This makes a simple parametric surface:

surface = 
 ParametricPlot3D[{Cos[u], Sin[u], v}, {u, 0, 2 \[Pi]}, {v, 0, 1}]

This exports it in Maya format:

Export["cylinder", surface, "Maya"]

And this exports it in 3DS format:

Export["cylinder.3ds", surface, "3DS"]

I can't say why the example you gave didn't export. If you post the expression that created the surface, I can take a look.

Chris

Here is the code:

Manipulate[
 Module[{\[CurlyEpsilon] = 10^-6, c1 = Tan[a1], c2 = Tan[a2], 
   c3 = Tan[a3], c4 = Tan[a4], c5 = Tan[a5], c6 = Tan[a6]}, 
  ContourPlot3D[
   Evaluate[
    c6 Sin[3 x] Sin[2 y] Sin[z] + c4 Sin[2 x] Sin[3 y] Sin[z] + 
      c5 Sin[3 x] Sin[y] Sin[2 z] + c2 Sin[x] Sin[3 y] Sin[2 z] + 
      c3 Sin[2 x] Sin[y] Sin[3 z] + c1 Sin[x] Sin[2 y] Sin[3 z] == 
     0], {x, \[CurlyEpsilon], 
    Pi - \[CurlyEpsilon]}, {y, \[CurlyEpsilon], 
    Pi - \[CurlyEpsilon]}, {z, \[CurlyEpsilon], Pi - \[CurlyEpsilon]},
    Mesh -> False, ImageSize -> {400, 400}, Boxed -> False, 
   Axes -> False, NormalsFunction -> "Average", 
   PlotPoints -> ControlActive[10, 30], 
   PerformanceGoal -> "Speed"]], {{a1, 1, 
   "\!\(\*SubscriptBox[\(\[Alpha]\), \(1\)]\)"}, -Pi/2 - 0.01, 
  Pi/2 + 0.01, 
  ImageSize -> Tiny}, {{a2, 1, 
   "\!\(\*SubscriptBox[\(\[Alpha]\), \(2\)]\)"}, -Pi/2 - 0.01, 
  Pi/2 + 0.01, 
  ImageSize -> Tiny}, {{a3, 1, 
   "\!\(\*SubscriptBox[\(\[Alpha]\), \(3\)]\)"}, -Pi/2 - 0.01, 
  Pi/2 + 0.01, 
  ImageSize -> Tiny}, {{a4, 1, 
   "\!\(\*SubscriptBox[\(\[Alpha]\), \(4\)]\)"}, -Pi/2 - 0.01, 
  Pi/2 + 0.01, 
  ImageSize -> Tiny}, {{a5, 1, 
   "\!\(\*SubscriptBox[\(\[Alpha]\), \(5\)]\)"}, -Pi/2 - 0.01, 
  Pi/2 + 0.01, 
  ImageSize -> Tiny}, {{a6, 1, 
   "\!\(\*SubscriptBox[\(\[Alpha]\), \(6\)]\)"}, -Pi/2 - 0.01, 
  Pi/2 + 0.01, ImageSize -> Tiny}, AutorunSequencing -> {1, 3, 5}, 
 ControlPlacement -> Left]

It is my pleasure to show the "interesting architectural form" if I manage to do it :)

Thankyou :) It worked