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MFnClip Class Reference

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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.

#include <MFnClip.h>

Inheritance diagram for MFnClip:
Inheritance graph
[legend]

List of all members.

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)
 Creates a source clip node and associates it with this function set.
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)
 Creates an instance of a clip that will be viewable in the Trax editor.
bool isInstancedClip (MStatus *ReturnStatus=NULL)
 Return true or false as to whether the clip node represents the source clip or an instanced clip.
bool isPose (MStatus *ReturnStatus=NULL)
 Return true or false as to whether the clip node represents a pose.
MObject sourceClip (MStatus *ReturnStatus=NULL)
 Return the source clip associated with the MFnClip's clip.
double getPreCycle (MStatus *ReturnStatus=NULL)
 Return the value of this clip's pre cycle attribute.
double getPostCycle (MStatus *ReturnStatus=NULL)
 Return the value of this clip's post cycle attribute.
double getCycle (MStatus *ReturnStatus=NULL)
 This method is obsolete.
double getWeight (MStatus *ReturnStatus=NULL)
 Return the value of this clip's weight attribute.
double getScale (MStatus *ReturnStatus=NULL)
 Return the value of this clip's scale attribute.
bool getAbsolute (MStatus *ReturnStatus=NULL)
 This method is obsolete.
bool getEnabled (MStatus *ReturnStatus=NULL)
 Return the value of this clip's enable attribute.
MTime getStartFrame (MStatus *ReturnStatus=NULL)
 Return the value of this clip's start frame.
MTime getSourceStart (MStatus *ReturnStatus=NULL)
 Return the value of the start frame of this clip's source clip.
MTime getSourceDuration (MStatus *ReturnStatus=NULL)
 Return the value of the start frame of this clip's source duration.
MStatus getMemberAnimCurves (MObjectArray &curves, MPlugArray &associatedAttrs)
 Return two arrays: the first contains the animCurves associated with this clip.
MStatus getAbsoluteChannelSettings (MIntArray &absoluteChannels)
 Return an array indicating which channels of the clip are absolute and which are relative.
int getTrack (MStatus *ReturnStatus=NULL)
 Return the track number for the clip.
MStatus setPoseClip (bool state, MDGModifier *mod=NULL)
 Specify whether or not this clip node should be tagged as a pose rather than a clip.
MStatus setPreCycle (double cycle, MDGModifier *mod=NULL)
 Specify the pre cycle value for the clip.
MStatus setPostCycle (double cycle, MDGModifier *mod=NULL)
 Specify the post cycle value for the clip.
MStatus setCycle (double cycle, MDGModifier *mod=NULL)
 This method is obsolete.
MStatus setWeight (double wt, MDGModifier *mod=NULL)
 Specify a weight value for the clip.
MStatus setScale (double scale, MDGModifier *mod=NULL)
 Specify a scale value for the clip.
MStatus setAbsolute (bool abs, MDGModifier *mod=NULL)
 This method is obsolete.
MStatus setEnabled (bool val, MDGModifier *mod=NULL)
 Specify whether or not the clip is enabled.
MStatus setStartFrame (const MTime &start, MDGModifier *mod=NULL)
 Specify the start frame for the instanced clip.
MStatus setSourceData (const MTime &start, const MTime &duration, MDGModifier *mod=NULL)
 Specify the start frame and duration for the source clip associated with this clip.
MStatus setTrack (int index, MDGModifier *mod=NULL)
 Specify the one-based track number for the clip.
MStatus setAbsoluteChannelSettings (const MIntArray &absoluteChannels, MDGModifier *mod=NULL)
 Set which channels of the clip are absolute and which are relative.
 MFnClip (const MObject &object, MStatus *ReturnStatus=NULL)
 Constructor.

Protected Member Functions

virtual const char * className () const
 Class name.

Constructor & Destructor Documentation

MFnClip ( MObject object,
MStatus ReturnStatus = NULL 
)

Constructor.

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

Parameters:
[in]objectThe MObject to attach the function set to
[out]ReturnStatusthe return status
Status Codes:
MFnClip ( const MObject object,
MStatus ReturnStatus = NULL 
)

Constructor.

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

Parameters:
[in]objectThe MObject to attach the function set to
[out]ReturnStatusthe return status
Status Codes:

Member Function Documentation

MFn::Type type ( ) const [virtual]

Function set type.

Return the class type : MFn::kClip.

Reimplemented from MFnDependencyNode.

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

Class name.

Return the class name : "MFnClip".

Reimplemented from MFnDependencyNode.

