如何绘制平行六面体的投影？

Question

我有一张方程组和平行六面体图。

请告诉我，请问如何绘制平行六面体的投影？

l = Plot3D[Sin[x] + Log[y], {x, -1, 3.14}, {y, 1, 6}, 
   PlotStyle -> Opacity[0.7]];
e = Plot3D[Cos[y] + Exp[x] - 3, {x, -1, 3.14}, {y, 1, 6}, 
   ColorFunction -> "DarkRainbow"];
l1 = Graphics3D[{Opacity[0.3], 
    Parallelepiped[{-1, 
      1, -0.85}, {{1, 0, 0}, {0, 1, 0}, {0, 0, 1.6}}]}, Axes -> True];
l2 = Graphics3D[{Opacity[0.3], 
    Parallelepiped[{-1, 
      2, -0.16}, {{1, 0, 0}, {0, 1, 0}, {0, 0, 1.25}}]}, Axes -> True];
l3 = Graphics3D[{Opacity[0.3], 
    Parallelepiped[{-1, 3, 
      0.25}, {{1, 0, 0}, {0, 1, 0}, {0, 0, 1.15}}]}, Axes -> True];
l4 = Graphics3D[{Opacity[0.3], 
    Parallelepiped[{-1, 4, 
      0.55}, {{1, 0, 0}, {0, 1, 0}, {0, 0, 1.05}}]}, Axes -> True];
l5 = Graphics3D[{Opacity[0.3], 
    Parallelepiped[{-1, 5, 0.77}, {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}}]},
    Axes -> True];

l6 = Graphics3D[{Opacity[0.3], 
    Parallelepiped[{0, 1, 
      0.01}, {{0.75, 0, 0}, {0, 1, 0}, {0, 0, 1.35}}]}, Axes -> True];

..........

e1 = Graphics3D[{Opacity[0.3], Green, 
    Parallelepiped[{0.4, 
      1, -0.914}, {{0.97, 0, 0}, {0, 1, 0}, {0, 0, 1.5}}]}, 
   Axes -> True];
e2 = Graphics3D[{Opacity[0.3], Green, 
    Parallelepiped[{1.07, 1, 
      0.586}, {{0.6, 0, 0}, {0, 1, 0}, {0, 0, 1.5}}]}, Axes -> True];
e3 = Graphics3D[{Opacity[0.3], Green, 
    Parallelepiped[{1.48, 1, 
      2.086}, {{0.33, 0, 0}, {0, 1, 0}, {0, 0, 0.76}}]}, Axes -> True];

..........

Show[l, l1, l2, l3, l4, l5, l6, l7, l8, l9, l10, l11, l12, l13, l14, 
  l15, l16, l17, l18, l19, l20, l21, l22, l23, l24, l25];
Show[l, e, e1, e2, e3, e4, e5, e6, e7, e8, e9, e10, e11, e12, e13, 
  e14, e15];

Show[l, l1, l2, l3, l4, l5, l6, l7, l8, l9, l10, l11, l12, l13, l14, \
l15, l16, l17, l18, l19, l20, l21, l22, l23, l24, l25, e, e1, e2, e3, \
e4, e5, e6, e7, e8, e9, e10, e11, e12, e13, e14, e15]
Show[l, e];

这里我绘制了方程式的投影

  ContourPlot[{Cos[y] + Exp[x] - 3 == 0, Sin[x] + Log[y] == 0, 
      Parallelepiped[{0.4, 
        1, -0.914}, {{0.97, 0, 0}, {0, 1, 0}, {0, 0, 1.5}}]}, {x, -1, 
      Pi}, {y, -5, Pi}]