Load and Plot from a File

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Load and Plot from a File#

Read a dataset from a known file type.

We try to make loading a mesh as easy as possible - if your data is in one of the many supported file formats, simply use pyvista.read() to load your spatially referenced dataset into a PyVista mesh object.

The following code block uses a built-in example file and displays an airplane mesh.

import pyvista as pv
from pyvista import examples
help(pv.read)
Help on function read in module pyvista.core.utilities.fileio:

read(filename, force_ext=None, file_format=None, progress_bar=False)
    Read any file type supported by ``vtk`` or ``meshio``.

    Automatically determines the correct reader to use then wraps the
    corresponding mesh as a pyvista object.  Attempts native ``vtk``
    readers first then tries to use ``meshio``.

    See :func:`pyvista.get_reader` for list of formats supported.

    .. note::
       See https://github.com/nschloe/meshio for formats supported by
       ``meshio``. Be sure to install ``meshio`` with ``pip install
       meshio`` if you wish to use it.

    Parameters
    ----------
    filename : str, Path
        The string path to the file to read. If a list of files is
        given, a :class:`pyvista.MultiBlock` dataset is returned with
        each file being a separate block in the dataset.

    force_ext : str, optional
        If specified, the reader will be chosen by an extension which
        is different to its actual extension. For example, ``'.vts'``,
        ``'.vtu'``.

    file_format : str, optional
        Format of file to read with meshio.

    progress_bar : bool, default: False
        Optionally show a progress bar. Ignored when using ``meshio``.

    Returns
    -------
    pyvista.DataSet
        Wrapped PyVista dataset.

    Examples
    --------
    Load an example mesh.

    >>> import pyvista as pv
    >>> from pyvista import examples
    >>> mesh = pv.read(examples.antfile)
    >>> mesh.plot(cpos='xz')

    Load a vtk file.

    >>> mesh = pv.read('my_mesh.vtk')  # doctest:+SKIP

    Load a meshio file.

    >>> mesh = pv.read("mesh.obj")  # doctest:+SKIP

PyVista supports a wide variety of file formats. The supported file extensions are listed in an internal function:

Help on function get_reader in module pyvista.core.utilities.reader:

get_reader(filename, force_ext=None)
    Get a reader for fine-grained control of reading data files.

    Supported file types and Readers:

