Crate ifc_lite_geometry 

IFC-Lite Geometry Processing

Efficient geometry processing for IFC models using earcutr triangulation and nalgebra for transformations.

Overview

This crate transforms IFC geometry representations into GPU-ready triangle meshes:

• Profile Handling: Extract and process 2D profiles (rectangle, circle, arbitrary)
• Extrusion: Generate 3D meshes from extruded profiles
• Triangulation: Polygon triangulation with hole support via earcutr
• CSG Operations: Full boolean operations (difference, union, intersection)
• Mesh Processing: Normal calculation and coordinate transformations

Supported Geometry Types

Type	Status	Description
IfcExtrudedAreaSolid	Full	Most common - extruded profiles
IfcFacetedBrep	Full	Boundary representation meshes
IfcTriangulatedFaceSet	Full	Pre-triangulated (IFC4)
IfcBooleanClippingResult	Full	CSG operations (difference, union, intersection)
IfcMappedItem	Full	Instanced geometry
IfcSweptDiskSolid	Full	Pipe/tube geometry

Quick Start

use ifc_lite_geometry::{
    Profile2D, extrude_profile, triangulate_polygon,
    Point2, Point3, Vector3
};

// Create a rectangular profile
let profile = Profile2D::rectangle(2.0, 1.0);

// Extrude to 3D
let direction = Vector3::new(0.0, 0.0, 1.0);
let mesh = extrude_profile(&profile, direction, 3.0)?;

println!("Generated {} triangles", mesh.triangle_count());

Geometry Router

Use the GeometryRouter to automatically dispatch entities to appropriate processors:

use ifc_lite_geometry::{GeometryRouter, GeometryProcessor};

let router = GeometryRouter::new();

// Process entity
if let Some(mesh) = router.process(&decoder, &entity)? {
    renderer.add_mesh(mesh);
}

Performance

• Simple extrusions: ~2000 entities/sec
• Complex Breps: ~200 entities/sec
• Boolean operations: ~20 entities/sec

Re-exports

pub use bool2d::compute_signed_area;

pub use bool2d::ensure_ccw;

pub use bool2d::ensure_cw;

pub use bool2d::is_valid_contour;

pub use bool2d::point_in_contour;

pub use bool2d::subtract_2d;

pub use bool2d::subtract_multiple_2d;

pub use bool2d::union_contours;

pub use csg::calculate_normals;

pub use csg::ClippingProcessor;

pub use csg::Plane;

pub use csg::Triangle;

pub use error::Error;

pub use error::Result;

pub use extrusion::extrude_profile;

pub use extrusion::extrude_profile_with_voids;

pub use mesh::CoordinateShift;

pub use mesh::Mesh;

pub use mesh::SubMesh;

pub use mesh::SubMeshCollection;

pub use processors::AdvancedBrepProcessor;

pub use processors::BooleanClippingProcessor;

pub use processors::ExtrudedAreaSolidProcessor;

pub use processors::FaceBasedSurfaceModelProcessor;

pub use processors::FacetedBrepProcessor;

pub use processors::MappedItemProcessor;

pub use processors::PolygonalFaceSetProcessor;

pub use processors::RevolvedAreaSolidProcessor;

pub use processors::SurfaceOfLinearExtrusionProcessor;

pub use processors::SweptDiskSolidProcessor;

pub use processors::TriangulatedFaceSetProcessor;

pub use profile::Profile2D;

pub use profile::Profile2DWithVoids;

pub use profile::ProfileType;

pub use profile::VoidInfo;

pub use profiles::ProfileProcessor;

pub use router::GeometryProcessor;

pub use router::GeometryRouter;

pub use transform::apply_rtc_offset;

pub use transform::parse_axis2_placement_3d;

pub use transform::parse_axis2_placement_3d_from_id;

pub use transform::parse_cartesian_point;

pub use transform::parse_cartesian_point_from_id;

pub use transform::parse_direction;

pub use transform::parse_direction_from_id;

pub use triangulation::triangulate_polygon;

pub use void_analysis::classify_voids_batch;

pub use void_analysis::extract_coplanar_voids;

pub use void_analysis::extract_nonplanar_voids;

pub use void_analysis::VoidAnalyzer;

pub use void_analysis::VoidClassification;

pub use void_index::VoidIndex;

pub use void_index::VoidStatistics;

Modules

bool2d

2D Boolean Operations for Profile-Level Void Subtraction

csg

CSG (Constructive Solid Geometry) Operations

error

extrusion

Extrusion operations - converting 2D profiles to 3D meshes

mesh

Mesh data structures

processors

Geometry Processors - P0 implementations

profile

2D Profile definitions and triangulation

profiles

Profile Processors - Handle all IFC profile types

router

Geometry Router - Dynamic dispatch to geometry processors

transform

Shared transform utilities for IFC geometry processing

triangulation

Polygon triangulation utilities

void_analysis

Void Analysis Module

void_index

Void Index Module

Type Aliases

Point2

A statically sized 2-dimensional column point.

Point3

A statically sized 3-dimensional column point.

Vector2

A stack-allocated, 2-dimensional column vector.

Vector3

A stack-allocated, 3-dimensional column vector.