【NUKE教程】Nuke Python 动画

14 九月, 2016
22
0

nukepythonaim
这部分讲如何搞定动画

设置关键帧

关键帧knob是关键,设置knob来接受动画

node = nuke.createNode(' blur' )
k = node['size']
k.setAnimated()

完成此步骤后就可以用 setValue和setValueAt来设置关键帧了

k.setValue( 5 ) // 在当前帧设置值为5
k.setValueAt( 55, 10)
k.setValueAt( 66, 100 ) 在10,100帧设置值为 55和66
k.setValueAt( 77, 100, 0 )
k.setValueAt( 88, 100, 1 ) 如果knob是数组,那么设置在第100帧设置 第一组为 77, 第二组为88

删除关键帧

查看一个knob是否为动画

node = nuke.createNode( 'Blur')
k = node['size']
k.isAnimated()

如果有动画或者表达式动画就返回true

	
k.hasExpression()

判断是否 有表达式

获取knob的动画曲线

animCurve = k.animation( 0 )
animCurve = k.animation( 1 )

获取一个knob内全部动画曲线

allCurves = k.animations()

打印动画曲线中的所有值

for key in animCurve.keys():
    xValue = key.x
    yValue = key.y
    print 'ket at %s has value %s' % ( xValue, yValue)

清除动画曲线中的所有值

for curve in k.animations():
    curve.clear()

例子

bake动画

这段脚本将所有knob以及附带的表达式bake到关键帧动画里面,首先创建获取帧范围的循环,并在节点间循环

def bakeSelectNodes():
    ret = nuke.getFramesAndViews(' bake curves in selected nodes?', '%s-%s' % (nuke.root().firstFrame(), nuke.root().lastFrame() ) )

这会弹出对话框来,如下:

判断frame是否可用

def bakeSelectedNodes():
    ret = nuke.getFramesAndViews( 'bake curves in selelcted nodes?', '%s-%s' % ( nuke.root().firstFrame(), nuke.root().lastFrame() ))
    if not ret:
        return
    fRange = nuke.FrameRange( ret[0] )
    views = ret[1]

在节点运行bakeExpressionKnobs遍历拷贝

def bakeSelectedNodes():
    ret = nuke.getFramesAndViews('bake curves in selected node', '%s-%s' % ( nuke.root().firstFrame(), nuke.root().lastFrame() ))
    if not ret:
        return
    fRange = nuke.FrameRange( ret[0] )
    views = ret[1]
    for n in nuke.selectedNodes():
        bakeExpressionKnobs(n, fRange.first(), fRange.last(), fRange.increment(), views)

辅助函数
getCurves 返回给定knob的动画曲线

def getCurves( knob, views):
    curves = []
    for v in views:
        curves.extend( knob.animations(v) )
    return curves

bakeCurve 烘焙动画曲线

def bakeCurve( curve, first, last, inc):
    for f in xrange(first, last, inc):
        curve.setKey(f, curve.evaluate(f))
    curve.setExpression( 'curve')

有了上面两个函数就可以写bakeExpressionKnobs了,需要5个参数

def bakeExpression( node, first, last, inc, views):
        expKnobs = [k for k in node.knobs().values() if k.hasExpression() ]

然后就可以运行getCurves了

allCurves = []
for k in expKnobs:
    allCurves += getCurves( k, views )

随后bake数据

for c in allCurves:
    bakeCurve(c, first, last, inc)

完整的bakeExpressionKnobs()

def bakeExpressionKnobs( node, first, last, inc, views ):
    expKnobs = [ k for k in node.knobs().values if k.hasExpression() ]
    allCurves = []
    for k in expKnobs:
        allCurves += getCurves(k, views )
    for c in allCurves:
        bakeCurve( c, first, last, inc)

所有代码:

import nuke
def bakeCurve( curve, first, last, inc ):
    '''bake an expresison curve into a keyframes curve'''
    for f in xrange( first, last, inc ):
        curve.setKey( f, curve.evaluate( f ) )
    curve.setExpression( 'curve' )
####################################################
def getCurves( knob, views ):
    '''return a list of all animation curves found in the given knob'''
    curves = []
    for v in views:
        curves.extend( knob.animations( v ) )
    return curves
####################################################
def bakeExpressionKnobs( node, first, last, inc, views ):
    '''bake all knobs in node that carry expressions'''
    # GET ALL KNOBS WITH EXPRESSIONS IN THEM
    expKnobs = [ k for k in node.knobs().values() if k.hasExpression() ]
    # GET ALL CURVES INSIDE THAT KNOB INCLUDING SPLIT FIELDS AND VIEWS
    allCurves = []
    for k in expKnobs:
        allCurves += getCurves( k, views )
    # BAKE ALL CURVES
    for c in allCurves:
        bakeCurve( c, first, last, inc )
####################################################
def bakeDependentNodes():
    '''Add this to onUserDestroy callback - not yet implemented'''
    parentNode = nuke.thisNode() # THIS IS GIVEN TO US BY THE CALLBACK, i.e. WHEN A NODE IS DELETED - WELL, NOT YET
    depNodes  = parentNode.dependent( nuke.EXPRESSIONS )
    ret = nuke.getFramesAndViews( 'bake curves in dependent nodes?', '%s-%s' % (parentNode.firstFrame(), parentNode.lastFrame()) )
    if not ret:
        return
    fRange = nuke.FrameRange( ret[0] )
    views = ret[1]
    for n in depNodes:
        bakeExpressionKnobs( n, fRange.first(), fRange.last(), fRange.increment(), views )
####################################################
def bakeSelectedNodes():
    '''bake selected nodes' knobs that carry expressions'''
    ret = nuke.getFramesAndViews( 'bake curves in selected nodes?', '%s-%s' % (nuke.root().firstFrame(), nuke.root().lastFrame()) )
    if not ret:
        return
    fRange = nuke.FrameRange( ret[0] )
    views = ret[1]
    for n in nuke.selectedNodes():
        bakeExpressionKnobs( n, fRange.first(), fRange.last(), fRange.increment(), views )

选择节点并执行:

	
bakeSelectedNodes()