10.9.14 HollowFacet



  \begin{texgraph}[name=HollowFacetbis,export=pgf]
  view(-5,5,-2.5,2.5), Marges(0,0,0,0), size(7.5),
  F:=for z in carre(3-3*i,3+3*i,1) do z,0 od,
  theta:=-pi/2,phi:=0, ep:=2,SaveWin(),
  view(-5,0,-2.5,2.5),ChangeWinTo([-5-5*i,5+5*i]),
  DrawFacet(HollowFacet(F,ep), [color:=lightblue]),
  Arrows:=2,Ligne3D([-3+3.25*i,0,(-3+ep/2)+3.25*i,0],0),
  Arrows:=0,Label(-3+ep/4+4*i,"ep/2"),
  RestoreWin(),SaveWin(),
  view(0,5,-2.5,2.5), ChangeWinTo([-5-5*i,5+5*i]),
  DrawFacet(HollowFacet(F,ep+i), [color:=lightblue]),
  Arrows:=2, Ligne3D([3+3.25*i,0,(3-ep)+3.25*i,0],0),
  Arrows:=0,Label(3-ep/2+4*i,"ep"),
  RestoreWin(),
  Label(-2.5-2*i,"mode=0"), Label(2.5-2*i,"mode=1")
  \end{texgraph}

 PIC



(HollowFacet) mode values



  \begin{texgraph}[name=HollowFacet, export=pgf]
  ModelView(central), Marges(0,0,0,0), size(7.5),
  background(full,darkblue),
  P:=Parallelep(M(-2.5,-2.5,-2.5), 5*vecI,
                5*vecJ, 5*vecK), nb:=15,
  Y:=[1,1,0], R:=[1,0,0],
  Build3D(
      for k from 1 to nb do
        P:=HollowFacet(P, 0.25+i, aux),
        C:=((nb-k+1)*R+(k-1)*Y)/nb,
        bdFacet(P, [color:=RgbL(C)]),
        P:=aux, sep3D
      od),
  Display3D()
  \end{texgraph}

 PIC



HollowFacet: example