MFnCharacter Class Reference

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Detailed Description

Function Set for Characters.

Maya offers "character" nodes to simplify the setting of keyframes on collections of attributes. The implementation of the "character" is a sub-class of MFnSet taking advantage of the fact that attributes can be represented as MObjects and can be made members of a set. The fact that sets also derive from MObject means that characters may have other character sets as members thus establishing a hierarchy. Only attributes and characters can be members of a character set. The character node will disallow the addition of other objects to its set.

Character sets are also part of a partition, meaning that membership of character sets cannot overlap with other character sets. Thus, when an attribute already in a character is added to another character it must be removed from the original character.

Characters are integral to Maya's nonlinear animation system, "Trax". Trax allows the user to create "animation clips", which bundle a set of animation curves so that they can be reused multiple times, with different timing then the original clip. When a clip is created, Maya finds the the animation curves that are attached to the attributes in the character set and moves those animation curves into the newly created clip. The MFnClip function set is the Maya function set for clips.

Clips in maya can be of two types: source clips and scheduled clips. In the Maya UI, source clips are visible in the Visor while scheduled clips are visible in Trax. A source clip contains the animation curves for the clip. An scheduled clip contains data about the placement of an instance of a source clip in the Maya timeline. In this context, an "instance" means that the animation curves from the source clip are shared by the scheduled clip. Scheduled clips never contain their own animation curves, they always refer to a source clip's curves.

For example, if you create a clip called "run" in maya that lasts from frames 1-20, a source clip node will be created with a start of 1, a duration of 19, and dependency graph connections to all of the animation curves that make up the "run". If you then place an instance of the run clip at frame 5 and another instance of the run clip at frame 20, you have 2 scheduled clips: one with a start frame of 5 and one with a start frame of 20. As mentioned in the previous paragraph, only a single set of animation curves exist for the run regardless of the number of times the run is scheduled.

Trax also allows you to create "blends" between clips, which enable you to control the transition between the clips. A blend is represented in the dependency graph by an "animBlendInOut" node, which uses an animation curve to determine the transition type.

In the dependency graph, when a character has animation clips, the character node will always be connected to a "clipLibrary" node and a "clipScheduler" node. The clipLibrary node is connected to all of the source clips and their animation curves. The clipScheduler node is connected to the scheduled clips and blends. It is the clipScheduler that computes the final animation by looking at the placement and overlap of the clips and feeding the attribute data back into the character set.

Examples:

createClipCmd.cpp.

#include <MFnCharacter.h>

Inheritance diagram for MFnCharacter:

List of all members.

Public Member Functions
virtual MFn::Type	type () const
	Function set type.
virtual	~MFnCharacter ()
	Destructor.
	MFnCharacter ()
	Default constructor.
	MFnCharacter (MObject &object, MStatus *ReturnStatus=NULL)
	Constructor.
MStatus	attachSourceToCharacter (MObject &sourceClip, MDGModifier &dgMod)
	Attaches a given source clip node (created using MFnClip::createSourceClip) to the character's clipLibrary.
MStatus	attachInstanceToCharacter (MObject &instanceClip, MDGModifier &dgMod)
	Attaches an instance of a clip to the character.
MStatus	addCurveToClip (MObject &curve, MObject &sourceClip, MPlug &characterPlug, MDGModifier &dgMod)
	Adds an animation curve to a clip.
MObject	createBlend (MObject &instancedClip1, MObject &instancedClip2, MObject &blendAnimCurve, MDGModifier &dgMod, MStatus *ReturnStatus=NULL)
	Creates a blend between two instanced clips on the character.
bool	blendExists (MObject &instancedClip1, MObject &instancedClip2, MObject &blendResult)
	Return true if a blend exists between the two instanced clips on the character.
bool	removeBlend (MObject &instancedClip1, MObject &instancedClip2, MDGModifier &dgMod, MStatus *ReturnStatus=NULL)
	Remove the blend between the two instanced clips on the character.
bool	getCharacterThatOwnsPlug (MPlug &plug, MObject &result) const
	Given a plug, test the plug to see if it is owned by a character.
MStatus	getMemberPlugs (MPlugArray &result) const
	Get the members of the character set that are attributes.
MStatus	getSubCharacters (MSelectionList &result) const
	Get a list of the subcharacters that are members of the character set.
MObject	getClipScheduler (MStatus *ReturnStatus=NULL)
	Get the clipScheduler node that manages the playback of clips on this character.
int	getScheduledClipCount (MStatus *ReturnStatus=NULL)
	Return the number of clips that have been scheduled on this character.
MObject	getScheduledClip (int index, MStatus *ReturnStatus=NULL)
	Return the scheduled animClip node corresponding to the specified index.
int	getSourceClipCount (MStatus *ReturnStatus=NULL)
	Return the number of source clips managed by the clipLibrary node of this character.
MObject	getSourceClip (int index, MStatus *ReturnStatus=NULL)
	Return the animClip node corresponding to the specified index.
int	getBlendCount (MStatus *ReturnStatus=NULL)
	Return the number of blends that have been added to clips on this character.
MObject	getBlend (int index, MStatus *ReturnStatus=NULL)
	Return the animBlendInOut node corresponding to the specified index.
MStatus	getBlendClips (int index, MObject &clip1, MObject &clip2)
	Returns the clip nodes that are blended by the blend node corresponding to the specified index.
	MFnCharacter (const MObject &object, MStatus *ReturnStatus=NULL)
	Constructor.
Protected Member Functions
virtual const char *	className () const
	Class name.

