PYTHON FOR NUKE (in a nutshell 🌰) - WIP

Useful things in Nuke Python Module (I am gonna assume you know the general logic of coding).

Only includes the things that are often used, you can go HERE to read the Nuke Bible, aka Nuke Python API.

# Create Nodes
nuke.createNode('<node class>', inpanel=False)
nuke.createNode("<node class>", "<knob name> <knob value> <knob name> <knob value>")
nuke.nodes.Grade(knob=knobvalue, inputs=[node])

# Accessing Nodes
nuke.selectedNode() # One selected node
nuke.selectedNodes() # Multiple selected nodes
nuke.toNode('<nodeName>') # one node by its name

# Set Inputs
node.setInput(0, node)

# Referencing Nodes
node.dependencies(nuke.INPUTS | nuke.EXPRESSIONS | nuke.HIDDEN_INPUTS) # Reference Nodes from inputs
node.dependent() # Reference Nodes from outputs

# Layers/Channels
nuke.Layer('layerName', ['layerName.red', 'layerName.green', 'layerName.blue']) # Create Layer
nuke.layers(node) # Return list of layer names

# DAG Position/Size
node.xpos() # left: -, right: +
node.ypos() # up: -, down: +
node.screenWidth() # Avg Node Width: 80
node.screenHeight() # Avf Node Height: 74
BackdropNode.knob('bdwidth') # for BackdropNode specifically
BackdropNode.knob('bdheight') # for BackdropNode specifically

node.setXpos() # integer
node.setYpos() # integer

nuke.zoom(2, [x,y]) # Focus DAG to [x,y]

Group Nodes

# Accessing nodes within a group
# Method 1
with groupNode:
	# functions

# Method 2
group_node.begin()
# functions
group_node.end()

# Method 3
nuke.toNode('groupNode.insideNode')

☰

Knobs

# Adding Knobs
knob = nuke.PyScript_Knob('name','label','value')
knob.clearFlag(nuke.STARTLINE)
knob.setFlag(nuke.STARTLINE)
node.addKnob(knob)
knob.setFlag(0x00008000) # Another way of setting flags, expecting integer list from Nukepidia

# Expression/Animation
knob.clearAnimated()
knob.isAnimated() # Boolean
knob.setExpression('$gui')
knob.hasExpression() # Boolean

# Autolabel - this replace the built-in autolabel for the notes and can not parse tcl expressions
customLabel = "nuke.thisNode().name()+'\\n'+nuke.thisNode()['knobname'].value()" #'\\n' for new line
customLabel_ifs = "nuke.thisNode().name() + (' big!' if nuke.thisNode()['size'].value()>100 else ' small')" # With a if statement
# (<True Action> if <True Condition> else <Else Action>)

nuke.selectedNode()['autolabel'].setValue(customLabel)

