pub fn build_swept_envelope(
plan: &SweptEnvelope,
) -> Result<Vec<BrepSolid>, KernelRefusal>Expand description
Build the swept union: the APPLE first, then the LEMON where the turn leaves one outside it.
One body for a FULL turn (the lemon is inside the apple) and for a section
merely TANGENT to the axis (there is no lemon); two for a turn under half a
revolution. A turn in [π, 2π) is refused by name — the far lobe then
OVERLAPS the near one and the union is no longer two disjoint revolves.