keyTangent

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Synopsis

keyTangent [-absolute] [-animation string] [-attribute string] [-controlPoints boolean] [-float floatrange] [-global] [-hierarchy string] [-inAngle angle] [-inTangentType string] [-inWeight float] [-includeUpperBound boolean] [-index uint] [-ix float] [-iy float] [-lock boolean] [-outAngle angle] [-outTangentType string] [-outWeight float] [-ox float] [-oy float] [-relative] [-shape boolean] [-stepAttributes boolean] [-time timerange] [-weightLock boolean] [-weightedTangents boolean] [objects]

keyTangent is undoable, queryable, and editable.

The animation curves comprising a keyset depend on the value of the "-animation" flag:

• keysOrObjects:
  1. Any active keys, when no target objects or -attribute flags appear on the command line, or
  2. All animation curves connected to all keyframable attributes of objects specified as the command line's targetList, when there are no active keys.
• keys: Only act on active keys or tangents. If there are no active keys or tangents, don't do anything.
• objects: Only act on specified objects. If there are no objects specified, don't do anything.

Note that the "-animation" flag can be used to override the curves uniquely identified by the multi-use "-attribute" flag, which takes an argument of the form attributeName, such as "translateX".

Keys on animation curves are identified by either their time values or their indices. Times and indices can be given individually or as part of a list or range.

• -time 10pal means the key at frame 10 (PAL format).
• -time 1.0sec -time 15ntsc -time 20 means the keys at time 1.0 second, frame 15 (in NTSC format), and time 20 (in the currently defined global time unit).
• -time "10:20" means all keys in the range from 10 to 20, inclusive, in the current time unit.

• -time "10:" means all keys from time 10 (in the current time unit) onwards.
• -time ":10" means all keys up to (and including) time 10 (in the current time unit).
• -time ":" is a short form to specify all keys.

• -index 0 means the first key of each animation curve. (Indices are 0-based.)
• -index 2 -index 5 -index 7 means the 3rd, 6th, and 8th keys.
• -index "1:5" means the 2nd, 3rd, 4th, 5th, and 6th keys of each animation curve.

This command edits or queries tangent properties of keyframes in a keyset. It is also used to edit or query the default tangent type of newly created keyframes (see the setKeyframe command for more information on how to override this default).

Tangents help manage the shape of the animation curve and affect the interpolation between keys. The tangent angle specifies the direction the curve will take as it leaves (or enters) a key. The tangent weight specifies how much influence the tangent angle has on the curve before the curve starts towards the next key.

Maya internally represents tangents as x and y values. Refer to the API documentation for MFnAnimCurve for a description of the relationship between tangent angle and weight and the internal x and y values.

Return value

In query mode, return type is based on queried flag.