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Constructor & Destructor Documentation

MFnCharacter	(	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

MFnCharacter	(	const 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

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Member Function Documentation

MFn::Type type

(

)

const [virtual]

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Function set type.

Return the class type : MFn::kCharacter.

Reimplemented from MFnSet.

const char * className

(

)

const [protected, virtual]

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Class name.

Return the class name : "MFnCharacter".

Reimplemented from MFnSet.

MStatus attachSourceToCharacter	(	MObject &	sourceClip,
		MDGModifier &	dgMod
	)

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Attaches a given source clip node (created using MFnClip::createSourceClip) to the character's clipLibrary.

Attaches a clipLibrary and clipScheduler to the character if they are not attached already.

Parameters:

[in]	sourceClip	source clip to be attached
[in]	dgMod	command modifier used for undo and redo

Returns:

The return status

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure operation failed
• MS::kInsufficientMemory out of memory

Examples:

createClipCmd.cpp.

MStatus attachInstanceToCharacter	(	MObject &	instanceClip,
		MDGModifier &	dgMod
	)

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Attaches an instance of a clip to the character.

If the source clip related to the clip instance is not already attached to the character, it will be attached as well.

This command will fail if the instanced clip passed in is not associated with a source clip. The best way to associate an instanced clip with a source clip is to create the instanced clip using MFnClip::createInstancedClip.

Parameters:

[in]	instanceClip	the animClip node representing the clipInstance
[in]	dgMod	command modifier used for undo and redo

Returns:

The return status

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure operation failed
• MS::kInsufficientMemory out of memory

Examples:

createClipCmd.cpp.

MStatus addCurveToClip	(	MObject &	curve,
		MObject &	sourceClip,
		MPlug &	plug,
		MDGModifier &	dgMod
	)

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Adds an animation curve to a clip.

The user must provide the animation curve, and the related source clip node (typically created using MFnCharacter::createSourceClip). The user must also specify the plug that the clip will drive. The plug must be a member of the character managed by this MFnCharacter.

Parameters:

[in]	curve	the animation curve to be added to the clip
[in]	sourceClip	a source clip specifying the start and duratiohn of the clip
[in]	plug	plug that this animCurve will drive
[in]	dgMod	command modifier used for undo and redo

Returns:

The return status

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure operation failed
• MS::kInsufficientMemory out of memory

Examples:

createClipCmd.cpp.

MObject createBlend	(	MObject &	instancedClip1,
		MObject &	instancedClip2,
		MObject &	blendAnimCurve,
		MDGModifier &	dgMod,
		MStatus *	ReturnStatus = NULL
	)

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Creates a blend between two instanced clips on the character.

The blend is defined by a specified paramCurve, which should be keyed between times of 0 and 1. Time 0 corresponds to the start time of the blend. Time 1 corresponds to the end time of the blend. The blend will be performed on the clips according to the keyed value of the blend curve, using the equation: (value)*clip1 + (1-value)*clip2. For example, let's say the blend curve goes from a value of (0,0) to (1,1). At the start of the blend you will have 100% of clip1, and 0% of clip2. At the end of the blend you will have 0% of clip1, and 100% of clip2.

Parameters:

[in]	instancedClip1	clip to be blended
[in]	instancedClip2	another clip to be blended
[in]	blendAnimCurve	animCurve defining the type of the blend
[in]	dgMod	command modifier used for undo and redo
[out]	ReturnStatus	return status

Returns:

The resulting animBlend node

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure operation failed
• MS::kInsufficientMemory out of memory

bool blendExists	(	MObject &	instancedClip1,
		MObject &	instancedClip2,
		MObject &	blendResult
	)

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Return true if a blend exists between the two instanced clips on the character.

If a blend exists, the animBlend node related to the blend is also returned.

Parameters:

[in]	instancedClip1	clip
[in]	instancedClip2	another clip
[in]	blendResult	the blend, if a blend is found

Returns:

true, if a blend was found between the two clips

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure operation failed
• MS::kInsufficientMemory out of memory

bool removeBlend	(	MObject &	instancedClip1,
		MObject &	instancedClip2,
		MDGModifier &	dgMod,
		MStatus *	ReturnStatus = NULL
	)

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Remove the blend between the two instanced clips on the character.

If a blend exists and was deleted, returns true. If a blend did not exist, returns false.

