pyramids-mesh

pyramids-mesh reads and writes the file formats of hydrodynamic and hydraulic mesh models — 2DM, Selafin, DFSU, XMDF, PLY and more — as pyramids UGRID objects. pyramids-gis already ships the mesh data model and every operation that follows from a topology in hand; what it cannot do is open other people's mesh files. That is this package's job, and its only job.

What pyramids-gis owns today, and this package therefore does not reimplement:

• The data model — Mesh2d, Network1d, UgridDataset, Connectivity, and UGRID-compliant NetCDF read/write.
• Topology operations on a mesh already in hand — connectivity derivation, graph algorithms (components, RCM ordering, dilation/erosion, Voronoi, circumcenters, boundary extraction), facet remapping, spatial indexing.
• Regridding and sampling — point sampling, rasterize_like, mesh-to-mesh conservative / barycentric / centroid regridding, temporal interpolation.
• Conversion — mesh ↔ vector, construction from a raster grid or a polygon layer, xarray/zarr hand-off, gap filling.

What this package adds — file-format drivers, and nothing else:

• Readers for the native formats of hydrodynamic and hydraulic solvers: 2DM (SMS / TUFLOW / BASEMENT), Selafin (TELEMAC), DFSU and DFS2 (DHI MIKE), XMDF and XDMF, DAT, FLO-2D, 3Di, H2i, Mike21, HEC-RAS 2D, plus the geometry interchange formats PLY and TIN.
• Writers for the formats that support it — 2DM, Selafin, DAT, PLY, Mike21.
• Discovery through the pyramids.mesh_drivers entry-point group, so UgridDataset.read_file("model.slf") just works once this package is installed.

Every mesh operation belongs upstream in pyramids-gis. A driver parses a file and builds pyramids.netcdf.ugrid objects; it implements no GIS, no interpolation and no analysis.

Status — 0.1.0 is the repository scaffold: packaging, CI, docs and the import contract. No mesh API is published yet. Follow the change log for what lands.

Naming note — the distribution name is pyramids-mesh (with hyphen), the Python import name is pyramids_mesh (with underscore).

Installation

The package is not published yet. Install it from source with Pixi:

git clone https://github.com/serapeum-org/pyramids-mesh.git
cd pyramids-mesh
pixi install -e dev      # creates the dev environment
pixi shell -e dev

One extra is declared: viz, which adds the plotting stack (pyramids-gis[viz] + cleopatra) that mesh rendering goes through. The dev environment installs it, so the tests run against the same set an installed user gets.

GDAL is not a dependency. The pyramids-gis wheel vendors its own osgeo bindings, and import pyramids is what puts them on sys.path — which is why import pyramids is the first import in every module here.

Supported Python: 3.11–3.14.

Project layout

src/pyramids_mesh/   — the package (import name: pyramids_mesh)
tests/               — pytest suite
docs/                — MkDocs sources (MkDocs Material + mkdocstrings)
docs/examples/       — example notebooks, validated by `pixi run notebooks`
examples/data/       — data the notebooks read, via notebook-relative paths

Documentation

• Live site: https://serapeum-org.github.io/pyramids-mesh/latest/
• Local preview: pixi run -e docs mkdocs serve

Development

This repository uses Pixi for environment management.

pixi run main          # main test suite (excludes plot tests)
pixi run plot          # plot/visualization tests
pixi run test-all      # everything, with a terminal coverage report
pixi run notebooks     # validate example notebooks
pre-commit run --all-files

Branches and commits follow Conventional Commits: branch <type>/<short-description>, PR title <type>: <imperative summary>. Releases are driven by commitizen (pixi run cz-bump) and the shared serapeum-org/github-actions workflows.

License

GNU General Public License v3 — see LICENSE.