pub fn screw_path(axes: &CoordinateSystem, helix: &Helix) -> GeopResult<Path>Expand description
The path of a screw motion around the axis axes.w() through
axes.origin(): turning from axes.u() as helix says, right-handed —
from u towards v — or left-handed. A profile point (r, z) travels
along the helix of radius r raised by z: the stations and middles of
the path are the control rows of NurbCurve3D::helix (see
helix_rows), exactly on the cylinder, the height within 0.53 % of
the pitch of the true helix. Tapered, the profile moves out as it rises,
each of its points on a cone, as a pipe thread’s does.
Its stations are a0, a1, … and its spans q0, q1, …, each at
most a quarter turn. It never closes: a sweep along it has caps start
and end.