Nulls to Spline – Cinema 4D Xpresso&Python Setup

Python

import c4d

def main():
    if not xpresso_null or not tracer:
        return
    global Output1
    # Get all child objects of the input null
    children = xpresso_null.GetChildren()

    # Create an InExcludeData list
    link_list = c4d.InExcludeData()

    # Add each child to the list
    for obj in children:
        if obj:  # safety check
            link_list.InsertObject(obj, 1)  # 1 = include mode

    # Set the Tracer object's Trace Link field
    Output1 = tracer[c4d.MGTRACEROBJECT_OBJECTLIST] = link_list

We needed this Python Xpresso Node to generate In-/Exclusion necessary for Tracer Object List. Make sure to set your tracer and xpresso_null inputs as links. And for the output select In-/Exclusion as its type. You can check the type by right clicking input/output from Port Information dialogue.

You may increase or decrease the null amount under Xpresso null. It will automatically populate Tracer list.

You can animate the spline using Mospline’s Start, End and Offset parameters.