setRotoLifeTime()

I recently came across this script, https://www.nukepedia.com/python/nodegraph/lifetimeroto . I really liked the idea but found it were multiple shape objects in the curve knob. I also wanted to add some functionality to be able to additional layers nested inside the root. This is the full code. use it as you see fit!

#::::::::::::::::::::::::::::    
#:::: SET ROTO LIFETIME ::::
#::::::::::::::::::::::::::::    
# Robert Matier 
# Version: 1.0.0
# Last Updated: 2025/02/03

# Looks at all selected nodes if nodes Class is 'Roto' or 'RotoPaint'
# Recursively look through all the objects in the nodes curve knob
# if they are Shape we check if there is animation on that node
# if there is animation we set the lifetime attribute to match the animation

import nuke.rotopaint as rp


#----parseLayer----

# pass in a starting curve knob  object (root), a list of names (noe at start), and a string tp track the parents (none at start)  
# recursively gather all shapes and returns a list with all their names
def parseLayer(rootLayer, listNames, parents):

    for rotoObject in rootLayer:
        #if we are looking at a layer we need to modify the parent name and go a level deeper to see if there are shapes 
        if isinstance(rotoObject, rp.Layer):
            curName = rotoObject.name         
            parentNames = parents + curName + '/'             
            listNames = parseLayer(rotoObject, listNames, parentNames)
        #we are ignoring strokes      
        elif isinstance(rotoObject, rp.Stroke):
            continue
        else:
            # if the shape has parrents we need to add them to the name 
            if parents:
                newObject = parents + rotoObject.name
                listNames.append(newObject)
            # we are at the root layer and there are no parent layers     
            else:
                listNames.append(rotoObject.name)
    
    return listNames


#----setRotoLife----

# Takes a user selection of nodes and actions on  nodes with Class 'Roto' or 'RotoPaint'
# Looks at the nodes curve knob and using the parseLayer() iterates through a list of all the available shape objects
# At each shape object gets all the keyframes storing the lowest and highest values
# sets the objects lifetime attributes based on these values. 

def setRotoLifeTime():
    selNodes = nuke.selectedNodes()
    if len(selNodes) == 0:
        nuke.message('No nodes selected, please select Roto or RotoPaint nodes.')
        return
    
    ### find selected roto shapes keyframes
    for node in selNodes:
        if node.Class() not in ('Roto','RotoPaint'):
            continue
        elementNames = []
        parentNames = ''
        cKnob = node['curves']
        root = cKnob.rootLayer
        listNames = parseLayer(root, elementNames, parentNames)

        for name in listNames:
            currentObject = cKnob.toElement(name)          
            keyFrame = currentObject[0].center.getControlPointKeyTimes()
            keyFrames = [int(i) for i in keyFrame]
            low = (min(keyFrames))
            high = (max(keyFrames))
            attrs = currentObject.getAttributes() 
            if low != high:
                attrs.set('ltn', low) #lifetime_start
                attrs.set('ltm', high)#lifetime_end
                attrs.set('ltt', 4) #lifetime_type

        
setRotoLifeTime()