(* Mathematica program for front illustration *)

c  = Sqrt[1/3] ; (* Cos[ half obtuse angle ] *)
s  = Sqrt[2/3] ; (* Sin[ half obtuse angle ] *)
r  = 1 / (20s) ; (* relative beam width *)

a1 = {  c,  0,  s } ;
a2 = {  c,  0, -s } ;
a3 = { -c,  s,  0 } ;
a4 = { -c, -s,  0 } ;

cpr[u_,v_] := (* cross product *)
  { u[[2]] v[[3]] - u[[3]] v[[2]]
  , u[[3]] v[[1]] - u[[1]] v[[3]]
  , u[[1]] v[[2]] - u[[2]] v[[1]] } ;

vee[u_,v_] := (* half a rhombus frame *)
  With[ { m = { u, v, cpr[u,v]/c }
        , p = 1 - r
        , q = 1 + 2r }
      , With[ { u1 = {r,r,r}.m , u2 = {r,r,-r}.m
              , u3 = {p,r,r}.m , u4 = {p,r,-r}.m
              , u5 = {p,p,r}.m , u6 = {p,p,-r}.m
              , u7 = {q,0,0}.m , u8 = {q,q, 0}.m }
            , { Polygon[{ u2, u1, u3, u4 }]
              , Polygon[{ u4, u3, u5, u6 }]
              , Polygon[{ u7, u4, u6, u8 }]
              , Polygon[{ u7, u8, u5, u3 }] }
      ]     ] ;

rmb[u_,v_] := (* rhombus frame *)
  { vee[u,v], vee[v,u] } ;

obj = { rmb[a1,a2], rmb[a1,a3], rmb[a1,a4]
      , rmb[a2,a3], rmb[a2,a4], rmb[a3,a4] } ;

grf = Graphics3D[ obj, Boxed -> False ] ;

Show[ grf, ViewPoint -> { -0.1, -2.4, 0.8 } ]
