Function offset_point3 

pub fn offset_point3(
    curve: &Curve3,
    distance: Scalar,
    reference_direction: Vec3,
    t: Scalar,
) -> GeomResult<Point3>

The point of the offset by distance along normalise(V x B'(t)) of a 3D curve at its parameter t, V the reference direction.

Errors

The basis’s evaluation errors, and GeomError::Degenerate where its tangent vanishes or lies along V, or V is zero or not finite.