Crate geomcore 

A pure, standalone geometric kernel for CAD-grade curves and surfaces.

geomcore provides parametric evaluation of elementary curves and surfaces (lines, circles, ellipses, parabolas, hyperbolas, B-splines; planes, cylinders, cones, spheres, tori, B-spline surfaces), rigid transformations, and analytic curve-on-surface parametrization: computing the exact 2D representation of a 3D curve in a surface’s parameter space wherever a closed form exists.

Namespace layout

• The crate root re-exports the placement and value types shared by everything else: Point3D/Point2D, Vector3D/Vector2D, Axis3D/Axis2D, Frame3D/Frame2D, and Transform.
• curves holds the 3D and 2D curve types (curves::Line3D, curves::Circle3D, curves::Ellipse3D, curves::Parabola3D, curves::Hyperbola3D, curves::BSplineCurve3D, curves::Line2D, curves::Circle2D), the curves::Curve3D/ curves::Curve2D enum adaptors, the curves::TrimmedCurve3D/curves::TrimmedCurve2D pieces of a curve over a parameter range (segments, arcs), and the curves::ParametricCurve3D/curves::ParametricCurve2D traits.
• surfaces holds the five elementary analytic surfaces (surfaces::Plane, surfaces::Cylinder, surfaces::Cone, surfaces::Sphere, surfaces::Torus) plus surfaces::BSplineSurface, the surfaces::Surface enum adaptor, and the surfaces::ParametricSurface trait.

Quick start

use geomcore::{Cylinder, Point3D, Vector3D};
use geomcore::curves::Circle3D;

// Evaluate a circle at a single parameter, and over a batch of parameters.
let circle = Circle3D::new(Point3D::ORIGIN, Vector3D::Z, 2.0).unwrap();
let point = circle.eval_point(std::f64::consts::PI / 4.0);
let points = circle.eval_points(&[0.0, 1.0, 2.0]);
assert_eq!(points[0], circle.eval_point(0.0));

// Curve-on-surface parametrization: this circle is coaxial with the
// cylinder, so it has an exact 2D image, a horizontal line in (u, v).
let cylinder = Cylinder::new(Point3D::ORIGIN, Vector3D::Z, 2.0).unwrap();
let pcurve = circle.parametrize_on(&cylinder).unwrap();

Intersections

Intersect is the one entry point for exact intersections. Between two concrete types it returns the pair’s own result, in either order:

use geomcore::{Intersect, PlaneSphereIntersection, Point3D, Vector3D};
use geomcore::surfaces::{Plane, Sphere};

let plane = Plane::new(Point3D::ORIGIN, Vector3D::Z).unwrap();
let sphere = Sphere::new(Point3D::ORIGIN, 2.0).unwrap();
let tol = geomcore::Tolerance::default();
let PlaneSphereIntersection::Circle(circle) = plane.intersect(&sphere, tol) else {
    panic!("expected a circle");
};
assert_eq!(sphere.intersect(&plane, tol), PlaneSphereIntersection::Circle(circle));

Between surfaces::Surface or curves::Curve3D values it returns a general result such as SurfaceIntersection, which reports NotAnalytic for a B-spline or a pair without a closed form; the numeric functions (marching_intersection, intersect_curve_surface, intersect_curve_curve) cover those.

Extending the kernel

New curve or surface types are added by implementing curves::ParametricCurve3D (or curves::ParametricCurve2D) and surfaces::ParametricSurface respectively, without touching the existing dispatch code in curves::Curve3D/surfaces::Surface.

Re-exports

pub use curves::BSplineConstructionError;

pub use curves::BSplineCurve3D;

pub use curves::Circle2D;

pub use curves::Circle3D;

pub use curves::CircleConstructionError;

pub use curves::Curve2D;

pub use curves::Curve3D;

pub use curves::ElementaryCurve;

pub use curves::Ellipse3D;

pub use curves::EllipseConstructionError;

pub use curves::Hyperbola3D;

pub use curves::HyperbolaConstructionError;

pub use curves::InterpParametrization;

pub use curves::Line2D;

pub use curves::Line3D;

pub use curves::LineConstructionError;

pub use curves::Parabola3D;

pub use curves::ParabolaConstructionError;

pub use curves::ParametricCurve2D;

pub use curves::ParametricCurve3D;

pub use curves::ParametrizeError;

pub use curves::PointExtrema2D;

