Omnitruncated
Following up on my earlier permutohedron GIF, the key elements of this GIF are two projections of the permutohedron of order 5, which is a 4-dimensional polytope (in fact, it's the omnitruncated 5-cell...hence the title), which are being linearly interpolated between.
Here's a function for producing the edges of the permutohedron of order n, which naturally sits in the hyperplane in $\mathbb{R}^n$ given by $x_1 + \ldots + x_n = \frac{n(n+1)}{2}$, together with the matrix for projecting out the perpendicular direction:
permutohedronEdges[n_] :=
Select[Subsets[Permutations[Range[n]], {2}],
Or @@ Table[
Position[#[[1]], i] == Position[#[[2]], i + 1] &&
Position[#[[1]], i + 1] == Position[#[[2]], i] &&
And @@ Table[
Position[#[[1]], Mod[i + j, n, 1]] ==
Position[#[[2]], Mod[i + j, n, 1]], {j, 2, n - 1}], {i, 1,
n - 1}] &];
permutohedronProjectionMatrix[n_] :=
Orthogonalize[NullSpace[Transpose[#].#]] &[{ConstantArray[1, n]}];
And the slightly gross Manipulate
for the animation (the use of angles like $\pi/2 + .0001$ is a really inelegant way of avoiding zero-length edges, which gunk up the image with unwanted dots):
Manipulate[Module[{t, cols, rotproj1, rotproj2},
t = 1/2 - (-1)^Floor[s] Cos[π s]/2 + Floor[s];
cols = RGBColor /@ {"#D8FFF1", "#5B73A7"};
rotproj1 =
RotationMatrix[π/2 -
ArcTan[Sqrt[3/5]]].({{Cos[θ], 0, 0, -Sin[θ]}, {0,
0, 1, 0}} /. θ -> π/
2 + .0001).permutohedronProjectionMatrix[5];
rotproj2 = ({{Cos[θ], 0, 0, -Sin[θ]}, {0, 1, 0,
0}} /. θ -> π/
2 - .0001).permutohedronProjectionMatrix[5];
Graphics[{Thickness[.01], cols[[1]], CapForm["Round"],
JoinForm["Round"],
Line /@ ((1 - Min[t, 1]) (rotproj1.# & /@ # & /@
permutohedronEdges[5]) + (1 -
Abs[t - 1]) (rotproj2.# & /@ # & /@
permutohedronEdges[5]) + (Max[t, 1] -
1) ({#[[1]], -#[[2]]} & /@ # & /@ (rotproj1.# & /@ # & /@
permutohedronEdges[5])))}, PlotRange -> 5,
ImageSize -> 540, Background -> cols[[2]]]], {s, 0, 2}]