∗∗ pm
Parallel mirrors. A colour-reversing mirror pins the contour: w vanishes identically along the line, so the mirror itself is drawn as a black/white boundary. The catalog holds 7 saved fields under a pm film group, read 31 different ways: 7 where the operation s is itself a spacetime symmetry of the wave — so s and the half-period wait are two names for one antisymmetry — 20 where s is free, and 4 plain thresholds to compare them with. Separately measured: 18 of the 31 exchange the two inks after half a period exactly.
1 · The film group
Each tile is a pm film group — the same wallpaper group with a different assignment of time shifts to its operations — and counts the distinct pictures the catalog holds under it. A field filed under more than one film group appears under each.
2 · The rule that makes two colours
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Parameters, thumbnails and the measured two-colour tables are precomputed.
The marks are off on every animation on this site. Tick the box, or press G, to draw the operations of the two-colour group over the picture.
The measured two-colour group — …
| Operation | Wait | Colours | Residual |
|---|
Numerical record
Only pictures whose two-colour law was re-derived from the saved bytes at every node-frame appear here.
All 17 wallpaper groups · The same fields in ember (pm) · Weave Monochrome · Plume Monochrome · Entangled colourings · How the patterns are computed