const RAY_ONSET: 1.2
Where the filaments begin, in crater radii.
Just outside the continuous deposit, which is what a ray is — the part of
the blanket that flew far enough to land as a streak rather than a sheet. It
is also a cheap early-out, and the term it gates is faded in across it for
the reason radial gives: a gate a term does not reach zero at is a step.