randomize multiple materials to different objects

Question

I found a nice tutorial https://www.youtube.com/watch?v=I6o3Dq6bkn8&list=PL8iHMWPijQzs7RqTZDcXx7mtjMMTKk5es&index=116&ab_channel=Blender

this is to randomise material according a prefix name , so you can take a several materials starting with the same prefix and apply them randomly to several meshes.

how could I apply this script if each mesh use a different prefix. if I have 2 objects and I want to randomise 1 with a prefix and randomise the second one with another prefix in the same script.

I don't know anything about python

import random
import bpy

prefix = '_'

materials = []
for mat in bpy.data.materials:
     if mat.name.startswith(prefix):
         materials.append(mat)

for obj in bpy.context.selected_objects:
     obj.active_material = random.choice(materials)

here is the python script on the youtube tutorial

If anyone has a solution , that ll be great 🙏

Answer 1

You could create a list of prefixes and use a loop to check against them all. (There are other ways but this is easy to explain.) Here's your loop modified:

import random
import bpy

prefixes = ['_', '.']

materials = []
for mat in bpy.data.materials:
    for prefix in prefixes:
         if mat.name.startswith(prefix):
             materials.append(mat)

for obj in bpy.context.selected_objects:
     obj.active_material = random.choice(materials)

You can have as many prefixes in the list on the 4th line as you'd like. You just have to make sure each one is unique.

I used a period in my example. Replace it with whatever you want for your second prefix.