Every vertex in reach cast three rays: at it and just beside it on each
side, so that a wall turning away there lets the ray past it find what is
behind. Where the vertex's two active edges leave to either side of the
ray, the wall runs across it and the rays beside it only meet those two
edges. Curved walls flattened into centimetre edges are made of such
vertices. Cones keep their exact area (to 1e-9 against the Dart query on
1,200 Pearl, Summit and Lotus defense cones) with half the points; the
Pearl defense sweep's p99 goes from 6.5 ms to 5.1 ms.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>