axiolid_evaluate::surface

Function partials

Source 
pub fn partials(
    surface: &Surface,
    u: Scalar,
    v: Scalar,
) -> GeomResult<(Vec3, Vec3)>
Expand description

Analytic first partial derivatives (∂S/∂u, ∂S/∂v) at (u, v).

Rational B-spline derivatives are evaluated in homogeneous space and projected with the quotient rule. This remains stable when valid imported knot domains have large offsets that make finite-difference steps vanish.