MFnClip Class Reference
[OpenMayaAnim - API module for animationFunctionSet classes]

#include <MFnClip.h>

Inheritance diagram for MFnClip:

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Collaboration diagram for MFnClip:

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List of all members.


Detailed Description

clip function set

Maya uses animation clips as the building block of its nonlinear animation system, "Trax". An animation clip allows the user to bundle a set of animation curves independent of time so that they can be reused multiple times, with different timing then the original clip.

Character sets (MFnCharacter) are integral to Maya's clip architecture, since a clip contains whatever attributes of the character were animated when the clip was created. For more information on character sets, refer to the MFnCharacter documentation.

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. A 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.

To create a source clip, the typical steps are:

  1. If the attributes are not already in a character, create a character containing the attributes.
  2. Create a source clip using MFnClip::createSourceClip
  3. Attach the clip to a character using MFnCharacter::attachSourceToCharacter
  4. Attach animation curves to the clip using MFnCharacter::addCurveToClip

To create a scheduled clip so that it appears in the Trax Editor, the typical steps are:

  1. Create an instanced animClip node using MFnClip::createInstancedClip, and associate it with the source clip that you want to instance.
  2. Attach the clip instance to the character using MFnCharacter::attachInstanceToCharacter
Examples:

createClipCmd.cpp.


Public Member Functions

virtual MFn::Type type () const
 Function set type.
virtual ~MFnClip ()
 Destructor.
 MFnClip ()
 Default constructor.
 MFnClip (MObject &object, MStatus *ReturnStatus=NULL)
 Constructor.
MObject createSourceClip (const MTime &sourceStart, const MTime &sourceDuration, MDGModifier &dgMod, MStatus *ReturnStatus=NULL)
MObject createInstancedClip (MObject &sourceClip, const MTime &start, MDGModifier &dgMod, MStatus *ReturnStatus=NULL, bool absolute=1, double postCycle=0.0, double weight=1.0, double scale=1.0, double preCycle=0.0)
bool isInstancedClip (MStatus *ReturnStatus=NULL)
bool isPose (MStatus *ReturnStatus=NULL)
MObject sourceClip (MStatus *ReturnStatus=NULL)
double getPreCycle (MStatus *ReturnStatus=NULL)
double getPostCycle (MStatus *ReturnStatus=NULL)
double getCycle (MStatus *ReturnStatus=NULL)
 This method is obsolete.
double getWeight (MStatus *ReturnStatus=NULL)
double getScale (MStatus *ReturnStatus=NULL)
bool getAbsolute (MStatus *ReturnStatus=NULL)
 This method is obsolete.
bool getEnabled (MStatus *ReturnStatus=NULL)
MTime getStartFrame (MStatus *ReturnStatus=NULL)
MTime getSourceStart (MStatus *ReturnStatus=NULL)
MTime getSourceDuration (MStatus *ReturnStatus=NULL)
MStatus getMemberAnimCurves (MObjectArray &curves, MPlugArray &associatedAttrs)
MStatus getAbsoluteChannelSettings (MIntArray &absoluteChannels)
int getTrack (MStatus *ReturnStatus=NULL)
MStatus setPoseClip (bool state, MDGModifier *mod=NULL)
MStatus setPreCycle (double cycle, MDGModifier *mod=NULL)
MStatus setPostCycle (double cycle, MDGModifier *mod=NULL)
MStatus setCycle (double cycle, MDGModifier *mod=NULL)
 This method is obsolete.
MStatus setWeight (double wt, MDGModifier *mod=NULL)
MStatus setScale (double scale, MDGModifier *mod=NULL)
MStatus setAbsolute (bool abs, MDGModifier *mod=NULL)
 This method is obsolete.
MStatus setEnabled (bool val, MDGModifier *mod=NULL)
MStatus setStartFrame (const MTime &start, MDGModifier *mod=NULL)
MStatus setSourceData (const MTime &start, const MTime &duration, MDGModifier *mod=NULL)
MStatus setTrack (int index, MDGModifier *mod=NULL)
MStatus setAbsoluteChannelSettings (const MIntArray &absoluteChannels, MDGModifier *mod=NULL)
 MFnClip (const MObject &object, MStatus *ReturnStatus=NULL)
 Constructor.

Protected Member Functions

virtual const char * className () const
 Class name.

Constructor & Destructor Documentation

MFnClip::MFnClip ( 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:

MFnClip::MFnClip ( 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:


Member Function Documentation

MFn::Type MFnClip::type (  )  const [virtual]

Function set type.

Return the class type : MFn::kClip

Reimplemented from MFnDependencyNode.

const char * MFnClip::className (  )  const [protected, virtual]

Class name.

Return the class name : "MFnClip"

Reimplemented from MFnDependencyNode.

MObject MFnClip::createSourceClip ( const MTime sourceStart,
const MTime sourceDuration,
MDGModifier dgMod,
MStatus ReturnStatus = NULL 
)

Creates a source clip node and associates it with this function set. Each animation clip has a single source clip, which defines the startFrame and duration of the clip's animation curves. The startFrame and duration act as a window onto the animation curves, defining the range of animation that is considered part of the clip. After a source clip node is created, it can be passed to a MFnCharacter along with the clip animCurves in order to associate the clip with the character.

