Axis of a circular edge: the circle's center plus the unit normal of its
plane. Returns null for non-circular curves.
Derived kernel-agnostically from three sampled points (the circumcenter of a
triangle determines the unique circle through its vertices), so it works for
full circles and arcs alike without an analytic circle accessor.
Axis of a circular edge: the circle's center plus the unit normal of its plane. Returns null for non-circular curves.
Derived kernel-agnostically from three sampled points (the circumcenter of a triangle determines the unique circle through its vertices), so it works for full circles and arcs alike without an analytic circle accessor.