dynamic - How to create animated snowfall?

Well, the title is self-explanatory. What sorts of snowfall can we generate using Mathematica? There are two options I suggest to consider:

1) Continuous GIF animations with smallest possible number of frames.

2) Dynamic-based animations.

Answer

My simple version using Image:

size = 300;
r = ListConvolve[DiskMatrix[#], 
     RandomInteger[BernoulliDistribution[0.001], {5 size, size}], {1, 1}] & /@ {1.5, 2, 3};

Dynamic[Image[(r[[#]] = RotateRight[r[[#]], #]) & /@ {1, 2, 3}; Total[r[[All, ;; size]]]]]

Update

A slightly prettier version, same basic idea but now with flakes.

flake := Module[{arm},
   arm = Accumulate[{{0, 0.1}}~Join~RandomReal[{-1, 1}, {5, 2}]];
   arm = arm.Transpose@RotationMatrix[{arm[[-1]], {0, 1}}];
   arm = arm~Join~Rest@Reverse[arm.{{-1, 0}, {0, 1}}];
   Polygon[Flatten[arm.RotationMatrix[# \[Pi]/3] & /@ Range[6], 1]]];


snowfield[flakesize_, size_, num_] := 
  Module[{x = 100/flakesize}, 
   ImageData@
    Image[Graphics[{White, 
       Table[Translate[
         Rotate[flake, RandomReal[{0, \[Pi]/6}]], {RandomReal[{0, x}],
           RandomReal[{0, 5 x}]}], {num}]}, Background -> Black, 
      PlotRange -> {{0, x}, {0, 5 x}}], ImageSize -> {size, 5 size}]];

size = 300;


r = snowfield @@@ {{1, size, 500}, {1.5, size, 250}, {2, size, 50}};
Dynamic[Image[(r[[#]] = RotateRight[r[[#]], #]) & /@ {1, 2, 3}; 
  Total[r[[All, ;; size]]]]]

enter image description here

Comments

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Manipulate[ SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, Mesh -> None, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], {n, 0, 1}] I cant' seem to be able to make a filling between two spheres. I've already tried the obvious Filling -> {1 -> {2}} but Mathematica doesn't seem to like that option. Is there any easy way around this or ... Answer There is no built-in filling in SphericalPlot3D . One option is to use ParametricPlot3D to draw the surfaces between the two shells: Manipulate[ Show[SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], ParametricPlot3D[{ r {Sin[t] Cos[1.5 Pi], Sin[t] Sin[1.5 Pi], Cos[t]}, r {Sin[t] Cos[0 Pi], Sin[t] Sin[0 Pi], Cos[t]}}, {r, 1, 2 - n}, {t, 0, Pi}, PlotStyle -> Yellow, Mesh -> {2, 15}]], {n, 0, 1}]

plotting - Plot 4D data with color as 4th dimension

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I have several sigmoidal fits to 3 different datasets, with mean fit predictions plus the 95% confidence limits (not symmetrical around the mean) and the actual data. I would now like to show these different 2D plots projected in 3D as in but then using proper perspective. In the link here they give some solutions to combine the plots using isometric perspective, but I would like to use proper 3 point perspective. Any thoughts? Also any way to show the mean points per time point for each series plus or minus the standard error on the mean would be cool too, either using points+vertical bars, or using spheres plus tubes. Below are some test data and the fit function I am using. Note that I am working on a logit(proportion) scale and that the final vertical scale is Log10(percentage). (* some test data *) data = Table[Null, {i, 4}]; data[[1]] = {{1, -5.8}, {2, -5.4}, {3, -0.8}, {4, -0.2}, {5, 4.6}, {1, -6.4}, {2, -5.6}, {3, -0.7}, {4, 0.04}, {5, 1.0}, {1, -6.8}, {2, -4.7}, {3, -1.

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