kernel::sew builds an arc edge, and the wall an extruded arc sweeps, with truck's
three-point arc (circumcentre, then a turn about it). On a very flat arc that
construction ends off its own vertex: a 12 mm chord with a 0.08 um sagitta (a 225 m
radius) ends about 1e-6 mm short of it, and the planar face holding the arc, 1238 mm
from the origin, fails with "cannot attach a plane to a wire that is not on one plane".
truck's plane fit takes the sum of the wire's control points as its centre, so a gap
of that size is scaled by a distance of the order of the coordinates and tilts the
estimated normal beyond the fit's 1e-6 flatness tolerance.
Arcs whose sagitta is under 1% of the half chord are now built as their exact rational
quadratic (apex 2/(1-t^2) along the bow, weight (1-t^2)/(1+t^2), t the sagitta over the
half chord), for edges and for the extruded walls on them. Deeper arcs keep truck's
construction.
Co-authored-by: NOWN-DEV <257771410+NOWN-DEV@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
A sheet-metal tray built at 2000 x 2500 mm with an edge flange on all four
edges (72° or 90°) and unfolded failed to rebuild when W and H went to
400 x 300, 600 x 450, or W alone to 400: "planar region arrangement failed
or exceeded its bounded processing budget". The same tray drawn at 400 x 300
unfolded, and growing it worked.
The sketch solved again after the change leaves its corners ~1e-13 mm off,
so the flanges inherit a hair of tilt and their panels and bend zones meet
the trimmed base within 1e-13 mm instead of exactly. The flat pattern is a
balanced union of those pieces, and the arrangement chains its output loops
within 10 tol. In a later round, ray parity classified a bend zone's edge
midpoint that lay level with a corner whose two lines did not quite meet:
the ray slipped through the gap without a crossing, the zone's edges counted
as inside the other operand and were dropped, and the outline no longer
closed. A rectangle turned by 1e-14 rad failed the same way.
inside_loop now closes the gap where one line ends and the next begins with
a straight connector while it counts crossings; exactly closed joints are
unaffected. Joints with an arc keep the arc's own endpoint rule, which
treats ends within its angular tolerance as on the ray (a connector there
double counted at a circle split into two arcs).
Co-authored-by: NOWN-DEV <257771410+NOWN-DEV@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