pub use curves::PointExtrema3D;

pub use curves::TrimmedCurve2D;

pub use curves::TrimmedCurve3D;

pub use curves::TrimmedCurveConstructionError;

pub use curves::parametrize_numeric;

pub use frame::Axis2D;

pub use frame::Axis3D;

pub use frame::Frame2D;

pub use frame::Frame3D;

pub use frame::FrameConstructionError;

pub use intersect::intersect_curve_surface;

pub use intersect::marching_intersection;

pub use intersect::CircleCircle2DIntersection;

pub use intersect::CircleCircle3DIntersection;

pub use intersect::CircleConic3DIntersection;

pub use intersect::CircleConicHit;

pub use intersect::CircleSurfaceIntersection;

pub use intersect::ConeConeIntersection;

pub use intersect::ConeCylinderIntersection;

pub use intersect::ConicSurfaceHit;

pub use intersect::ConicSurfaceIntersection;

pub use intersect::CurveCurveExtremum;

pub use intersect::CurveCurveHit;

pub use intersect::CurveSurfaceHit;

pub use intersect::CylinderCylinderIntersection;

pub use intersect::EllipseEllipse3DIntersection;

pub use intersect::EllipseEllipseHit;

pub use intersect::LatitudeRing;

pub use intersect::LineCircle2DIntersection;

pub use intersect::LineCircle3DIntersection;

pub use intersect::LineConic3DIntersection;

pub use intersect::LineConicHit;

pub use intersect::LineLine2DIntersection;

pub use intersect::LineLine3DIntersection;

pub use intersect::LinePlaneIntersection;

pub use intersect::LineQuadricIntersection;

pub use intersect::LineTorusHit;

pub use intersect::LineTorusIntersection;

pub use intersect::PlaneConeIntersection;

pub use intersect::PlaneCylinderIntersection;

pub use intersect::PlanePlaneIntersection;

pub use intersect::PlaneSphereIntersection;

pub use intersect::SphereConeIntersection;

pub use intersect::SphereCylinderIntersection;

pub use intersect::SphereSphereIntersection;

pub use intersect::TorusConeIntersection;

pub use intersect::TorusCylinderIntersection;

pub use intersect::TorusPlaneIntersection;

pub use intersect::TorusSphereIntersection;

pub use intersect::TorusTorusIntersection;

pub use intersect::CurveCurveIntersection;

pub use intersect::CurveSurfaceIntersection;

pub use intersect::InlineList;

pub use intersect::Intersect;

pub use intersect::SurfaceIntersection;

pub use intersect::curve_curve_extrema;

pub use intersect::intersect_curve_curve;

pub use point::Point2D;

pub use point::Point3D;

pub use projection::CurveProjection;

pub use projection::SurfaceProjection;

pub use surfaces::BSplineSurface;

pub use surfaces::Cone;

pub use surfaces::ConeConstructionError;

pub use surfaces::Cylinder;

pub use surfaces::CylinderConstructionError;

pub use surfaces::ElementarySurface;

pub use surfaces::ParametricSurface;

pub use surfaces::Plane;

pub use surfaces::PlaneConstructionError;

pub use surfaces::Sphere;

pub use surfaces::SphereConstructionError;

pub use surfaces::Surface;

pub use surfaces::Torus;

pub use surfaces::TorusConstructionError;

pub use tolerance::Tolerance;

pub use transform::Transform;

pub use vector::Vector2D;

pub use vector::Vector3D;

Modules

curves

Public curve types: lines, conics, and B-spline curves. Public curve types: parametric curves in 2D and 3D built on top of the crate’s placement types (crate::Axis3D/crate::Axis2D, crate::Frame3D/crate::Frame2D).

frame

Axis and frame placement types. Axis and frame placement types: the coordinate systems that curves and surfaces are positioned in.

intersect

Analytic intersection result types. Analytic intersection result types.

point

Points in 2D and 3D space.

projection

Point-projection result types. Point-projection result types.

surfaces

Public surface types: planes, cylinders, cones, spheres, tori, and B-spline surfaces. Public surface types: the five elementary analytic surfaces (plane, cylinder, cone, sphere, torus) plus B-spline surfaces, built on top of the crate’s placement type (crate::Frame3D).

tolerance

Distance and angle tolerances shared by all geometric queries.

transform

Rigid and affine transformations. Rigid and affine transformations of points and vectors.

vector

Vectors in 2D and 3D space.