Cinema 4D Hierarchy Iterator helper for iterating over all object

HierarchyIterator.py

def GetNextObject(op, op_stop=None):
    """
    Hierarchy iteration helper from https://developers.maxon.net/?p=596
    :param op_stop: The object to stop at. Returns None when this object is found.
    :type op_stop: c4d.BaseObject
    :param op: the object to get the next node from
    :return: The next object
    """
    if op is None:
        return None

    if op.GetDown():
        return op.GetDown()

    while not op.GetNext() and op.GetUp():
        op = op.GetUp()

        if op == op_stop:
            return None

    if op == op_stop:
        return None

    return op.GetNext()