversal ( )

Toggles the traversal of the iteration.

Resets the root of the iteration to the current node or plug depending on the level of iteration. Clears iterator path data. If a valid filter is enabled, the iterator automatically advances to the next node that matches the filter. If no matching node is found the status is failure (MFn::kFailure). No other iterator parameters are affected.

Returns: Status Code

Status Codes:

MS::kSuccess Traversal toggled
MS::kFailure Traversal not toggled - iterator does not exist or is not accessible

bool atNodeLevel ( MStatus * ReturnStatus = NULL )

Tests whether or not the iteration is at the node level of detail (every node is visited only once) in the DG.

Parameters

[out] ReturnStatus Status Code (see below)

Returns

true node level (MItDependencyGraph::kNodeLevel)
false plug level (MItDependencyGraph::kPlugLevel)

Status Codes:

MS::kSuccess Level is valid
MS::kFailure Level not known (default returned) - iterator does not exist or is not accessible

MItDependencyGraph::Level currentLevel ( MStatus * ReturnStatus = NULL )

Reports the level of the iteration through the graph.

Parameters

[out] ReturnStatus Status Code (see below)

Returns

MItDependencyGraph::kNodeLevel Level is node level
MItDependencyGraph::kPlugLevel Level is plug level

Status Codes:

MS::kSuccess Level is valid
MS::kFailure Level not known (default returned) - iterator does not exist or is not accessible

MItDependencyGraph::Relationship currentRelationship ( MStatus * ReturnStatus = NULL )

Reports the relationship mode of the iteration through the graph.

Parameters

[out] ReturnStatus Status Code (see below)

Returns

MItDependencyGraph::kDependsOn Follow dependency
MItDependencyGraph::kConnectedTo Follow DG connection
MItDependencyGraph::kEvaluationGraph Follow evaluation graph

Status Codes:

MS::kSuccess Traversal is valid
MS::kFailure Traversal not known (default returned) - iterator does not exist or is not accessible

MStatus setCurrentRelationship ( Relationship relationship )

Sets the relationship mode of the iteration.

Resets the root of the iteration to the current node or plug depending on the level of iteration. Clears iterator path data. If a valid filter is enabled, the iterator automatically advances to the next node that matches the filter. If no matching node is found the status is failure (MFn::kFailure). No other iterator parameters are affected.

Returns: Status Code

Status Codes:

MS::kSuccess Traversal toggled
MS::kFailure Traversal not toggled - iterator does not exist or is not accessible

MStatus setTraversalOverWorldSpaceDependents ( bool val )

This method controls whether the iterator will include world-space attribute dependencies in its traversal.

For example, say there is an animation curve attached to the translateX attribute on a transform, and an upstream iterator starts at the worldMatrix attribute. If world-space traversal is enabled, the iterator will get to the animation curve. Note however that even when world-space traversal is enabled, the iterator will only iterate to connected nodes. It does not iterate up and down through the dag hierarchy.

By default, traversal of world-space dependencies is disabled.

Parameters

[in] val True to enable traversal of world-space dependencies, false to disable.

Returns: Status Code

Status Codes:

MS::kSuccess Traversal state was set.
MS::kFailure Iterator does not exist or is not accessible.

bool isTraversingOverWorldSpaceDependents ( MStatus * ReturnStatus = NULL )

Tests whether the iterator is set to traverse world-space attribute dependencies.

Parameters

[out] ReturnStatus Status Code (see below)

Returns

true Traversing of world-space attributes is enabled.
false Traversing of world-space attributes is disabled.

Status Codes:

MS::kSuccess Traversal state was successfully returned.
MS::kFailure Iterator does not exist or is not accessible.

MStatus toggleLevel ( )

Toggles the level of the iteration.

Resets the root of the iteration to the current node or plug depending on the level of iteration. Clears iterator path data. If a valid filter is enabled, the iterator automatically advances to the next node that matches the filter. If no matching node is found the status is failure (MFn::kFailure). No other iterator parameters are affected.

Returns: Status Code

Status Codes:

MS::kSuccess Level toggled
MS::kFailure Level not toggled - iterator does not exist or is not accessible

MStatus next ( )

Iterates to the next node or plug in accordance with the direction, traversal, level and filter.

If a valid filter is set, the iterator only visits those nodes that match the filter. When filtering is enabled nodes that have unknown type are treated as non-matching nodes. With filtering disabled, iteration to a node with an unknown type is treated as a failure. An attempt to iterate when there is nothing left to iterate over has no effect.

Returns: Status Code

Status Codes:

MS::kSuccess Iteration successful, or the iteration was already complete (i.e. isDone() was already true), or nothing left to iterate over.
MS::kFailure Could not iterate - iterator does not exist or is not accessible, or node has unrecognized type, or Attribute of plug is inaccessible, or could not update plug path length.

Examples:: findFileTexturesCmd/findFileTexturesCmd.cpp.

bool isDone ( MStatus * ReturnStatus = NULL )

Indicates whether or not all nodes or plugs have been iterated over in accordance with the direction, traversal, level and filter.

If a valid filter is set, the iterator only visits those nodes that match the filter.