MObject 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]sourceStarttime on clip animCurves that represents clip start
[in]sourceDurationtime extent of the clip
[in]dgModcommand modifier used for undo and redo
[out]ReturnStatusreturn status
Returns:
The newly created clip.
Status Codes:
Examples:
createClipCmd.cpp.
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 
)

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

Parameters:
[in]sourceClipthe source clip node
[in]startstart frame where the instance will be scheduled
[in]dgModcommand modifier used for undo and redo
[in]ReturnStatusreturn status
[in]absolutewhether the clip is absolute (1) or relative (0)
[in]preCyclepre cycle for the clip
[in]postCyclepost cycle for the clip
[in]weightweight for the clip
[in]scalescale for the clip
Returns:
The newly created clip.
Status Codes:
Examples:
createClipCmd.cpp.
bool 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]ReturnStatusreturn status
Returns:
True or false as to whether the clip is an instanced clip.
Status Codes:
bool isPose ( MStatus ReturnStatus = NULL)

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

Parameters:
[out]ReturnStatusreturn status
Returns:
True or false as to whether the clip is a pose.
Status Codes:
MObject sourceClip ( MStatus ReturnStatus = NULL)

Return the source clip associated with the MFnClip's clip.

Parameters:
[out]ReturnStatusreturn 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 getPreCycle ( MStatus ReturnStatus = NULL)

Return the value of this clip's pre cycle attribute.

Parameters:
[out]ReturnStatusreturn status
Returns:
The value of this clip's pre cycle attribute.
Status Codes:
double getPostCycle ( MStatus ReturnStatus = NULL)

Return the value of this clip's post cycle attribute.

Parameters:
[out]ReturnStatusreturn status
Returns:
The value of this clip's post cycle attribute.
Status Codes:
double getCycle ( MStatus ReturnStatus = NULL)

This method is obsolete.

Deprecated:
Use the method MFnClip::getPostCycle instead.
Parameters:
[out]ReturnStatusreturn status
Returns:
The value of this clip's cycle attribute.
Status Codes:
double getWeight ( MStatus ReturnStatus = NULL)

Return the value of this clip's weight attribute.

Parameters:
[out]ReturnStatusreturn status
Returns:
The value of this clip's weight attribute.
Status Codes:
double getScale ( MStatus ReturnStatus = NULL)

Return the value of this clip's scale attribute.

Parameters:
[out]ReturnStatusreturn status
Returns:
The value of this clip's scale attribute.
Status Codes:
bool getAbsolute ( MStatus ReturnStatus = NULL)

This method is obsolete.

Deprecated:
Use the method MFnClip::getAbsoluteChannelSettings instead.
Parameters:
[out]ReturnStatusreturn status
Returns:
The value of this clip's offset attribute.
Status Codes:
bool getEnabled ( MStatus ReturnStatus = NULL)

Return the value of this clip's enable attribute.

Parameters:
[out]ReturnStatusreturn status
Returns:
The value of this clip's enable attribute.
Status Codes:
MTime getStartFrame ( MStatus ReturnStatus = NULL)

Return the value of this clip's start frame.

Parameters:
[out]ReturnStatusreturn status
Returns:
The value of this clip's start frame.
Status Codes:
MTime 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]ReturnStatusreturn 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 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]ReturnStatusreturn 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 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]curvesarray to store the result curves
[out]associatedAttrsarray 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 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]absoluteChannelsarray to store the result
Returns:
Return status
Status Codes:
int 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]ReturnStatusreturn 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 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]statetrue, to tag the clip as a pose
[in]modmodifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:
MStatus setPreCycle ( double  cycle,
MDGModifier mod = NULL 
)

Specify the pre cycle value for the clip.

Parameters:
[in]cyclecycle value
[in]modmodifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:
MStatus setPostCycle ( double  cycle,
MDGModifier mod = NULL 
)

Specify the post cycle value for the clip.

Parameters:
[in]cyclecycle value
[in]modmodifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:
MStatus setCycle ( double  cycle,
MDGModifier mod = NULL 
)

This method is obsolete.

Deprecated:
Use the method MFnClip::setPostCycle instead.
Parameters:
[in]cyclecycle value
[in]modmodifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:
MStatus setWeight ( double  wt,
MDGModifier mod = NULL 
)

Specify a weight value for the clip.

Parameters:
[in]wtweight value
[in]modmodifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:
MStatus setScale ( double  scale,
MDGModifier mod = NULL 
)

Specify a scale value for the clip.

Parameters:
[in]scalescale value
[in]modmodifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:
MStatus setAbsolute ( bool  abs,
MDGModifier mod = NULL 
)

This method is obsolete.

Deprecated:
Use the method MFnClip::setAbsoluteChannelSettings instead.
Parameters:
[in]abstrue if absolute, false if relative
[in]modmodifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:
MStatus 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]valenable value
[in]modmodifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:
MStatus 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]startstart frame value
[in]modmodifier to use when calling this method from commands that support undo
Returns:
Return status.
Status Codes:
MStatus 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]startsource start frame value
[in]durationsource duration value
[in]modmodifier 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 setTrack ( int  trackIndex,
MDGModifier mod = NULL 
)

Specify the one-based track number for the clip.

Parameters:
[in]trackIndexthe track number for the clip
[in]modmodifier 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 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]absoluteChannelsarray containing the absolute channels to be set
[in]modmodifier 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

MFnClip MFnClip MFnClip MFnClip MFnClip MFnClip MFnClip MFnClip MFnClip MFnClip
MFnClip MFnClip MFnClip MFnClip MFnClip MFnClip MFnClip MFnClip MFnClip MFnClip