☰

List of Knob Types with Python API

Knob Type (Class Object)	Arguments	Human readable / Annotations
AColor_Knob	'name', 'label'	RGB+Alpha
Array_Knob	'name', 'label', int	Matrix like length defined by int
Axis_Knob	'name', 'label'
BBox_Knob	'name', 'label'	x,y,r/w,t/h
Bitmask_Knob	'name', 'label'	will crash your nuke
Boolean_Knob	'name', 'label'	checkbox
Box3_Knob	'name', 'label'	x,y,n,r,t,f (n: near, f: far)
Channel_Knob	'name', 'label'
CascadingEnumeration_Knob	'name', 'label', [list, list/sublist]	dropdown menu
ChannelMask_Knob	'name', 'label'
ColorChip_Knob	'name', 'label'	Floating color wheel
Color_Knob	'name', 'label'	RGB
Double_Knob	'name', 'label'	floating slider
Enumeration_Knob	'name', 'label', [list]	dropdown menu
EvalString_Knob	'name', 'label', 'string'	not sure the use of it
Eyedropper_Knob	'name', 'label'
File_Knob	'name', 'label' 'url string'
Font_Knob	'name', 'label'
Format_Knob	'name', 'label'
GeoSelect_Knob	'name', 'label'
Histogram_Knob	'name', 'label'
IArray_Knob	'name', 'label', [int,int]	Matrix array, int [row,column]
Int_Knob	'name', 'label'
Keyer_Knob	'name', 'label'
Obsolete_Knob	'name', 'label'	don't know why it's here
Password_Knob	'name', 'label'
Pulldown_Knob	'name', 'label', {'key': 'python value'}	parse string into python command
PyCustom_Knob	'name', 'label', cmd	for pyqt application inside a knob UI
PyScript_Knob	'name', 'label', cmd	Python button
Range_Knob	'name', 'label', [float,float,float,...]	Similar to that of Histogram slider
String_Knob	'name', 'label'	Text input
Scale_Knob	'name', 'label'
SceneView_Knob	'name', 'label'
Tab_Knob	'name', 'label'
Text_Knob	'name', 'label'	Title text with CSS
Transform2d_Knob	'name', 'label'
Link_Knob	'name', 'label'	use `makeLink(nodename, 'knob')` to link between knobs
LookupCurves_Knob	'name', 'label'	use addCurve('curveName') to add a new curve
MultiView_Knob	'name', 'label'
ViewView_Knob	'name', 'label'
UV_Knob	'name', 'label'
WH_Knob	'name', 'label'	simlier to Transfrom's scale knob
XYZ_Knob	'name', 'label'
XY_Knob	'name', 'label'

PyCustom Knob

pyside widgets inside a nuke gizmo

define widget as a Class, inheret from nukescripts.PythonPanel or QWidget and Define makeUI(self) inside the Class Wraper

Example:

from PySide import QtGui, QtCore
import nuke

class MyWidget(QtGui.QWidget):

    def __init__(self, node):
        super(self.__class__, self).__init__()

        self.node = node

        layout = QtGui.QHBoxLayout()
        layout.setAlignment(QtCore.Qt.AlignTop)
        self.setLayout(layout)

        btn1 = QtGui.QPushButton('Node Name')
        btn1.clicked.connect(self.btn1Clicked)

        btn2 = QtGui.QPushButton('Print Stuff')
        btn2.clicked.connect(self.btn2Clicked)

        dial = QtGui.QDial()
        dial.valueChanged.connect(self.dialValueChanged)

        layout.addWidget(btn1)
        layout.addWidget(btn2)
        layout.addWidget(dial)


    def btn1Clicked(self):
        print self.node.name()

    def btn2Clicked(self):
        print 'Hi, I\'m a button.'

    def dialValueChanged(self):
        print 'Value was just changed!'

    def makeUI(self):
        return self

    def updateValue(self):
        pass


if __name__ == '__main__':
    node = nuke.selectedNode()
    knob = nuke.PyCustom_Knob( "MyWidget", "", "MyWidget(nuke.thisNode())" )
    node.addKnob(knob)

☰

Tabs

☰

Menu Items

kuMu = nuke.menu('Nuke').addMenu('KU')
kuMu.addCommand('menuLocation', 'functionName', 'alt+c', icon='/img.png', shortcutContext=2)
# shortcutContext: 0=window, 1=Application, 2=DAG

Other Manus

nuke.menu('Animation'): right click menu for Animation icon
nuke.menu('Properties'): right-click menu for the Property panel

☰

Panels

p = nuke.Panel('Simple Panel')

p.addClipnameSearch('clip path', '/tmp')
p.addFilenameSearch('file path', '/tmp')
p.addTextFontPulldown('font browser', '/myFonts/')
p.addRGBColorChip('some pretty color', '')
p.addExpressionInput('enter an expression', '4*25')
p.addBooleanCheckBox('yes or no?', True)
p.addEnumerationPulldown('my choices', 'A B C')
p.addScriptCommand('tcl or python code', '')
p.addSingleLineInput('just one line', 'not much space')
p.addMultilineTextInput('multiple lines of user input text', 'lineA\nlineB')
p.addNotepad('write something', 'some very long text could go in here. For now this is just some random default value')
p.addPasswordInput('password', 'donttellanyone')
p.addButton('push here') # return: 0
p.addButton('or here') # return: 1
p.addButton('or even here') # return: 2
p.show()


pp = nukescripts.PythonPanel('Python Panel')

knob = nuke.Double_Knob('knobtype','knoblabel')
pp.addKnob(knob)
pp.show() # Floating and dockable
pp.addToPane() # Docked on create

