Rhomboid span frame

Just a trial run of a new modelling technique for approaching new kinds of shapes. Intended for creating boxy or sharp-angled shapes with ridges which jot out from their edges along the bisectors of the dihedral angles between the shapes' neighbouring surfaces. However, this approach can also be combined with the Shell or Hollow operations to obtain a frame from the edges of a given sharp-angled shape whose spans have a right-angled rhomboid cross-sectional profile rather than a square cross-sectional profile. All edges have a final fillet applied.