I want to visualize a 3D nonplanar pretzel using a closed cubic B-spline displayed with Tube.

I'm just absolutely lost on the whole thing. The closest pretzel shape I've been able to make was using this:

  ParametricPlot3D[{(3 + Sin[x/2])*Cos[x], (3 + Sin[x/2])*Sin[x], 2 Cos[x/2]}, 
    {x, 0, 15}] 
    Line -> (Tube[#, 0.4] &), 
  PlotRange -> All]

But that's not using a B-spline, and I can't seem to find any documentation on creating 3D objects with a B-spline and Tube.


closed as unclear what you're asking by user9660, RunnyKine, MarcoB, Sjoerd C. de Vries, Yves Klett Apr 25 '16 at 9:32

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I put together documentation and this question (for the number of points needed):

 Tube[BSplineCurve[{{-1, 0, 1}, {3, 2, 1}, {0, -2, 1}, {-3, 2, 1}, {1,
      0, 1}}], 0.05]]

enter image description here

Play with the 5 points until you are satisfied.

  • $\begingroup$ awesome, thanks a bunch $\endgroup$ – Michael Baldwin Apr 28 '16 at 10:34

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