nuke.AnimationKey

class nuke.AnimationKey

Bases: object

A control point for an animation curve. @var x The horizontal position of the point @var y The vertical position of the point @var lslope The derivative to the left of the point. If interpolation does not have USER_SET_SLOPE then this may not be correct until after evaluate() has been called. @var rslope The derivative to the right of the point. If interpolation does not have USER_SET_SLOPE then this may not be correct until after evaluate() has been called. @var la The left ‘bicubic’ value. This represents the horizontal position of the left bezier handle end, where 1.0 means 1/3 of the distance to the previous point. If both handles for a span are 1.0 then the horizontal interpolation is linear and thus the vertical interpolation a cubic function. The legal values are 0 to 3. Setting outside of this range will produce undefined results. @var ra The right ‘bicubic’ value, again the legal range is 0 to 3. @var interpolation Used to calculate all the slopes except for the left slope of the first key and the right slope of the last key. Legal values are: - USER_SET_SLOPE: If this bit is on, the slopes are fixed by

the user and interpolation and extrapolation are ignored.

• CONSTANT: The value of the curve is equal to the y of the

  point to the left.

• LINEAR: slopes point directly at the next key.

• SMOOTH: same as CATMULL_ROM but the slopes are clamped so that the

  convex-hull property is preserved (meaning no part of the curve extends vertically outside the range of the keys on each side of it). This is the default.

• CATMULL_ROM: the slope at key n is set to the slope between the control

  points n-1 and n+1. This is used by lots of software.

• cubic: the slope is calculated to the only cubic interpolation which makes

  the first and second derivatives continuous. This type of interpolation was very popular in older animation software. A different cubic interpolation is figured out for each set of adjacent points with the CUBIC type.

• for the smooth, CATMULL_ROM, and CUBIC interpolations, the first and last key have slopes calculated so that the second derivative is zero at them.

@var extrapolation controls how to set the left slope of the first point and the right slope of the last point. Notice that this can be set differently on the first and last points, and is also remembered on all internal points so if end points are deleted old behavior is restored). - constant: the left slope of the first point, and the right slope of the last

point, are set to zero.

• linear: (and all other values): The left slope of the first point is set

  equal to it’s right slope (calculated by the interpolation).

the right slope of the last point is set equal to it’s left slope. if there is only one point both slopes are set to zero. @var selected True if the point is selected in the curve editor.

Methods

Attributes

extrapolation	Controls how to set the left slope of the first point and the right slope of the last point
interpolation	Used to calculate all the slopes except for the left slope of the first key and the right slope of the last key
la	The left ‘bicubic’ value
lslope	The derivative to the left of the point
ra	The right ‘bicubic’ value
rslope	The derivative to the right of the point
selected	True if the point is selected in the curve editor
x	The horizontal position of the point
y	The vertical position of the point

extrapolation

Controls how to set the left slope of the first point and the right slope of the last point

interpolation

Used to calculate all the slopes except for the left slope of the first key and the right slope of the last key

la

The left ‘bicubic’ value

lslope

The derivative to the left of the point

ra

The right ‘bicubic’ value

rslope

The derivative to the right of the point

selected

True if the point is selected in the curve editor

x

The horizontal position of the point

y

The vertical position of the point