This is simple Python Tag example that daisy chains children’s specific parameter and then you can control sequentially linked parameters. In this example there is a couple Sweep Objects and their ‘End Growth’ parameter is linked to the Master Slider.
Master Slider
If you have for example 20 children and want that 6 first are 100%, you should use following formula in theMaster Slider’s input field:
(100 / [childrencount]) * [nth child]
So in this case we would input: (100 / 20) * 6. It is recommended that linked parameter uses float values. If parameter uses different value than percentage, change “maxValue” variable accordingly.
import c4d
from c4d import utils as u
def main():
slider = op[c4d.ID_USERDATA,1] # User Data: 'Slider'
obj = op.GetObject() # Get object
children = obj.GetChildren() # Get children list
count = len(children) # Count of children
maxValue = 1 # Parameter's maximum value (In this example it's 100%)
step = (1 / float(count)) # Step size
for i, child in enumerate(children): # Iterate through children
if i == 0: # If first item
r = u.RangeMap(slider, 0, step, 0, maxValue, True) # Map range
else: # If anything else but first item
r = u.RangeMap(slider, step*i, step*(i+1), 0, maxValue, True) # Map range
child[c4d.SWEEPOBJECT_GROWTH] = r # Manipulate child's parameter
Originally I builded this setup for “Connect Spheres” Python Generator. It uses same algorithm in “Sequence” mode.
master_slider_python_tag.c4d
Master Slider 2
Thanks to @cristobalvila for requesting a delay function, I made Master Slider 2. There is options to offset slaves with ‘delay’ slider and remap output values with spline data.

import c4d
from c4d import utils as u
def main():
try: # Try to execute following code
slider = op[c4d.ID_USERDATA,1] # User Data: 'Slider'
delay = op[c4d.ID_USERDATA,3] # User Data: 'Delay'
spline = op[c4d.ID_USERDATA,4] # User Fata: 'Spline'
obj = op.GetObject() # Get object
children = obj.GetChildren() # Get children list
count = len(children) # Count of children
maxValue = 400 # Parameter's maximum value (In this example it's 100%)
step = (1 / float(count)) # Step size
for i, child in enumerate(children): # Iterate through children
z = (delay*count) + (slider-delay)
step = u.RangeMap(slider, 0, 1, 0, z, False)
step = step-(delay*i)
r = u.RangeMap(step, 0, 1, 0, maxValue, True, spline)
child[c4d.PRIM_RECTANGLE_WIDTH] = r # Manipulate child's parameter
except: # If comething went wrong
pass # Do nothing
I’ll keep these files separated, since they operate a bit differently.
Updated 30/05/2019
> Added Master Slider 2 setup
master_slider_2_python_tag.c4d