(* 3D plot of logarithmic spiral, projected on three planes *)

Needs["Graphics`Graphics3D`"];

Module[ {plot1, plot2, plot3 },
  plot1 =              (* Create basic plot *)
    ParametricPlot3D[
      { .001  Cos[t]Exp[.14 t] ,  .001  Sin[t] Exp[.14t ],   .15 t},
      {t, 1, 20 Pi},
      PlotRange -> {{-2, 6}, {-6, 2}, {2 Pi,  6 Pi}}, 
      BoxStyle -> {GrayLevel[.1], AbsoluteThickness[2]},
      PlotPoints -> 10000, DisplayFunction -> Identity
  ];
  plot2 =          (* Shadow the plot on three planes *)
    Shadow[plot1, DisplayFunction -> Identity, 
      BoxStyle -> {GrayLevel[.9], AbsoluteThickness[2]}
  ];
  plot3 =              (* Color and style the final output *)
      Graphics3D[ {
        Join[{RGBColor[1, .1, 0], AbsoluteThickness[2]}, plot2[[1]][[1]]],
        Join[{RGBColor[0, .8, .7], AbsoluteThickness[2]}, plot2[[1]][[2]]],
        Join[{RGBColor[0, .8, .7], AbsoluteThickness[2]}, plot2[[1]][[3]]],
        Join[{RGBColor[0, .8, .7], AbsoluteThickness[2]}, plot2[[1]][[4]]]
  }];
  Show[plot3, BoxStyle -> {GrayLevel[.8], AbsoluteThickness[1]},
    ViewPoint -> {1.3, -2, 2}, DisplayFunction :> $DisplayFunction
  ]
]