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node crossing census
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Crossing Census (node)List every crossing in a lattice, with the angles the strands leave it at.
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A diagnostic. It draws no shapes and changes nothing. It answers one question: what does the solver actually see in this lattice, crossing by crossing.
Reach for it when Weave comes back with fewer crossings than the picture obviously has, or with defects you cannot account for. The census is the same topology Weave works from, laid out where you can read it.
Like Weave, this node has a Calculate button and does nothing until you press it. The result is parked until you press it again, is not stored in the saved document, and needs the desktop app. The button reads Recalculate once something upstream has moved.
- Calculate (trigger): the button.
- Geometry (any): the lattice, broken at its crossings by Split Curves. Without that pass there are no meetings of ends to count and the census comes back empty.
- Tol (number, editable, 0.001): how close two ends must be to count as the same meeting point. The same meaning as Weave's Tol, with a tighter default, so a census run at the default is stricter than a weave run at its own.
- Crossings (point): one point per crossing found.
- Report (string): the list.
The first line is the count. Then one line per crossing, giving the four directions the strands leave in, and two numbers, pairA and pairB: the angle between each pair of opposite arms.
Those two numbers are the point of the whole node.
- Near 180 means the two arms of that pair really are opposite: the strand runs straight through the crossing, which is what a strand is supposed to do.
- Far from 180 means the arms are skewed round, so what looks like two strands crossing is closer to a pinwheel. A weave can still be solved there, but the shadows will sit oddly, and this is usually the reason.
A crossing missing from the list is more informative still: it means the ends near it did not resolve into one meeting point, which is a Tol problem rather than a drawing problem. Stability Sweep is how you fix that.
The census counts four-end crossings only. Weave is more generous: it also reads an eight-end tangency meeting as a crossing when the eight ends fall into four tight pairs. Those never appear here.
So the two nodes disagreeing is not a bug and is worth knowing how to read: crossings that Weave reports as v8-as-v4 are precisely the ones the census leaves out.
< Previous: Weave | Next: Stability Sweep >
- Weave: what the census is a diagnostic for.
- Stability Sweep: the other diagnostic, and where Tol comes from.
- Split Curves: the pass that has to run before either of them says anything.