corc.frame Namespace Reference

Classes
class	FrameError
class	Frame

Detailed Description

Continuous Frenet-based frame along a Curve.

Algorithm (pinned by the audited plan, refined per the final audit):
- Frenet frame from exact derivatives (t = v/|v|, b = v x a/|v x a|,
  n = b x t) wherever kappa >= KAPPA_TOL.
- Reference-up fallback where kappa < KAPPA_TOL (straight segments), with
  hysteresis so the frame does not chatter at the threshold. The
  Frenet/fallback decision of a query point follows the nearest reference
  sample, so it is piecewise constant in s.
- Sign continuity enforced against a dense precomputed reference sampling:
  n and b flip together so that n stays continuous along s. NOTE: through
  an inflection (kappa -> 0 crossing) this yields a CONTINUOUS frame that
  is deliberately NOT the pure Frenet frame (whose normal would jump);
  what raises FrameError is a rotation between adjacent samples that stays
  above MAX_STEP_ROTATION even after adaptive resampling — i.e. a genuine
  kink, not a smooth inflection.