t * sin (t) = Christmas tree

Posted by & filed under Art, Code, Community, Graphics, Mathematica, Wolfram, Wolfram Language.

Another code sample from Wolfram Community. I noticed that a discussion about programming a lighted Christmas Tree from a simple equation t*Snt[t] became very popular on Reddit. It is connected to a project a programmer developed. I thought how fast we can make it with Wolfram language? Here is the result with slight flickering 😉 Note a very special care needs to be paid to the dimming of the lights at a larger distances, and pretty shadowing.

  • Function s(t, f) is rescaling sampling rate of driving parameter t of parametric curve so points are distributed uniformly. f is basically phase shift.
  • Parameter PD is just average distance between points

This .GIF file has 100 frames. Enjoy! And in the spirit of holidays don’t forget to read: “Happy Holidays”, the Wolfram Language Way

 
PD = .5; s[t_, f_] := t^.6 - f;
 dt[cl_, ps_, sg_, hf_, dp_, f_] := {PointSize[ps], Hue[cl, 1, .6 + sg .4 Sin[hf s[t, f]]], 
                                     Point[{-sg s[t, f] Sin[s[t, f]], -sg s[t, f] Cos[s[t, f]], dp + s[t, f]}]};
 frames = ParallelTable[

    Graphics3D[Table[{dt[1, .01, -1, 1, 0, f], dt[.45, .01, 1, 1, 0, f], 
                      dt[1, .005, -1, 4, .2, f], dt[.45, .005, 1, 4, .2, f]}, {t, 0, 200, PD}],

     ViewPoint -> Left, BoxRatios -> {1, 1, 1.3}, ViewVertical -> {0, 0, -1}, 
    ViewCenter -> {{0.5, 0.5, 0.5}, {0.5, 0.55}}, Boxed -> False, 
    PlotRange -> {{-20, 20}, {-20, 20}, {0, 20}}, Background -> Black],

   {f, 0, 1, .01}];

Export["tree.gif", frames]

Sin Tree

And from Silvia Hao comes improved version:

 
PD = .5;
 s[t_, f_] := t^.6 - f
 dt[cl_, ps_, sg_, hf_, dp_, f_, flag_] :=
  Module[{sv, basePt},
         {PointSize[ps],
          sv = s[t, f];
          Hue[cl (1 + Sin[.02 t])/2, 1, .3 + sg .3 Sin[hf sv]],
          basePt = {-sg s[t, f] Sin[sv], -sg s[t, f] Cos[sv], dp + sv};
          Point[basePt],
         If[flag,
            {Hue[cl (1 + Sin[.1 t])/2, 1, .6 + sg .4 Sin[hf sv]], PointSize[RandomReal[.01]],
             Point[basePt + 1/2 RotationTransform[20 sv, {-Cos[sv], Sin[sv], 0}][{Sin[sv], Cos[sv], 0}]]},
            {}]
        }]

frames = ParallelTable[
                       Graphics3D[Table[{
                                         dt[1, .01, -1, 1, 0, f, True], dt[.45, .01, 1, 1, 0, f, True],
                                         dt[1, .005, -1, 4, .2, f, False], 
                                         dt[.45, .005, 1, 4, .2, f, False]},
                                        {t, 0, 200, PD}],
                                  ViewPoint -> Left, BoxRatios -> {1, 1, 1.3}, 
                                  ViewVertical -> {0, 0, -1},
                                  ViewCenter -> {{0.5, 0.5, 0.5}, {0.5, 0.55}}, Boxed -> False,
                                  PlotRange -> {{-20, 20}, {-20, 20}, {0, 20}}, Background -> Black],
                       {f, 0, 1, .01}];

Export["tree.gif", frames]

Sin Tree 2

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