PolySelectionTags_to_Materials.py

'''

Create materials for all Objects Polygon Selection Tags in Cinema 4D using Python API.
Author: Mike Udin
Website: mikeudin.net
Tutorial: https://youtu.be/mJcL6i0SCtY

'''

import c4d
import random

# from pprint import pprint

def get_random_color(pastel_factor = 0.5):
    return [(x+pastel_factor)/(1.0+pastel_factor) for x in [random.uniform(0,1.0) for i in [1,2,3]]]

def color_distance(c1,c2):
    return sum([abs(x[0]-x[1]) for x in zip(c1,c2)])

def generate_new_color(existing_colors,pastel_factor = 0.5):
    max_distance = None
    best_color = None
    for i in range(0,100):
        color = get_random_color(pastel_factor = pastel_factor)
        if not existing_colors:
            return color
        best_distance = min([color_distance(color,c) for c in existing_colors])
        if not max_distance or best_distance > max_distance:
            max_distance = best_distance
            best_color = color
    return best_color


def main():

    if not op:
        c4d.gui.MessageDialog('Please select object with Selection Tags!')
        return
    
    # Sort only polygon selection tags from all object tags 
    stags = [t for t in op.GetTags() if t.CheckType(c4d.Tpolygonselection)]

    if not stags:
        c4d.gui.MessageDialog('Please select object with Selection Tags!')
        return

    colors = list()
    doc.StartUndo()
    
    for stag in stags:

        name = stag.GetName()
        mat = c4d.Material(c4d.Mbase)
        mat.SetName(name)

        color = generate_new_color(colors)
        colors.append(color)

        mat[c4d.MATERIAL_COLOR_COLOR] = c4d.Vector(*color)
        doc.InsertMaterial(mat)
        doc.AddUndo(c4d.UNDOTYPE_NEWOBJ,mat)

        mtag = op.MakeTag(c4d.Ttexture,stag)
        mtag.SetMaterial(mat)
        mtag[c4d.TEXTURETAG_RESTRICTION] = name
        
        doc.AddUndo(c4d.UNDOTYPE_NEWOBJ,mtag)
    
    doc.EndUndo()
    c4d.EventAdd()
    # pprint(colors)

if __name__ == '__main__':
    main()