Blender-TexTools/op_color_from_materials.py

import bpy
import bmesh
import operator
from mathutils import Vector
from collections import defaultdict
from math import pi

from . import utilities_color


class op(bpy.types.Operator):
    bl_idname = "uv.textools_color_from_materials"
    bl_label = "Color Elements"
    bl_description = "Assign a color ID to each mesh material slot"
    bl_options = {'REGISTER', 'UNDO'}

    @classmethod
    def poll(cls, context):
        if not bpy.context.active_object:
            return False

        if bpy.context.active_object not in bpy.context.selected_objects:
            return False

        if len(bpy.context.selected_objects) != 1:
            return False

        if bpy.context.active_object.type != 'MESH':
            return False

        # Only in UV editor mode
        if bpy.context.area.type != 'IMAGE_EDITOR':
            return False

        return True

    def execute(self, context):
        color_materials(self, context)
        return {'FINISHED'}


def color_materials(self, context):
    obj = bpy.context.active_object

    for s in range(len(obj.material_slots)):
        slot = obj.material_slots[s]
        if slot.material:
            utilities_color.assign_slot(obj, s)

    utilities_color.validate_face_colors(obj)


bpy.utils.register_class(op)