Parameters

[out] ReturnStatus Status Code (see below)

Returns

true Iteration is done
false Iteration is not done

Status Codes:

MS::kSuccess Return valid
MS::kFailure Return not valid - iterator does not exist or is not accessible

Examples:: cgFx/cgfxAttrDef.cpp, cgFx/cgfxShaderNode.cpp, and findFileTexturesCmd/findFileTexturesCmd.cpp.

MStatus prune ( )

Prunes the search path at the current plug.

Iterator will not visit any of the plugs connected to the pruned plug.

Returns: Status Code

Status Codes:

MS::kSuccess Path pruned.
MS::kFailure Could not prune path - iterator does not exist or is not accessible, or iteration is done

MObject thisNode ( MStatus * ReturnStatus = NULL )

This method is obsolete.

Retrieves the current node of the iteration.

[as of Maya 2019]

Deprecated:: Use MItDependencyGraph::currentItem instead.

Results in a null object on failure or if the node is of a unrecognized type.

Parameters

[out] ReturnStatus Status Code (see below)

Returns: Current node

Status Codes:

MS::kSuccess node is valid
MS::kFailure node not retrieved. Iterator does not exist or is not accessible, or node does not exist or is not accessible, or node type is not recognized, or iteration is done (null Object returned)

MObject currentItem ( MStatus * ReturnStatus = NULL )

Retrieves the current node of the iteration.

Results in a null object on failure or if the node is of a unrecognized type.

Parameters

[out] ReturnStatus Status Code (see below)

Returns: Current node

Status Codes:

MS::kSuccess node is valid
MS::kFailure node not retrieved - iterator does not exist or is not accessible, or node does not exist or is not accessible, or node type is not recognized, or iteration is done (null Object returned)

Examples:: findFileTexturesCmd/findFileTexturesCmd.cpp.

bool thisNodeHasUnknownType ( MStatus * ReturnStatus = NULL )

Indicates whether or not the current node has an unrecognised type.

This is useful if an unexpected failure is encountered in the next() or currentItem() methods.

Returns true only if node exists but is not a recognizable type.

Returns false if node exists and is recognizable. Also returns false on failure or if the iteration is done.

Parameters

[out] ReturnStatus Status Code (see below)

Returns

true Unknown type
false Type is known or iterator is done or failure encountered

Status Codes:

MS::kSuccess Return valid
MS::kFailure Return not valid - iterator does not exist or is not accessible, or node does not exist or is not accessible

MPlug thisPlug ( MStatus * ReturnStatus = NULL )

Retrieves the current plug of the iteration.

Results in a null plug on failure.

Parameters

[out] ReturnStatus Status Code (see below)

Returns: Current plug

Status Codes:

MS::kSuccess plug is valid
MS::kFailure plug not retrieved - the iteration is done, iterator does not exist or is not accessible, or plug does not exist or is not accessible (null plug returned)

MPlug previousPlug ( MStatus * ReturnStatus = NULL )

Retrieves the previous plug of the iteration.

Results in a null plug on failure. Null plug may also indicate that the current plug is the root plug.

Parameters

[out] ReturnStatus Status Code (see below)

Returns

Current plug

Status Codes:

MS::kSuccess plug is valid
MS::kFailure plug not retrieved - iterator does not exist or is not accessible, plug does not exist or is not accessible, or current plug may be root plug (null plug returned)

MStatus getNodesVisited ( MObjectArray & nodes ) const

Retrieves all nodes visited during the iteration.

State of the provided array is undefined if this method fails.

Parameters

[out] nodes Target array for retrieved nodes. On success contains all nodes visited

Returns: Status Code

Status Codes:

MS::kSuccess
MS::kFailure Could not retrieve nodes - iterator does not exist or is not accessible, or list of nodes does not exist or is not accessible;

MStatus getPlugsVisited ( MPlugArray & plugs ) const

Retrieves all plugs visited during the iteration.

State of the provided array is undefined if this method fails.

Parameters

[out] plugs Target array for retrieved plugs. On success contains all plugs visited

Returns: Status Code

Status Codes:

MS::kSuccess
MS::kFailure Could not retrieve plugs - iterator does not exist or is not accessible, or list of plugs does not exist or is not accessible;

MStatus getNodePath ( MObjectArray & path ) const

Retrieves the direct path from the current node to the root node.

Path does not include the current node. State of the provided array is undefined if this method fails.

Parameters

[out] path Target array for retrieved path. On success contains direct path from the current node to the root node

Returns: Status Code

Status Codes:

MS::kSuccess
MS::kFailure Could not retrieve path - iterator does not exist or is not accessible, or path does not exist or is not accessible;

Examples:: findFileTexturesCmd/findFileTexturesCmd.cpp.

MStatus getPlugPath ( MPlugArray & path ) const

Retrieves the direct path from the current plug to the root plug, with the current plug in element 0 of the array and the root plug in the final element of the array.

Once the iterator is done (i.e. isDone() returns true) there is no longer a current plug and this method will return an empty array.

If this method fails the state of the returned array is undefined.

Parameters

[out] path Target array for retrieved path. On success contains direct path from the current plug to the root plug

Returns: Status Code

Status Codes:

MS::kSuccess
MS::kFailure Could not retrieve path - iterator does not exist or is not accessible, or path does not exist or is not accessible;

const char * className ( )

static

Returns the name of this class.

Returns: The name of this class.

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

MItDependencyGraph.h
MItDependencyGraph.cpp

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation