+ Real beam_translation = get_beam_translation (me);
+ Real beam_thickness = Beam::get_thickness (me);
+ int beam_count = Beam::get_beam_count (me);
+ Real height_of_beams = beam_thickness / 2
+ + (beam_count - 1) * beam_translation;
+ Real threshold = scm_to_double (scm) + height_of_beams;
+