Tag Archives: node

some Nuke Python snippets

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19

Seeing as I’ve found very little reference for the use of python in nuke on the web I thought I’d create this post and add to it with little code snippets.

If anyone has some cool snippets to share please feel free to leave them in a comment below.

*lastupdated: 26 April 2012

delete all nodes that are not selected

s = nuke.selectedNodes()
b = nuke.allNodes()
 
for n in b:
    if n not in s:
        nuke.delete(n)

selects all dependencies (input nodes & their parents) from a selected node

a = nuke.selectedNode()
nodesToSelect = []
 
nodesToSelect.append(a)
def climb(node):
    # print node.name()
    for n in node.dependencies():
        nodesToSelect.append(a)
        climb(n)
 
climb(a)
 
for x in nodesToSelect:
	print x.name()
    # x.setSelected(1)

set all Read nodes to cache locally

for a in nuke.allNodes():
    if a.Class()=='Read':
        a['cached'].setValue(1)
        a['cacheLocal'].setValue(0)

print last frame of script

print nuke.root()['last_frame'].value()

create a backdrop based on selected Nodes

margin = 100
xpMax = nuke.selectedNode().xpos()
xpMin = nuke.selectedNode().xpos()
ypMax = nuke.selectedNode().ypos()
ypMin = nuke.selectedNode().ypos()
 
for a in nuke.selectedNodes():
    if a.xpos() > xpMax:
        xpMax = a.xpos()
    if a.xpos() < xpMin:
        xpMin = a.xpos()
    if a.ypos() > ypMax:
        ypMax = a.ypos()
    if a.ypos() < ypMin:
        ypMin = a.ypos()
 
bd = nuke.nodes.BackdropNode(bdwidth=(xpMax-xpMin)+margin, bdheight=(ypMax-ypMin)+margin) 
bd.setXpos(xpMin-margin/2)
bd.setYpos(ypMin-margin/2)

disable “postage stamps” on only “Read” nodes

for a in nuke.allNodes():
   if a.Class()=='Read':
       a['postage_stamp'].setValue(0)

disable “postage stamps” on all nodes

for a in nuke.allNodes():
    try:
        a['postage_stamp'].setValue(0)
    except:
        pass

“unhide” all nodes’ inputs – useful when receiving a sneaky comp/lighting script

for a in nuke.allNodes():
    try:
        a['hide_input'].setValue(0)
    except:
        pass

change the “first” frame of all selected nodes that are “Read” nodes:
(example changes the first frame to 1018)

for a in nuke.selectedNodes():
    if a.Class() == 'Read':
        a['first'].setValue(1018)

print a selected nodes’ methods

import struct
node = nuke.selectedNode()
for a in node['lookup'].animations():
    print dir(a)

print inputs (dependencies) of a selected node:

for a in nuke.selectedNode().dependencies():
    print a.name()

print outputs (dependents) of a selected node:

for a in nuke.selectedNode().dependent():
    print a.name()

find all the TimeOffset nodes in a Group called “Group2″, and change the value of each offset based on it’s position in the array of found time offsets

tos = []
for a in nuke.toNode('Group2').nodes():
	if a.Class()=='TimeOffset':
		tos.append(a)
for b in tos:
	b['time_offset'].setValue(tos.index(b))

set the ‘bbox’ for any selected Merge, Keymix & Copy nodes to “B”

for a in nuke.selectedNodes():
	classTypes = ['Merge' , 'Keymix', 'Copy', ]
	for n in classTypes:
		if n in a.Class():
			for p in a['bbox'].values():
				if 'B' in p:
					a['bbox'].setValue(a['bbox'].values().index(p))

remove all animation from a selected nodes

for a in nuke.selectedNode().knobs():
	nuke.selectedNode()[a].clearAnimated()

add keyframes – animate a mix

for a in nuke.selectedNodes():
	a['mix'].setAnimated()
	a['mix'].setValueAt(1,nuke.frame())
	a['mix'].setValueAt(0,(nuke.frame() - 1))

half the colour value of all the Constant nodes in a script

for a in nuke.allNodes():
	if a.Class() == "Constant":
		a['color'].setValue(a['color'].value()[0] / 2 , 0)
		a['color'].setValue(a['color'].value()[1] / 2 , 1)
		a['color'].setValue(a['color'].value()[2] / 2 , 2)

find all the transform nodes in a script, and if their input is a Crop, set the ‘scale’ value to be twice it’s current value (also checks if the scale is a list/array or a float)

for a in nuke.allNodes():
	if a.Class() == "Transform":
		if a.input(0).Class() == "Crop":
			x = a['scale'].value()
			if type(x).__name__ == 'list':
				a['scale'].setValue(x[0] * 2 , 0)
				a['scale'].setValue(x[1] * 2 , 1)
			if type(x).__name__ == 'float':
				a['scale'].setValue(x*2)

set all the gain values of all ColorCorrect nodes to be twice their current value

for a in nuke.allNodes():
	if a.Class() == "ColorCorrect":
		a['gain'].setValue(a['gain'].value() * 2)

print files with ‘mov’ in filename

for a in nuke.allNodes():
	if 'Read' in a['name'].value():
		if 'mov' in a['file'].value():
			print a['file'].value()

change font size of all “write” nodes in script

for a in nuke.selectedNodes():
	if "Write" in a['name'].value():
		a['note_font_size'].setValue(60)

create 20 constants with incrementing colour values

def makeConstants(amount):
	for i in range(amount):
		a= nuke.nodes.Constant()
		color= float( float(i) / float(amount) )
		a['color'].setValue(color)
makeConstants(20)

change the name of all Text nodes to contents the text “message”

for a in nuke.allNodes():
    if a.Class()=='Text':
        a.setName(a['message'].value())

##Expressions
(in an expression node) – alpha channel – if the y value of the pixel is even, make it 0, else make it 1 (for viewing fields?)
y%2==1?0:1