Struct SurfacePoint 

pub struct SurfacePoint {
    pub point: Point,
    pub du: Vector,
    pub dv: Vector,
}

A point on a surface with its first derivatives.

Fields

point: Point

The position.

du: Vector

Derivative along u.

dv: Vector

Derivative along v.

Implementations

impl SurfacePoint

pub fn normal(&self, tol: Tolerances) -> OgeomResult<Direction>

The unit normal, du x dv normalized.

Errors

OgeomError::Construction at a degeneracy (a sphere’s pole or a cone’s apex), where no normal is determined by the tangents.

pub fn is_degenerate(&self, tol: Tolerances) -> bool

Whether the tangents fail to determine a normal.

Compared against the square of the larger tangent, not against the product of the two. The product test asks whether the tangents are collinear, which is only one of the two ways a surface degenerates: at a sphere’s pole or a cone’s apex one tangent vanishes, and there the product is itself near zero, so a relative-to-product test finds the cross product respectably large by comparison and declares the point healthy. Squaring the larger tangent keeps a fixed scale to judge against and catches both cases.

Trait Implementations

impl Clone for SurfacePoint

fn clone(&self) -> SurfacePoint

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SurfacePoint

impl Debug for SurfacePoint

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

Formats the value using the given formatter.

impl PartialEq for SurfacePoint

fn eq(&self, other: &SurfacePoint) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for SurfacePoint