    +----------------+---------------------------------------------+
    | File Extension | Class                                       |
    +================+=============================================+
    | ``.bmp``       | :class:`pyvista.BMPReader`                  |
    +----------------+---------------------------------------------+
    | ``.cas``       | :class:`pyvista.FluentReader`               |
    +----------------+---------------------------------------------+
    | ``.case``      | :class:`pyvista.EnSightReader`              |
    +----------------+---------------------------------------------+
    | ``.cgns``      | :class:`pyvista.CGNSReader`                 |
    +----------------+---------------------------------------------+
    | ``.cube``      | :class:`pyvista.GaussianCubeReader`         |
    +----------------+---------------------------------------------+
    | ``.dat``       | :class:`pyvista.TecplotReader`              |
    +----------------+---------------------------------------------+
    | ``.dcm``       | :class:`pyvista.DICOMReader`                |
    +----------------+---------------------------------------------+
    | ``.dem``       | :class:`pyvista.DEMReader`                  |
    +----------------+---------------------------------------------+
    | ``.facet``     | :class:`pyvista.FacetReader`                |
    +----------------+---------------------------------------------+
    | ``.foam``      | :class:`pyvista.POpenFOAMReader`            |
    +----------------+---------------------------------------------+
    | ``.g``         | :class:`pyvista.BYUReader`                  |
    +----------------+---------------------------------------------+
    | ``.gif``       | :class:`pyvista.GIFReader`                  |
    +----------------+---------------------------------------------+
    | ``.glb``       | :class:`pyvista.GLTFReader`                 |
    +----------------+---------------------------------------------+
    | ``.gltf``      | :class:`pyvista.GLTFReader`                 |
    +----------------+---------------------------------------------+
    | ``.hdf``       | :class:`pyvista.HDFReader`                  |
    +----------------+---------------------------------------------+
    | ``.img``       | :class:`pyvista.DICOMReader`                |
    +----------------+---------------------------------------------+
    | ``.inp``       | :class:`pyvista.AVSucdReader`               |
    +----------------+---------------------------------------------+
    | ``.jpg``       | :class:`pyvista.JPEGReader`                 |
    +----------------+---------------------------------------------+
    | ``.jpeg``      | :class:`pyvista.JPEGReader`                 |
    +----------------+---------------------------------------------+
    | ``.hdr``       | :class:`pyvista.HDRReader`                  |
    +----------------+---------------------------------------------+
    | ``.mha``       | :class:`pyvista.MetaImageReader`            |
    +----------------+---------------------------------------------+
    | ``.mhd``       | :class:`pyvista.MetaImageReader`            |
    +----------------+---------------------------------------------+
    | ``.nii``       | :class:`pyvista.NIFTIReader`                |
    +----------------+---------------------------------------------+
    | ``.nii.gz``    | :class:`pyvista.NIFTIReader`                |
    +----------------+---------------------------------------------+
    | ``.nhdr``      | :class:`pyvista.NRRDReader`                 |
    +----------------+---------------------------------------------+
    | ``.nrrd``      | :class:`pyvista.NRRDReader`                 |
    +----------------+---------------------------------------------+
    | ``.obj``       | :class:`pyvista.OBJReader`                  |
    +----------------+---------------------------------------------+
    | ``.p3d``       | :class:`pyvista.Plot3DMetaReader`           |
    +----------------+---------------------------------------------+
    | ``.ply``       | :class:`pyvista.PLYReader`                  |
    +----------------+---------------------------------------------+
    | ``.png``       | :class:`pyvista.PNGReader`                  |
    +----------------+---------------------------------------------+
    | ``.pnm``       | :class:`pyvista.PNMReader`                  |
    +----------------+---------------------------------------------+
    | ``.pts``       | :class:`pyvista.PTSReader`                  |
    +----------------+---------------------------------------------+
    | ``.pvd``       | :class:`pyvista.PVDReader`                  |
    +----------------+---------------------------------------------+
    | ``.pvti``      | :class:`pyvista.XMLPImageDataReader`        |
    +----------------+---------------------------------------------+
    | ``.pvtk``      | :class:`pyvista.VTKPDataSetReader`          |
    +----------------+---------------------------------------------+
    | ``.pvtr``      | :class:`pyvista.XMLPRectilinearGridReader`  |
    +----------------+---------------------------------------------+
    | ``.pvtu``      | :class:`pyvista.XMLPUnstructuredGridReader` |
    +----------------+---------------------------------------------+
    | ``.res``       | :class:`pyvista.MFIXReader`                 |
    +----------------+---------------------------------------------+
    | ``.segy``      | :class:`pyvista.SegYReader`                 |
    +----------------+---------------------------------------------+
    | ``.sgy``       | :class:`pyvista.SegYReader`                 |
    +----------------+---------------------------------------------+
    | ``.slc``       | :class:`pyvista.SLCReader`                  |
    +----------------+---------------------------------------------+
    | ``.stl``       | :class:`pyvista.STLReader`                  |
    +----------------+---------------------------------------------+
    | ``.tif``       | :class:`pyvista.TIFFReader`                 |
    +----------------+---------------------------------------------+
    | ``.tiff``      | :class:`pyvista.TIFFReader`                 |
    +----------------+---------------------------------------------+
    | ``.tri``       | :class:`pyvista.BinaryMarchingCubesReader`  |
    +----------------+---------------------------------------------+
    | ``.vrt``       | :class:`pyvista.ProStarReader`              |
    +----------------+---------------------------------------------+
    | ``.vti``       | :class:`pyvista.XMLImageDataReader`         |
    +----------------+---------------------------------------------+
    | ``.vtk``       | :class:`pyvista.VTKDataSetReader`           |
    +----------------+---------------------------------------------+
    | ``.vtm``       | :class:`pyvista.XMLMultiBlockDataReader`    |
    +----------------+---------------------------------------------+
    | ``.vtmb``      | :class:`pyvista.XMLMultiBlockDataReader`    |
    +----------------+---------------------------------------------+
    | ``.vtp``       | :class:`pyvista.XMLPolyDataReader`          |
    +----------------+---------------------------------------------+
    | ``.vtr``       | :class:`pyvista.XMLRectilinearGridReader`   |
    +----------------+---------------------------------------------+
    | ``.vts``       | :class:`pyvista.XMLStructuredGridReader`    |
    +----------------+---------------------------------------------+
    | ``.vtu``       | :class:`pyvista.XMLUnstructuredGridReader`  |
    +----------------+---------------------------------------------+
    | ``.xdmf``      | :class:`pyvista.XdmfReader`                 |
    +----------------+---------------------------------------------+
    | ``.vtpd``      | :class:`pyvista.XMLPartitionedDataSetReader`|
    +----------------+---------------------------------------------+

