Geometer

Focused C++ geometry library, CLI, Python package, and WASM interface built on OCCT. Geometer provides generic CAD/kernel operations for STEP-to-GLB conversion, STEP HLR projection, exact planar STEP synthesis, planar contouring, and packed planar boolean work.

Documentation

• Developer guide
• Design and interface docs
• Requirements
• ADRs
• Examples

Build And Validate

cmake --preset default
cmake --build build --config Release
python scripts/validate_native.py
python scripts/validate_python_package.py

Native artifacts are copied to dist/native/<platform>/. Root-level dist/geometer* artifacts are intentionally not produced.

Build WASM artifacts:

python scripts/build_wasm.py

WASM artifacts are copied to:

• dist/wasm/browser/
• dist/wasm/node-test/
• dist/wasm/planar-browser/

Python Package

PyPI distribution: wn-geometer

Import package: geometer

Install the current release:

python -m pip install wn-geometer==2026.5.25

Basic Python use:

from pathlib import Path
import geometer

version = geometer.version()
projection = geometer.project_step_hlr(
    Path("part.step"),
    views=[geometer.ProjectionView.top()],
)
glb_bytes = geometer.step_to_glb(Path("part.step"))
step_bytes = geometer.planar_step(
    {
        "schema": "geometry.planar_step.request.a0",
        "units": "mm",
        "bodies": [
            {
                "id": "copper",
                "thickness_mm": 0.035,
                "regions": [
                    {
                        "outer": {
                            "points": [[0, 0], [10, 0], [10, 5], [0, 5]],
                            "segments": [{"kind": "line"}] * 4,
                        }
                    }
                ],
            }
        ],
    }
)
geometer.write_planar_step(
    {
        "schema": "geometry.planar_step.request.a0",
        "units": "mm",
        "bodies": [
            {
                "id": "copper",
                "thickness_mm": 0.035,
                "fuse_regions": True,
                "regions": [
                    {
                        "outer": {
                            "points": [[0, 0], [10, 0], [10, 5], [0, 5]],
                            "segments": [{"kind": "line"}] * 4,
                        }
                    }
                ],
            }
        ],
    },
    "layer.step",
)

The package is executable-backed. Wheels bundle the platform executable under geometer/native/<platform>/, expose a geometer console command in the install environment, and call the executable through the JSON batch CLI.

CLI

geometer --version
geometer step-to-glb input.step output.glb
geometer step-project-hlr input.step output.json
geometer step-project-svg input.step output.svg --mode simple --view top
geometer planar-step planar-step-request.json output.step
geometer init-request request.json --step input.step --operation step_hlr_projection_json --output output.json
geometer run request.json response.json

Examples

• examples/python/step_hlr_svg.py - no-GUI package example that writes HLR projection JSON, SVG, and GLB outputs.
• examples/python/pyvista_hlr_viewer.py - PyVista/Qt STEP 3D + HLR preview.
• examples/wasm/embedded_model_viewer.html - browser viewer using prepared GLB fixtures and the WASM HLR worker.
• examples/cpp/ - native Dear ImGui + SDL3 + OpenGL HLR preview.

Serve browser examples from the repo root:

python -m http.server 8123 --bind 127.0.0.1

Open http://127.0.0.1:8123/examples/wasm/embedded_model_viewer.html.

Release

Geometer uses date-based releases per ADR 006:

• Git tag: vYYYY-MM-DD
• PyPI/CMake version: YYYY.M.D
• C ABI generation: YYYYMMDD

Same-day follow-up releases append a serial to the tag and package version, for example v2026-05-24-2 and 2026.5.24.2. The C ABI generation stays at YYYYMMDD unless the C ABI generation itself changes.

Before tagging, run the L99 release gate plus native and package validation:

python -m pytest tests/L99_release -q
python scripts/validate_native.py
python scripts/validate_python_package.py