Parameters:

[in]	instancedClip1	clip
[in]	instancedClip2	another clip
[in]	dgMod	command modifier used for undo and redo
[out]	ReturnStatus	the return status

Returns:

true, if a blend was found and deleted

bool getCharacterThatOwnsPlug	(	MPlug &	plug,
		MObject &	result
	)		const

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Given a plug, test the plug to see if it is owned by a character.

If a character controls this plug, the character will be returned

Parameters:

[in]	plug	MPlug containing a plug for which you want to find the related character
[in]	result	Mobject containing a character if the plug is in a character, else an empty MObject

Returns:

true, if the plug is in a character

MStatus getMemberPlugs

(

MPlugArray &

result

)

const

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Get the members of the character set that are attributes.

Return them as a plug array. A character set can contain only attributes and subcharacters. To get all of the members of the character, use MFnSet::getMembers. To get the subcharacters, use MFnCharacter::getSubcharacters.

Parameters:

[out]

result

storage for the returned list of members

Returns:

Return status

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure this function set does not have a valid character object
• MS::kInsufficientMemory out of memory

Examples:

createClipCmd.cpp.

MStatus getSubCharacters

(

MSelectionList &

result

)

const

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Get a list of the subcharacters that are members of the character set.

Parameters:

[out]

result

storage for the returned list of members

Returns:

Return status

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure this function set does not have a valid character object
• MS::kInsufficientMemory out of memory

MObject getClipScheduler

(

MStatus *

ReturnStatus = NULL

)

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Get the clipScheduler node that manages the playback of clips on this character.

If no clips have been created for this character, this method will return an empty MObject.

Parameters:

[out]

ReturnStatus

return status

Returns:

MObject containing a clipScheduler node

Status Codes:

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

int getScheduledClipCount

(

MStatus *

ReturnStatus = NULL

)

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Return the number of clips that have been scheduled on this character.

Parameters:

[out]

ReturnStatus

return status

Returns:

Number of clips scheduled on this character

Status Codes:

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

MObject getScheduledClip	(	int	index,
		MStatus *	ReturnStatus = NULL
	)

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Return the scheduled animClip node corresponding to the specified index.

The specified index should range from 0 to clipCount-1 where clipCount is the value returned by MFnCharacter::getScheduledClipCount.

Parameters:

[in]	index	Clip index.
[out]	ReturnStatus	return status

Returns:

MObject containing an animClip node

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure this function set does not have a valid character object
• MS::kIndexOutOfRange this index given exceeded the total clip count
• MS::kObjectDoesNotExist the clip node for this index does not exist, indicates a missing connection in the dependency graph

int getSourceClipCount

(

MStatus *

ReturnStatus = NULL

)

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Return the number of source clips managed by the clipLibrary node of this character.

For more information on source clips, refer to the description of the MFnCharacter node.

Parameters:

[out]

ReturnStatus

return status

Returns:

Number of source clips owned by the library on this character

Status Codes:

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

MObject getSourceClip	(	int	index,
		MStatus *	ReturnStatus = NULL
	)

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Return the animClip node corresponding to the specified index.

The animClip node will be a source clip node. The specified index should range from 0 to clipCount-1 where clipCount is the value returned by MFnCharacter::getSourceClipCount.

Parameters:

[in]	index	Clip index.
[out]	ReturnStatus	Return status.

Returns:

MObject containing an animClip node

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure this function set does not have a valid character object
• MS::kIndexOutOfRange this index given exceeded the total clip count
• MS::kObjectDoesNotExist the clip node for this index does not exist, indicates a missing connection in the dependency graph

int getBlendCount

(

MStatus *

ReturnStatus = NULL

)

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Return the number of blends that have been added to clips on this character.

Parameters:

[out]

ReturnStatus

return status

Returns:

Number of blends on clips in this character

Status Codes:

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

MObject getBlend	(	int	index,
		MStatus *	ReturnStatus = NULL
	)

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Return the animBlendInOut node corresponding to the specified index.

Parameters:

[in]	index	Index of the desired node.
[out]	ReturnStatus	return status

Returns:

MObject containing an animBlendInOut node

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure this function set does not have a valid character object
• MS::kIndexOutOfRange this index given exceeded the total blend count
• MS::kObjectDoesNotExist the blend node for this index does not exist, indicates a missing connection in the dependency graph or that no blend exists

MStatus getBlendClips	(	int	index,
		MObject &	clip1,
		MObject &	clip2
	)

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Returns the clip nodes that are blended by the blend node corresponding to the specified index.

Parameters:

[in]	index	the index of the blend
[out]	clip1	the first of the clips being blended
[out]	clip2	the second of the clips being blended

Returns:

Return status

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure this function set does not have a valid character object
• MS::kIndexOutOfRange this index given exceeded the total blend count
• MS::kObjectDoesNotExist the clip nodes for this index do not exist, indicates a missing connection in the dependency graph or an invalid blend