Blender Addon to setup Unity LOD variations

unity_lod_setup.py

bl_info = {
    "name": "Unity LOD Setup",
    "blender": (3, 0, 0),
    "category": "Object",
}

import bpy


class SetupUnityLOD(bpy.types.Operator):
    """Setup Unity LOD"""
    bl_idname = "object.setup_unity_lod"
    bl_label = "Setup Unity LOD"
    bl_options = {'REGISTER', 'UNDO'}

    def duplicate(self, object):
        duplicated_object = object.copy()
        object.users_collection[0].objects.link(duplicated_object)
        return duplicated_object

    def execute(self, context):
        scene = context.scene
        object = context.active_object

        if object is None:
            return {'FINISHED'}

        name = bpy.path.basename(bpy.context.blend_data.filepath).removesuffix('.blend')
        if object.users_collection[0].name.startswith('export-'):
            sub_name = object.users_collection[0].name[7:]
            name = f'{name}-{sub_name}'

        context.view_layer.objects.active = object
        for i in [0, 1, 2]:
            lod = self.duplicate(object) if i > 0 else object
            lod.name = f'{name}_LOD{i}'
            decimate = lod.modifiers.get('LOD-Decimate') or lod.modifiers.new('LOD-Decimate', 'DECIMATE')
            decimate.decimate_type = 'COLLAPSE'
            decimate.use_collapse_triangulate = True
            decimate.ratio = 1 / (2 ** i)

        return {'FINISHED'}


def menu_func(self, context):
    self.layout.operator(SetupUnityLOD.bl_idname)


def register():
    bpy.utils.register_class(SetupUnityLOD)
    bpy.types.VIEW3D_MT_object.append(menu_func)  # Adds the new operator to an existing menu.


def unregister():
    bpy.utils.unregister_class(SetupUnityLOD)