Taper tolerance for the joint packet gate. The gate opens (building a
packet so the fragment runs the DEFICIT rule instead of the cheap hard
cut) when ANY of four conditions defeats the hard cut's assumption
that the partner covers my foreign side: the legs' radii differ by
more than this fraction (either direction), my own leg widens away
from the joint by more than it, the partner is shorter than twice my
joint radius, or the turn is sharper than 120° (#1495, #1501). Long,
congruent, gentle joints — the overwhelmingly common case and the
fill benchmarks' only case — keep the exact zero-cost partition.
Taper tolerance for the joint packet gate. The gate opens (building a packet so the fragment runs the DEFICIT rule instead of the cheap hard cut) when ANY of four conditions defeats the hard cut's assumption that the partner covers my foreign side: the legs' radii differ by more than this fraction (either direction), my own leg widens away from the joint by more than it, the partner is shorter than twice my joint radius, or the turn is sharper than 120° (#1495, #1501). Long, congruent, gentle joints — the overwhelmingly common case and the fill benchmarks' only case — keep the exact zero-cost partition.