Related

Flags

Long name (short name)	Argument types	Properties
-attribute(-at)	string
List of attributes to select In query mode, this flag needs a value.
-hierarchy(-hi)	string
Hierarchy expansion options. Valid values are "above," "below," "both," and "none." (Not valid for "pasteKey" cmd.) In query mode, this flag needs a value.
-shape(-s)	boolean
Consider attributes of shapes below transforms as well, except "controlPoints". Default: true. (Not valid for "pasteKey" cmd.) In query mode, this flag needs a value.
-controlPoints(-cp)	boolean
This flag explicitly specifies whether or not to include the control points of a shape (see "-s" flag) in the list of attributes. Default: false. (Not valid for "pasteKey" cmd.) In query mode, this flag needs a value.
-index(-in)	uint
index of a key on an animCurve In query mode, this flag needs a value.
-time(-t)	timerange
time uniquely representing a key (or key range) on a time-based animCurve. Valid timeRanges include single values (-t 10) or a string with a lower and upper bound, separated by a colon (-t "10:20") In query mode, this flag needs a value.
-float(-f)	floatrange
value uniquely representing a non-time-based key (or key range) on a time-based animCurve. Valid floatRange include single values (-f 10) or a string with a lower and upper bound, separated by a colon (-f "10:20") In query mode, this flag needs a value.
-includeUpperBound(-iub)	boolean
When the -t/time or -f/float flags represent a range of keys, this flag determines whether the keys at the upper bound of the range are included in the keyset. Default value: true. This flag is only valid when the argument to the -t/time flag is a time range with a lower and upper bound. (When used with the "pasteKey" command, this flag refers only to the time range of the target curve that is replaced, when using options such as "replace," "fitReplace," or "scaleReplace." This flag has no effect on the curve pasted from the clipboard.)
-animation(-an)	string
Where this command should get the animation to act on. Valid values are "objects," "keys," and "keysOrObjects" Default: "keysOrObjects." (See Description for details.)
-global(-g)
Required for all operations on the global tangent type. The global tangent type is used by the setKeyframe command when tangent types have not been specifically applied, except in combination with flags such as 'i/insert' which preserve the shape of the curve. It is also used when keys are set from the menu. The only flags that can appear on a keyTangent command with the 'g/global' flag are 'itt/inTangentType', 'ott/outTangentType' and 'wt/weightedTangents'.
-inTangentType(-itt)	string
Specify the in-tangent type. Valid values are "spline," "linear," "fast," "slow," "flat," "step," "stepnext," "fixed," "clamped," and "plateau." Returns a string[] when queried.
-outTangentType(-ott)	string
Specify the out-tangent type. Valid values are "spline," "linear," "fast," "slow," "flat," "step," "stepnext," "fixed," "clamped," and "plateau." Returns a string[] when queried.
-absolute(-a)
Changes to tangent positions are NOT relative to the current position.
-relative(-r)
Changes to tangent positions are relative to the current position.
-inAngle(-ia)	angle
New value for the angle of the in-tangent. Returns a float[] when queried.
-outAngle(-oa)	angle
New value for the angle of the out-tangent. Returns a float[] when queried.
-inWeight(-iw)	float
New value for the weight of the in-tangent. Returns a float[] when queried.
-ix(-ix)	float
New value for the x-component of the in-tangent. This is a unit independent representation of the tangent component. Returns a float[] when queried.
-iy(-iy)	float
New value for the y-component of the in-tangent. This is a unit independent representation of the tangent component. Returns a float[] when queried.
-outWeight(-ow)	float
New value for the weight of the out-tangent. Returns a float[] when queried.
-ox(-ox)	float
New value for the x-component of the out-tangent. This is a unit independent representation of the tangent component. Returns a float[] when queried.
-oy(-oy)	float
New value for the y-component of the out-tangent. This is a unit independent representation of the tangent component. Returns a float[] when queried.
-lock(-l)	boolean
Lock a tangent so in and out tangents move together. Returns an int[] when queried.
-weightLock(-wl)	boolean
Lock the weight of a tangent so it is fixed. Returns an int[] when queried. Note: weightLock is only obeyed within the graph editor. It is not obeyed when -inWeight/-outWeight are issued from a command.
-weightedTangents(-wt)	boolean
Specify whether or not the tangents on the animCurve are weighted Note: switching a curve from weightedTangents true to false and back to true again will not preserve fixed tangents properly. Use undo instead.
-stepAttributes(-sa)	boolean
The setKeyframe command will automatically set tangents for boolean and enumerated attributes to step. This flag mirrors this behavior for the keyTangent command. When set to false, tangents for these attributes will not be edited. When set to true (the default) tangents for these attributes will be edited.

Flag can appear in Create mode of command	Flag can appear in Edit mode of command
Flag can appear in Query mode of command	Flag can be used more than once in a command.

MEL examples

// Set the in-tangent to spline for all keyframes
// on an object between 1 and 2 seconds.
//
keyTangent -inTangentType spline -time "0sec:2sec" nurbsSphere1;

// Set the angle and value for the out tangent of the
// keyframe at time 5 of nurbsSphere1's translateX.
//
keyTangent  -edit -time 5 -attribute translateX -absolute -outAngle 10 -outWeight 5 nurbsSphere1;