okay the docs you gave were great for insight

working code to change parameter of roughness for x given mat selections

import c4d
import maxon
from maxon import GraphDescription

doc = c4d.documents.GetActiveDocument()

# Get selected materials directly
selected_materials = doc.GetActiveMaterials()

# Modify roughness for each selected material
for material in selected_materials:
    graph = GraphDescription.GetGraph(material, 
                                      nodeSpaceId=maxon.NodeSpaceIdentifiers.RedshiftMaterial)
    
    GraphDescription.ApplyDescription(graph, {
        "$query": {
            "$type": "Standard Material"
        },
        "Reflection/Roughness": 1
    })

c4d.EventAdd()

Hi, I want to change all settings of thickness in Contour node of all toon materials?
Any idea of how to do this?
thanks

import c4d
from c4d import gui

def traverse_nodes(graph, ext_value, int_value):
    """Recursively search nodes in a graph."""
    for node in graph.GetNodes():
        try:
            node_id = node.GetDefinition().GetID()
        except:
            node_id = None

        # Look for the RS Contour node by its ID string
        if node_id == "com.redshift3d.redshift4c4d.nodes.core.contour":
            print(f"✅ Found Contour node in: {node.GetName()}")
            node.SetParameter("com.redshift3d.redshift4c4d.nodes.core.contour.externalthickness", ext_value, c4d.DESCFLAGS_SET_0)
            node.SetParameter("com.redshift3d.redshift4c4d.nodes.core.contour.internalthickness", int_value, c4d.DESCFLAGS_SET_0)

        # Check if the node contains subgraphs
        for port in node.GetInputs() + node.GetOutputs():
            subgraph = port.GetNodeGraph()
            if subgraph:
                traverse_nodes(subgraph, ext_value, int_value)

def main():
    # Get user values
    ext_str = gui.InputDialog("External Thickness", "1.0")
    int_str = gui.InputDialog("Internal Thickness", "1.0")

    try:
        ext_value = float(ext_str)
        int_value = float(int_str)
    except ValueError:
        gui.MessageDialog("Invalid number input.")
        return

    # Loop through all materials
    for mat in doc.GetMaterials():
        if not mat.CheckType(1036224):  # Redshift material
            continue

        node_material = mat.GetNodeMaterialReference()
        if not node_material:
            continue

        # Try all available graphs inside the material
        graphs = node_material.GetGraphs()
        if not graphs:
            continue

        print(f"Scanning material: {mat.GetName()}")

        for graph in graphs:
            traverse_nodes(graph, ext_value, int_value)

    c4d.EventAdd()

if __name__ == "__main__":
    main()

It is not a a support centre issue, it is a dev issue.

The devs changed the algothrims for the tools. The screenshots above clearly show the issues of which the dev team have caused.

Support do not have answers for this, they would just point to documentation.

This is a dev issues, as it is the devs who made the changes.

Please see the screenshots below which show case the issues.
Loop tool and knife tool are useless in R2025, revert back to R23
Why have Maxon changed what used to work.