Meshers Python 0.1.0

In-process CPU float64 meshing of bounded implicit solids. No subprocess or intermediate mesh file is needed.

Install and use

Use Python 3.10+. Wheels are available for Linux x86-64, Windows x86-64, macOS Apple Silicon and macOS Intel. Users installing a wheel do not need Rust, Numba or SymPy.

python -m pip install "meshers[io]"

The base installation, pip install meshers, requires NumPy. The optional io extra adds h5py for VTKHDF export; it does not install a viewer.

import meshers

mesh = meshers.generate("gyroid", cells=24, band=(-0.5, 0.5), periodic=(True, True, True))
points, tetrahedra = mesh.points, mesh.tetrahedra
mesh.write_vtkhdf("gyroid.vtkhdf")  # requires h5py

Native fields: gyroid, schwarz_p, schwarz_d; their period is one physical coordinate unit. Bounds default to the unit cube and use (xmin, xmax, ymin, ymax, zmin, zmax). cells accepts an integer or three integers. Without band, the solid is field <= 0. Periodicity defaults to disabled.

Custom and graded functions

Pass a pointwise NumPy-style callable field(x, y, z). Supported expressions compile automatically inside the wheel, with automatic gradients and cached machine code. CPU workers evaluate float64 directly, with the GIL released. This supports callable grading, thickness and blends without an explicit compilation step. See supported operations and limits.

Unsupported expressions fall back to batched NumPy callbacks with a warning. Select that path explicitly with compile=False; callbacks must return (N,) float64 arrays, and optional gradients (N,3). Functions must be deterministic and independent of batch contents. Callback evaluation runs on the calling Python thread.

See the graded example.

Results and failures

• Owned NumPy arrays: float64 points, int64 tetrahedra and boundary triangles.
• Boundary tags: 0 implicit, 1/2 x-/x+, 3/4 y-/y+, 5/6 z-/z+.
• Per-axis periodic node pairs plus geometry and quality diagnostics.
• VTKHDF volume or surface=True, periodic master IDs and physical shift vectors. Volume files include Volume and MMGQuality, computed using the MMG formula in NumPy, not by calling mmgpy.
• Invalid options raise ValueError; failed meshing raises MeshingError. Callback exceptions are preserved. KeyboardInterrupt is propagated.
• Pass cancel=CancellationToken() and call token.cancel() from another thread for cooperative cancellation. A callback must return before it can be interrupted by that token. Tokens remain cancelled after use.

Output arrays own their storage and are mutable. Mutating them can invalidate connectivity, metadata or diagnostics. Surface output is the closed solid boundary, not an independent zero-level surface mesher. Small features may be missed at insufficient resolution; successful sampling is not geometry certification.

Validation and limits

The test suite covers automatic derivatives, cache invalidation, cancellation, periodicity, bounded callbacks, named intersections, physical coordinate scales and VTKHDF round trips. CI tests Python 3.10, 3.12 and 3.14 on Linux, Windows and macOS, plus installed platform wheels and an isolated source build. See the release checks and CI results. Thin, nonsmooth or poorly resolved geometry still needs application-specific convergence checks.

See the runnable examples and performance regression checks.

Maintainer build

Maintainers need a compatible Rust toolchain and Python to build wheels:

python -m pip install maturin
maturin build --release --interpreter python --out dist

End users install the resulting wheels. Source installations require Rust.

Retained intersections and mapped periodic ends

meshers.generate_intersection accepts named negative sublevel constraints, an optional coordinate map and explicit rigid periodic transforms. It returns the same Mesh type, with named surface access, feature edges and parameter coordinates. See the intersection guide and examples/curved_tpms.py. Source builds require Rust 1.95 or newer.