    Parameters
    ----------
    filename : str, Path
        The string path to the file to read.

    force_ext : str, optional
        An extension to force a specific reader to be chosen.

    Returns
    -------
    pyvista.BaseReader
        A subclass of :class:`pyvista.BaseReader` is returned based on file type.

    Examples
    --------
    >>> import pyvista as pv
    >>> from pyvista import examples
    >>> filename = examples.download_human(load=False)
    >>> filename.split("/")[-1]  # omit the path
    'Human.vtp'
    >>> reader = pv.get_reader(filename)
    >>> reader
    XMLPolyDataReader('.../Human.vtp')
    >>> mesh = reader.read()
    >>> mesh
    PolyData ...
    >>> mesh.plot(color='lightblue')

The following code block uses a built-in example file, displays an airplane mesh and returns the camera’s position:

# Get a sample file
filename = examples.planefile
filename
'/home/runner/.virtualenvs/.venv/lib/python3.10/site-packages/pyvista/examples/airplane.ply'

Note the above filename, it’s a .ply file - one of the many supported formats in PyVista.

Use pv.read to load the file as a mesh:

e read file

The points from the mesh are directly accessible as a NumPy array:

pyvista_ndarray([[896.994  ,  48.7601 ,  82.2656 ],
                 [906.593  ,  48.7601 ,  80.7452 ],
                 [907.539  ,  55.4902 ,  83.6581 ],
                 ...,
                 [806.665  , 627.363  ,   5.11482],
                 [806.665  , 654.432  ,   7.51998],
                 [806.665  , 681.537  ,   9.48744]], dtype=float32)

The faces from the mesh are also directly accessible as a NumPy array:

mesh.faces.reshape(-1, 4)[:, 1:]  # triangular faces
array([[   0,    1,    2],
       [   0,    2,    3],
       [   4,    5,    1],
       ...,
       [1324, 1333, 1323],
       [1325, 1216, 1334],
       [1325, 1334, 1324]])

Loading other files types is just as easy! Simply pass your file path to the pyvista.read() function and that’s it!

Here are a few other examples - simply replace examples.download_* in the examples below with pyvista.read('path/to/you/file.ext')

Example STL file:

mesh = examples.download_cad_model()
cpos = [(107.0, 68.5, 204.0), (128.0, 86.5, 223.5), (0.45, 0.36, -0.8)]
mesh.plot(cpos=cpos)
e read file

Example OBJ file

mesh = examples.download_doorman()
mesh.plot(cpos="xy")
e read file

Example BYU file

mesh = examples.download_teapot()
mesh.plot(cpos=[-1, 2, -5], show_edges=True)
e read file

Example VTK file

mesh = examples.download_bunny_coarse()
cpos = [(0.2, 0.3, 0.9), (0, 0, 0), (0, 1, 0)]
mesh.plot(cpos=cpos, show_edges=True, color=True)
e read file

Exercise#

Read a file yourself with pyvista.read(). If you have a supported file format, use that! Otherwise, download this file: pyvista/pyvista-tutorial

# (your code here)
# mesh = pv.read('path/to/file.vtk)
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