☰

Callbacks

# KnobChanged
nuke.addKnobChanged(functionName, nodeClass='PostageStamp') # functionName use without quotes

☰

Rotoshapes

Everything rotoshapes, very different, very annoying

nuke Roto Rotopaint NDK reference

There are 3 types of elements in Rotoshape/Roto node:

Layer: Groups/Layers, exclude Root (that returns a NoneType, use rootLayer)
Stroke: Paint strokes, Dodges
Shape: Anything Spline - Bezier, BSpline, Ecllips, Recotangle...

rootLayer: Contains all above elements in the node, iterable; when shape inside a layer, returns the layer object

n = nuke.toNode('Roto')
k = n['curves'] # Roto node rotoshape curve object

k.getSelected() # return: Iterable, Selected Rotoshapes as list
k.toElement('Rotoshape') # return: object, object refered by its name
k.toElement('Layer/Rotoshape') # return: object, shape inside a layer
k.getTransform() # return: object, AnimCTransform (whatever that is)
elem = [c for c in k.rootLayer] # return: every elements inside the Roto node

Expression link Transform of a Rotoshape curve

sometimes it will be faster just to right-click or control-drag on animation parameter

link_tools.py(sample script) | _curvelib.AnimCTransform methods

Basic Event Sequence:

Define _curvelib.AnimCurve() object (per knob and axis)
Assign a string value to <AnimCurve Object>.expressionString = 'Expression'
Set <AnimCurve Object>.useExpression = True
Find Transform Attribute object for selected Rotoshape curve <Curve object>.getTransform()
Set Expressions (Translation, Rotation, Scale, PivotPoint)
- <Attribute object>.setTranslationAnimCurve(index, <AnimCurve object>) - 0: x, 1: y
- <Attribute object>.setRotationAnimCurve(2, <AnimCurve object>) - why index is 2
- <Attribute object>.setScaleAnimCurve(index, <AnimCurve object>) - 0: x, 1: y
- <Attribute object>.setPivotPointAnimCurve(index, <AnimCurve object>) - 0: x, 1: y

☰

Pipeline Integration

Startup

script to execute on startup nuke.addOnCreate(function, nodeClass='Root')

Other

# Color Value Convert
int('%02x%02x%02x%02x' % (r,g,b,a), 16) # RGB -> Nuke; r,g,b,a: 0~255
int('%sFF' % ('2D2D2D'),16) # HEX -> Nuke

# Default custom knob default value
nuke.selectedNode()['knob'].setDefaultValue([1.0]) # Value must be a sequence/arry

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

NukeModule.md

NukeModule.md

PYTHON FOR NUKE (in a nutshell 🌰) - WIP

Table of Contents

Directories for python scripts

Structure

Nodes Tabs Knobs

Nodes

Group Nodes

Knobs

List of Knob Types with Python API

PyCustom Knob

Tabs

Menu Items

Panels

Callbacks

Rotoshapes

Expression link Transform of a Rotoshape curve

Pipeline Integration

Startup

Other

Files

NukeModule.md

Latest commit

History

NukeModule.md

File metadata and controls

PYTHON FOR NUKE (in a nutshell 🌰) - WIP

Table of Contents

Directories for python scripts

Structure

Nodes Tabs Knobs

Nodes

Group Nodes

Knobs

List of Knob Types with Python API

PyCustom Knob

Tabs

Menu Items

Panels

Callbacks

Rotoshapes

Expression link Transform of a Rotoshape curve

Pipeline Integration

Startup

Other