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Knot Diagram Explorer (2D)

Interactive 2D knot-diagram simulator: rotate a projected trefoil or figure-eight knot and watch the drawn crossing count change with viewing angle, while the true crossing-number invariant stays fixed.

Mathematics2DEasy60 FPS📱 Mobile-adapted⇄ 3D version
2d-3d-knot-theory ↗ Open standalone

This 2D simulator draws real closed space curves — a trefoil knot and a figure-eight knot, each from its own parametric formula — as flat knot diagrams, breaking the strand that passes farther from the viewer at every self-crossing so the over/under structure reads correctly. Rotating the projection changes how many crossings the flattened drawing shows, sometimes many more than the minimum, which is exactly the point: the crossing number is defined as the smallest count achievable over every possible projection, so it stays fixed at 3 for the trefoil and 4 for the figure-eight no matter how the curve is turned, while the crossings actually visible on screen keep shifting with the rotation slider.

⚙ Under the hood

Rotate a projected trefoil or figure-eight knot to see how the drawn crossing count shifts with viewing angle while the true crossing-number invariant stays fixed.

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install

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