Geolis

Geolis

Geolis is a CAD kernel written in Rust. It provides geometry representation using NURBS curves and surfaces, along with B-rep structures for solid modeling.

Features

• NURBS Curves & Surfaces: Mathematically precise freeform geometry representation
• B-rep Structure: Topology management with Vertex, Edge, Face, Shell, and Solid
• Boolean Operations: Solid operations including Union, Difference, and Intersection
• Fast & Safe: Built in Rust, can run in browsers via WebAssembly

Installation

[dependencies]
geolis = "0.1"

Capabilities

NURBS Curves

Generation

Function	Description
NurbsCurve::new	Create curve from control points, knots, and weights
NurbsCurve::interpolate	Generate interpolating curve through point sequence
NurbsCurve::from_arc	Create NURBS curve from arc
NurbsCurve::from_circle	Create NURBS curve from circle
NurbsCurve::periodic	Create closed periodic curve

Evaluation

Function	Description
evaluate	Get point at parameter value
derivative	Get nth derivative vector
tangent	Tangent vector (normalized)
curvature	Curvature value
curvature_vector	Curvature vector
torsion	Torsion (3D curves)

Analysis

Function	Description
closest_point	Find closest point on curve to given point
arc_length	Calculate arc length
parameter_at_length	Inverse: get parameter from arc length
divide_by_count	Get equally divided points
divide_by_length	Divide by equal arc length

Operations

Function	Description
split	Split at specified parameter
trim	Trim to range
reverse	Reverse direction
join	Join two curves
offset	Generate offset curve
insert_knot	Knot insertion (Boehm algorithm)
elevate_degree	Degree elevation

Curve-Curve Operations

Function	Description
intersect	Intersection points between curves
fillet	Generate fillet curve

NURBS Surfaces

Generation

Function	Description
NurbsSurface::new	Create surface from control point grid
NurbsSurface::extrude	Extrude curve to create surface
NurbsSurface::loft	Create surface from multiple curves
NurbsSurface::revolve	Revolve curve to create surface
NurbsSurface::sweep	Sweep cross-section along rail curve
NurbsSurface::ruled	Ruled surface between two curves
NurbsSurface::from_sphere	Sphere surface
NurbsSurface::from_cylinder	Cylinder surface
NurbsSurface::from_cone	Cone surface
NurbsSurface::from_torus	Torus surface

Evaluation

Function	Description
evaluate	Get point at (u, v) parameters
normal	Normal vector
partial_derivative	Partial derivatives
gaussian_curvature	Gaussian curvature
mean_curvature	Mean curvature
principal_curvatures	Principal curvatures

Extraction

Function	Description
isocurve_u	Isocurve at fixed u
isocurve_v	Isocurve at fixed v
boundary_curves	Boundary curves (4 edges)

Operations

Function	Description
trim	Trim surface with trim curves
split_u / split_v	Split at specified parameter
reverse_u / reverse_v	Reverse direction
transpose	Swap u and v directions

Surface-Surface Operations

Function	Description
intersect_surface	Intersection curve between surfaces
intersect_curve	Intersection points of surface and curve

B-rep Structure

Topology Elements

Element	Description
Vertex	Vertex (3D coordinate)
Edge	Edge (curve + start/end vertices)
Loop	Boundary loop (chain of Edges)
Face	Face (surface + boundary loops)
Shell	Shell (collection of Faces)
Solid	Solid (collection of Shells)

Topology Operations

Function	Description
adjacent_faces	Faces adjacent to specified face
adjacent_edges	Edges connected to specified vertex
is_manifold	Check if manifold
is_closed	Check if shell is closed
euler_characteristic	Euler characteristic

Boolean Operations

Function	Description
union	Union
difference	Difference (hole creation)
intersection	Intersection (common part)

Tessellation

Function	Description
tessellate	Convert surface to mesh
TessellationOptions::tolerance	Tolerance
TessellationOptions::adaptive	Adaptive subdivision based on curvature
TessellationOptions::max_divisions	Maximum divisions

Module Structure

geolis
├── geolis-math       # Math utilities
├── geolis-curve      # NURBS curves
├── geolis-surface    # NURBS surfaces
├── geolis-topology   # B-rep structure
├── geolis-boolean    # Boolean operations
├── geolis-mesh       # Tessellation
└── geolis-io         # File I/O

License

MIT License

Links

• Documentation
• Repository