Parameters:
[in] sourceStart time on clip animCurves that represents clip start
[in] sourceDuration time extent of the clip
[in] dgMod command modifier used for undo and redo
[out] ReturnStatus return status
Returns:
The newly created clip.
Status Codes:
Examples:

MObject MFnClip::createInstancedClip ( MObject sourceClip,
const MTime start,
MDGModifier dgMod,
MStatus ReturnStatus = NULL,
bool  absolute = 1,
double  postCycle = 0.0,
double  weight = 1.0,
double  scale = 1.0,
double  preCycle = 0.0 
)

Creates an instance of a clip that will be viewable in the Trax editor.

Parameters:
[in] sourceClip the source clip node
[in] start start frame where the instance will be scheduled
[in] dgMod command modifier used for undo and redo
[in] ReturnStatus return status
[in] absolute whether the clip is absolute (1) or relative (0)
[in] preCycle pre cycle for the clip
[in] postCycle post cycle for the clip
[in] weight weight for the clip
[in] scale scale for the clip
Returns:
The newly created clip.
Status Codes:
Examples:

bool MFnClip::isInstancedClip ( MStatus ReturnStatus = NULL  ) 

Return true or false as to whether the clip node represents the source clip or an instanced clip. All clips maintained by the clipScheduler node and visible in the TraX editor are instanced clips. All clips maintained by the clipLibrary node and visible in the Visor are non-instanced clips, also called "Source Clips". Each instanced clip has a corresponding source clip.

Parameters:
[out] ReturnStatus return status
Returns:
True or false as to whether the clip is an instanced clip.
Status Codes:

bool MFnClip::isPose ( MStatus ReturnStatus = NULL  ) 

Return true or false as to whether the clip node represents a pose.

Parameters:
[out] ReturnStatus return status
Returns:
True or false as to whether the clip is a pose.
Status Codes:

MObject MFnClip::sourceClip ( MStatus ReturnStatus = NULL  ) 

Return the source clip associated with the MFnClip's clip

Parameters:
[out] ReturnStatus return status
Returns:
MObject containing the associated source clip.
Status Codes:
  • MS::kSuccess operation successful
  • MS::kObjectDoesNotExist this clip does not have an associated source clip
  • MS::kFailure this function set does not have a valid clip object

double MFnClip::getPreCycle ( MStatus ReturnStatus = NULL  ) 

Return the value of this clip's pre cycle attribute

Parameters:
[out] ReturnStatus return status
Returns:
The value of this clip's pre cycle attribute.
Status Codes:

double MFnClip::getPostCycle ( MStatus ReturnStatus = NULL  ) 

Return the value of this clip's post cycle attribute

Parameters:
[out] ReturnStatus return status
Returns:
The value of this clip's post cycle attribute.
Status Codes:

double MFnClip::getCycle ( MStatus ReturnStatus = NULL  ) 

This method is obsolete.

Deprecated:
Use the method MFnClip::getPostCycle instead.
Parameters:
[out] ReturnStatus return status
Returns:
The value of this clip's cycle attribute.
Status Codes:

double MFnClip::getWeight ( MStatus ReturnStatus = NULL  ) 

Return the value of this clip's weight attribute

Parameters:
[out] ReturnStatus return status
Returns:
The value of this clip's weight attribute.
Status Codes:

double MFnClip::getScale ( MStatus ReturnStatus = NULL  ) 

Return the value of this clip's scale attribute

Parameters:
[out] ReturnStatus return status
Returns:
The value of this clip's scale attribute.
Status Codes:

bool MFnClip::getAbsolute ( MStatus ReturnStatus = NULL  ) 

This method is obsolete.

Deprecated:
Use the method MFnClip::getAbsoluteChannelSettings instead.
Parameters:
[out] ReturnStatus return status
Returns:
The value of this clip's offset attribute.
Status Codes:

bool MFnClip::getEnabled ( MStatus ReturnStatus = NULL  ) 

Return the value of this clip's enable attribute

Parameters:
[out] ReturnStatus return status
Returns:
The value of this clip's enable attribute.
Status Codes:

MTime MFnClip::getStartFrame ( MStatus ReturnStatus = NULL  ) 

Return the value of this clip's start frame

Parameters:
[out] ReturnStatus return status
Returns:
The value of this clip's start frame.
Status Codes:

MTime MFnClip::getSourceStart ( MStatus ReturnStatus = NULL  ) 

Return the value of the start frame of this clip's source clip. The sourceStart and sourceDuration define the region of the animCurve that is treated as the clip.

Parameters:
[out] ReturnStatus return status
Returns:
The value of this clip's source start frame.
Status Codes:
  • MS::kSuccess operation successful
  • MS::kFailure this function set does not have a valid clip object
  • MS::kObjectDoesNotExist this clip does not have an associated source clip

MTime MFnClip::getSourceDuration ( MStatus ReturnStatus = NULL  ) 

Return the value of the start frame of this clip's source duration. The sourceStart and sourceDuration define the region of the animCurve that is treated as the clip.

