Disclosed is a method for detecting a movable object in a location, when scanning a rigid object in the location by means of a 3D scanner for generating a virtual 3D model of the rigid object, wherein the method comprises: - providing a first surface by scanning the rigid object; - determining a first scan volume related to the first surface; - providing a second surface by scanning the rigid object; - determining a second scan volume related to the second surface; where the first scan volume and the second scan volume are overlapping in an overlapping/common scan volume; - if at least a portion of the first surface and a portion of the second surface are not coincident in the overlapping/common scan volume, then disregard the portion of either the first surface or the second surface in the overlapping/common scan volume which is closest to the focusing optics of the 3D scanner, as this portion of the first surface or second surface represents a movable object which is not part of the rigid object.