Native Elixir geometry, powered by Open CASCADE Technology.
OCEx provides immutable, immediate geometry operations through a C++ NIF linked to OCCT 7.9.3. Create solids, build profiles, combine and finish bodies, inspect their topology, and exchange STEP, BREP, or STL. No Python runtime or runtime Hex dependencies are required.
For deferred pipelines, workplanes, named assemblies, Livebook previews, and verified STL/3MF bundles, use Smith. OCEx is the lower layer and can be used independently.
A first solid
Install the native prerequisites using the installation guide,
then save this as plate.exs:
Mix.install([{:ocex, "~> 0.1.0"}])
{:ok, blank} = OCEx.box(60, 40, 5)
{:ok, bore} = OCEx.cylinder(4, 7)
{:ok, bore} = OCEx.translate(bore, {30, 20, -1})
{:ok, plate} = OCEx.cut(blank, bore)
{:ok, true} = OCEx.valid?(plate)
{:ok, volume} = OCEx.volume(plate)
{:ok, :ok} = OCEx.write_step(plate, "plate.step")
{:ok, :ok} = OCEx.write_stl(plate, "plate.stl", 0.03, 0.5)
IO.puts("Plate volume: #{volume} mm³")Run elixir plate.exs. For a Mix application, add {:ocex, "~> 0.1.0"} to its
dependencies. Mix builds the NIF automatically. The exact OCCT toolkit must remain
installed at runtime because the NIF dynamically links its libraries.
What is included
| Area | Operations |
|---|---|
| Solids | Box, cylinder, sphere, cone, ring torus |
| Profiles | Lines, circles, directed arcs, interpolated splines, wires, planar faces |
| Modeling | Extrusion, revolution, ruled/smooth loft, sweep, shelling, split, section, draft, sewing, offset, thickening, compound, union, subtraction, intersection |
| Finishing | Fillet, chamfer, same-domain cleanup |
| Placement | Translation, axis-angle rotation, planar mirror, uniform scale |
| Inspection | Topology, validity, bounds, volume, area, length, centroids, curve/surface information |
| Exchange | BREP snapshots, STEP import/export, binary STL export, indexed surface mesh |
See the OCEx module for each function's contract and the
native geometry guide for units, orientation,
profile requirements, selectors, meshing, and exchange behavior.
A small, explicit contract
Every public operation returns {:ok, value} or {:error, reason}. Shapes are
opaque, garbage-collected native resources. Modeling operations preserve their
inputs; edge selections belong to one exact shape revision. Coordinates are
{x, y, z} tuples, examples use millimeters, and modeling angles use degrees.
Mesh angular deflection uses radians.
OCEx covers the operations needed by Smith, not the full OCCT API. Calls run on BEAM dirty schedulers and are serialized for predictable native ownership. In-process native faults can crash the VM, and kernel operations cannot be forcibly cancelled by terminating an Elixir process. Read errors and lifetimes before integrating a service.
Documentation and development
- Installation and deployment
- Geometry and exchange
- Errors, ownership, and execution
- Changelog
- Repository and test workflow
The suite exercises the real kernel with analytic measurements, topology checks, file round trips, invalid inputs, resource lifetimes, and concurrency. The source installer pins and checksums OCCT; release checks build isolated consumers from package archives.
OCEx is MIT licensed. Open CASCADE Technology has its own license and exception. The installer applies a documented allocator-alignment patch to OCCT 7.9.3 and keeps kernel exception checks enabled. Full OCCT sources and binaries are not bundled in this package.
Working on OCEx
This is a standalone repository. See development for local checks and releasing for this package's release steps.