Type 4) form constant: square lattice
Mathematica code:
SquareLattice[t_] :=
Graphics[{
Table[
Rectangle[{i + t, j + t}],
{i, -2, 42, 2}, {j, -2, 42, 2}],
Table[
Rectangle[{i + 1 + t, j + 1 + t}],
{i, -2, 42, 2}, {j, -2, 42, 2}]},
PlotRange -> {{0, 40}, {0, 40}}, ImageSize -> 500]
ListAnimate[
Table[
SquareLattice[t],
{t, 0, .9, .1}]]
f[x_, y_] := {Log[Sqrt[(x)^2 + (y)^2]], ArcTan[x, y]}
ListAnimate[
Table[
ImageTransformation[
SquareLattice[t],
f[#[[1]], #[[2]]] &, DataRange -> {{-Pi, Pi}, {-Pi, Pi}}],
{t, 0, .9, .1}]]