Struct NurbsSurface 

pub struct NurbsSurface {
    pub degree_u: usize,
    pub degree_v: usize,
    pub knots_u: Vec<f64>,
    pub knots_v: Vec<f64>,
    pub control_points: Vec<Vec<Vec4>>,
    /* private fields */
}

Fields

degree_u: usize

degree_v: usize

knots_u: Vec<f64>

knots_v: Vec<f64>

control_points: Vec<Vec<Vec4>>

Implementations

impl NurbsSurface

pub fn new( degree_u: usize, degree_v: usize, knots_u: Vec<f64>, knots_v: Vec<f64>, control_points: Vec<Vec<Vec4>>, ) -> Result<Self, String>

pub fn closed_directions(&self) -> Result<(bool, bool), String>

Whether the surface joins itself along u (first) and v (second): opposite domain edges coincide at three sampled fractions. The 1e-6 threshold matches the historical LINEAR_TOLERANCE * 10 used by the projection and curve×surface intersection modules.

pub fn domain_u(&self) -> Result<[f64; 2], String>

pub fn domain_v(&self) -> Result<[f64; 2], String>

pub fn analytic(&self) -> Option<&AnalyticSurface>

The recognized analytic carrier, if this exact rational patch is a plane or a full revolution quadric/torus. Computed once per instance.

pub fn evaluate_homogeneous(&self, u: f64, v: f64) -> Result<Vec4, String>

pub fn evaluate(&self, u: f64, v: f64) -> Result<Vec3, String>

pub fn evaluate_extended(&self, u: f64, v: f64) -> Result<Vec3, String>

Value beyond the domain (Golovanov §3.15): closed directions wrap cyclically; open directions extend along the boundary tangent plane, with the bilinear corner form when both parameters are outside. Intersection and projection algorithms probe outside the domain, so this is a required capability of every surface.

pub fn derivatives_extended( &self, u: f64, v: f64, derivative_count: usize, ) -> Result<Vec<Vec<Vec3>>, String>

Derivatives beyond the domain (§3.15). The extension is C¹: first derivatives follow the ruled/bilinear extension, second derivatives are taken at the boundary anchor (zero across an extended direction).

pub fn derivatives( &self, u: f64, v: f64, derivative_count: usize, ) -> Result<Vec<Vec<Vec3>>, String>

pub fn normal(&self, u: f64, v: f64) -> Result<Vec3, String>

pub fn principal_curvatures(&self, u: f64, v: f64) -> Result<(f64, f64), String>

Principal curvatures (κ_min, κ_max) at (u, v), signed with respect to the parametrization normal n = Su × Sv / |Su × Sv| via the shape operator I⁻¹·II. Convention check: a cylinder of radius R whose normal points AWAY from the axis has κ = −1/R along the circular direction, so an offset’s regularity factor 1 − d·κ vanishes exactly when an inward offset (d = −R) reaches the axis.

pub fn is_affine(&self) -> Result<bool, String>

Whether this is a genuinely affine degree-1 by degree-1 patch.

A tapered bilinear patch is planar but not affine, so degree alone is insufficient for exact inverse-parameter and integration shortcuts.

pub fn iso_curve_u(&self, u: f64) -> Result<NurbsCurve, String>

pub fn iso_curve_v(&self, v: f64) -> Result<NurbsCurve, String>

Trait Implementations

impl Clone for NurbsSurface

fn clone(&self) -> NurbsSurface

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for NurbsSurface

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for NurbsSurface

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for NurbsSurface

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.