code:

import bpy
import mathutils

def set_origin_to_min_world_bbox(obj):
    if obj.type != 'MESH':
        print(f"{obj.name} is not a mesh object.")
        return

    # Get world-space bounding box corners
    local_bbox_corners = [mathutils.Vector(corner) for corner in obj.bound_box]
    world_bbox_corners = [obj.matrix_world @ corner for corner in local_bbox_corners]

    # Find the minimum X, Y, Z position in world space
    min_corner = mathutils.Vector((
        min(corner.x for corner in world_bbox_corners),
        min(corner.y for corner in world_bbox_corners),
        min(corner.z for corner in world_bbox_corners),
    ))

    # Create a temporary empty at that location
    bpy.ops.object.empty_add(type='PLAIN_AXES', location=min_corner)
    empty = bpy.context.active_object

    # Select only the target object
    bpy.ops.object.select_all(action='DESELECT')
    obj.select_set(True)
    bpy.context.view_layer.objects.active = obj

    # Set origin to empty (i.e., to min_corner)
    bpy.ops.object.origin_set(type='ORIGIN_CURSOR', center='MEDIAN')
    bpy.context.scene.cursor.location = min_corner
    bpy.ops.object.origin_set(type='ORIGIN_CURSOR')

    # Delete the temporary empty
    bpy.data.objects.remove(empty, do_unlink=True)

    print(f"Set origin of {obj.name} to minimum bounding box corner at {min_corner}")

# Example usage
obj = bpy.context.active_object
if obj:
    set_origin_to_min_world_bbox(obj)
else:
    print("No active object selected.")