Parameters:
[out] ReturnStatus return status
Returns:
The value of this clip's source duration.
Status Codes:
  • MS::kSuccess operation successful
  • MS::kFailure this function set does not have a valid clip object
  • MS::kObjectDoesNotExist this clip does not have an associated source clip

MStatus MFnClip::getMemberAnimCurves ( MObjectArray curves,
MPlugArray associatedAttrs 
)

Return two arrays: the first contains the animCurves associated with this clip. The second contains the character member that is driven by this animCurve.

Parameters:
[out] curves array to store the result curves
[out] associatedAttrs array to store the character members
Returns:
Return status
Status Codes:
  • MS::kSuccess operation successful
  • MS::kFailure this function set does not have a valid clip object
  • MS::kObjectDoesNotExist this clip does not have an associated source clip

MStatus MFnClip::getAbsoluteChannelSettings ( MIntArray absoluteChannels  ) 

Return an array indicating which channels of the clip are absolute and which are relative. The length of the array is equal to the members in the character. A value of one in the array indicates absolute and a value of 0 indicates relative.

Parameters:
[out] absoluteChannels array to store the result
Returns:
Return status
Status Codes:

int MFnClip::getTrack ( MStatus ReturnStatus = NULL  ) 

Return the track number for the clip. Track indices are one-based. If a track index of zero is returned, it indicates that a track has not yet been assigned to the clip.

Parameters:
[out] ReturnStatus return status
Returns:
The index of this clip's track
Status Codes:
  • MS::kSuccess operation successful
  • MS::kFailure this clip is a source clip and does not have a track
  • MS::kObjectDoesNotExist this function set does not have a valid clip object

MStatus MFnClip::setPoseClip ( bool  state,
MDGModifier mod = NULL 
)

Specify whether or not this clip node should be tagged as a pose rather than a clip. By default, clip nodes are not poses.

Parameters:
[in] state true, to tag the clip as a pose
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:

MStatus MFnClip::setPreCycle ( double  cycle,
MDGModifier mod = NULL 
)

Specify the pre cycle value for the clip.

Parameters:
[in] cycle cycle value
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:

MStatus MFnClip::setPostCycle ( double  cycle,
MDGModifier mod = NULL 
)

Specify the post cycle value for the clip.

Parameters:
[in] cycle cycle value
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:

MStatus MFnClip::setCycle ( double  cycle,
MDGModifier mod = NULL 
)

This method is obsolete.

Deprecated:
Use the method MFnClip::setPostCycle instead.
Parameters:
[in] cycle cycle value
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:

MStatus MFnClip::setWeight ( double  wt,
MDGModifier mod = NULL 
)

Specify a weight value for the clip.

Parameters:
[in] wt weight value
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:

MStatus MFnClip::setScale ( double  scale,
MDGModifier mod = NULL 
)

Specify a scale value for the clip.

Parameters:
[in] scale scale value
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:

MStatus MFnClip::setAbsolute ( bool  abs,
MDGModifier mod = NULL 
)

This method is obsolete.

Deprecated:
Use the method MFnClip::setAbsoluteChannelSettings instead.
Parameters:
[in] abs true if absolute, false if relative
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:

MStatus MFnClip::setEnabled ( bool  val,
MDGModifier mod = NULL 
)

Specify whether or not the clip is enabled. Note: should not be called for source clips since the enabled attribute is ignored on source clips.

Parameters:
[in] val enable value
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:

MStatus MFnClip::setStartFrame ( const MTime start,
MDGModifier mod = NULL 
)

Specify the start frame for the instanced clip. Note: should not be called for source clips since the start frame attribute is ignored on source clips.

Parameters:
[in] start start frame value
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:

MStatus MFnClip::setSourceData ( const MTime start,
const MTime duration,
MDGModifier mod = NULL 
)

Specify the start frame and duration for the source clip associated with this clip.

Parameters:
[in] start source start frame value
[in] duration source duration value
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:
  • MS::kSuccess operation successful
  • MS::kFailure this function set does not have a valid clip object
  • MS::kObjectDoesNotExist this clip does not have an associated source clip

MStatus MFnClip::setTrack ( int  trackIndex,
MDGModifier mod = NULL 
)

Specify the one-based track number for the clip.

Parameters:
[in] trackIndex the track number for the clip
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status
Status Codes:
  • MS::kSuccess operation successful
  • MS::kFailure this function set does not have a valid clip object
  • MS::kObjectDoesNotExist clip track value cannot be set

MStatus MFnClip::setAbsoluteChannelSettings ( const MIntArray absoluteChannels,
MDGModifier mod = NULL 
)

Set which channels of the clip are absolute and which are relative. The length of the specified array should be equal to the number of members in the character. A value of one in the array indicates absolute and a value of 0 indicates relative.

Parameters:
[in] absoluteChannels array containing the absolute channels to be set
[in] mod modifier to use when calling this method from commands that support undo
Returns:
Return status
Status Codes:
  • MS::kSuccess operation successful
  • MS::kObjectDoesNotExist this function set does not have a valid clip object


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