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#tilingtuesday

9 posts9 participants1 post today

```
library(tidyverse)
library(interp)
x = c(runif(500), 0,0,1,1)
y = c(runif(500), 0,1,0,1)
triangles(tri.mesh(x = x,y = y)) |>
as_tibble() |>
mutate(i=1:n()) |>
rowwise() |>
mutate(tri = list(
tibble(x=x[c(node1,node2,node3,node1)],
y=y[c(node1,node2,node3,node1)]))) |>
unnest('tri') |>
ggplot() +
geom_polygon(aes(x=x,y=y,group=i,fill=i), show.legend=FALSE) +
scale_fill_viridis_c(option='F') +
theme_void()
```

There are 12 ways to replace two of the cells of an L tetromino with diagonal bars of opposite orientations. They form a unique 6×6 square tiling with a single cycle of overlapping perpendicular bars up to the symmetries of the square and swapping the bar orientations.

Dear #TilingTuesday community,

A while ago I implemented a graphical web app folding certain flat shapes to polyhedra: hcschuetz.github.io/polyhedron

A few tilings are included, but I'd like to add more and ask you for contributions.

A compatible tiling should fit with a triangular or a quad grid. I'm particularly (but not only) interested in tilings that are *not* invariant to reflections.

hcschuetz.github.ioPolyhedron Star

I have found a novel family of rep-tiles which produce aperiodic tilings. The prototile is a triangle with smallest side 1 and biggest side 2, the other side is 1 < x <= 2. The family includes one pointed isosceles triangle, the right triangle of angles 30-60-90 (half an equilateral triangle), and other scalene, obtuse or acute, triangles. The first image shows relevant members of the family, the second the substitution rule. The isosceles triangle of the family has another already known aperiodic tiling ( tilings.math.uni-bielefeld.de/ ) which looks the same but is different because there the tile has no reflections, whereas here some tiles are reflected (in the case of the isosceles triangle the reflection makes a difference when applying the substitution). Figure 3 shows the difference between that tessellation and the one proposed here, mine has just four slopes. Last figure shows a zoom into one big instance of the tiling for the right triangle.
#TilingTuesday #tiling #Mathart #geometry #Mathematics