Image split into 9 tiles, driven by the rotating‑squares
auxetic mechanism — pitch l(θ) = a(cos θ + sin θ) —
folds 0° → 90°, settling re‑aligned (tiles turned ±90°)
→ negative Poisson's ratio ν = −1
Opened from the studio, the generated starting image is
projected onto the tiles — refreshed on every new generation.
Append ?img=URL for any picture (data: URIs work too);?pattern=1 for the plain pattern.