There are various mesh formats available for representing unstructured meshes. meshio can read and write all of the following and smoothly converts between them:

• Abaqus
• ANSYS msh
• DOLFIN XML
• Exodus
• H5M
• Kratos/MDPA
• Medit
• MED/Salome
• Gmsh (versions 2 and 4)
• OFF
• PERMAS
• STL
• SVG (2D only, output only)
• VTK
• VTU
• XDMF

Simply call

meshio-convert input.msh output.vtu

with any of the supported formats.

In Python, simply call

import meshio

mesh = meshio.read(filename)
# mesh.points, mesh.cells, ...

to read a mesh. To write, do

points = numpy.array([
    [0.0, 0.0, 0.0],
    [0.0, 1.0, 0.0],
    [0.0, 0.0, 1.0],
    ])
cells = {
    "triangle": numpy.array([
        [0, 1, 2]
        ])
    }
meshio.write_points_cells(
    "foo.vtk",
    points,
    cells,
    # Optionally provide extra data on points, cells, etc.
    # point_data=point_data,
    # cell_data=cell_data,
    # field_data=field_data
    )

or explicitly create a mesh object for writing

mesh = meshio.Mesh(points, cells)
meshio.write("foo.vtk", mesh)

For both input and output, you can optionally specify the exact file_format (in case you would like to enforce binary over ASCII VTK, for example).

The XDMF format supports time series with a shared mesh. You can write times series data using meshio with

writer = meshio.XdmfTimeSeriesWriter(filename)
writer.write_points_cells(points, cells)
for t in [0.0, 0.1, 0.21]:
    writer.write_point_data({"phi": data}, t)

and read it with

reader = meshio.XdmfTimeSeriesReader(filename)
points, cells = reader.read_points_cells()
for k in range(reader.num_steps):
    t, point_data, cell_data = reader.read_data(k)

meshio is available from the Python Package Index, so simply type

pip install -U meshio

to install or upgrade.

To run the meshio unit tests, check out this repository and type

pytest

To create a new release

1. bump the __version__ number,

2. tag and upload to PyPi:

   make publish
   

meshio is published under the MIT license.