auto_smooth.py

import bpy
import bmesh
import math


class AutoSmooth(bpy.types.Operator):
    """Turn on Auto Smooth for selected meshes"""
    bl_options = {'REGISTER', 'UNDO'}
    bl_idname = "bedset.auto_smooth"
    bl_label = "Auto Smooth"

    smooth: bpy.props.BoolProperty(
        name="Use Auto Smooth",
        description="Toggle auto smooth on or off",
        default=True,
    )

    angle: bpy.props.FloatProperty(
        name="Angle",
        description="Angle above which to select edges",
        default=math.radians(30),
        min=0,
        max=math.radians(180),
        step=10,
        precision=3,
        subtype='ANGLE',
    )

    @classmethod
    def poll(cls, context):
        return len(context.selected_objects) > 0

    def execute(self, context):
        for o in context.selected_objects:
            if o.type != 'MESH':
                continue

            mesh = o.data
            mesh.use_auto_smooth = self.smooth
            mesh.auto_smooth_angle = self.angle

            if mesh.is_editmode:
                bm = bmesh.from_edit_mesh(mesh)
            else:
                bm = bmesh.new()
                bm.from_mesh(mesh)

            for f in bm.faces:
                f.smooth = True

            if mesh.is_editmode:
                bmesh.update_edit_mesh(mesh)
            else:
                bm.to_mesh(mesh)
                mesh.update()

        return {'FINISHED'}

    def draw(self, context):
        self.layout.prop(self, "smooth")
        self.layout.prop(self, "angle")