**********************************
ParaView And Others External Tools
**********************************

Muscat offers some capabilities to communicate with external mesh dedicated tools.

Vtk [#vtk]_
###########

If you have a working VTK installation, you can set the module :py:mod:`Muscat.Bridges.vtkBridge` to convert meshes back and forth to Muscat meshes.
::

    from Muscat.Bridges.vtkBridge import MeshToVtk, VtkToMesh
    BTMesh =  #<-- this is my Muscat Mesh
    vtkMesh = MeshToVtk(BTMesh, tagsAsFields=True)
    # do some work with VTK
    vtk MeshII = #<- create a new vtk mesh from the output of a filter
    BTMeshII = VtkToMesh(vtkMeshII,FieldsAsTags=True)

ParaView [#paraview]_
#####################

Conda/Mamba Users Installation
******************************

For the moment this functionality is not available on conda environment installation even if the plugin is installed in the path ``/conda_env_path/ParaViewPlugins/MuscatParaViewBridge.py``
The reason is the incompatibility of the ParaView python with the conda python.
We are working on a solution for this problem

Developer Installation
**********************

Some functionalities (like readers, writers) can be added to ParaView as a plugin.
The configuration consists in setting the ``PYTHONPATH`` environment variable to your Muscat installation

    ``PYTHONPATH=/path/to/Muscat/src``

Then you can load the plugin ``/path/to/Muscat/extras/MuscatParaViewBridge.py`` using the **Tools->Manage Plugins...** menu.
Also, you can set the ``PV_PLUGIN_PATH`` environment variable to indicate to ParaView to load automatically the plugin when starting.

    ``PV_PLUGIN_PATH=/path/to/Muscat/extras``

Three types of object are added to ParaView by the plugin:

* Readers: The Muscat capabilities to read data from different file formats.
* Writers: The Muscat capabilities to export data to different file formats.
* Filters: Some of the mesh treatment functionalities of Muscat are exposed as vtk filters.

Be aware that the use of this functionalities involves a format conversion between the vtk and the Muscat internal format.
Be aware that your Python installation version may not be compatible with Python version of ParaView.


MeshIO [#meshio]_
###################
MeshIO is a library capable of reading and writing to various mesh file formats.

If you have a working MeshIO installation, you can set the module :py:mod:`Muscat.Bridges.MeshIOBridge` to convert meshes back and forth to Muscat meshes.
MeshIO offers some reading and writing capabilities.
More informations in :py:mod:`Muscat.Bridges.MeshIOBridge`.

PyVista [#pyvista]_
###################
If you have a working PyVista installation, you can set the module :py:mod:`Muscat.Bridges.PyVistaBridge` to convert meshes back and forth to Muscat meshes.

PyVista offers a very simple interface for the visualisation of 3D meshes.
More informations in Muscat.Bridges.PyVistaBridge

MMG [#mmg]_
###########
MMG is a remeshing tools that simplify adaptation and optimization of the meshes. An interface is available in Musccat to use the :py:mod:``Muscat.MeshContainers.Mesh`` class directly.
This can be done using:

.. code-block:: python

    # 2D mesh example
    import numpy as np
    from Muscat.MeshTools.MeshCreationTools import CreateMeshOfTriangles, CreateCube
    from Muscat.MeshTools.Remesh import Remesh
    from Muscat.Simple import PlotMesh

    nodes = np.array([[0.0,0.0],[1.0,0.0],[1.0,1.0],[0.0,1.0]])
    tris = np.array([[0,1,3],[1,2,3]])
    mesh2D = CreateMeshOfTriangles(nodes, tris)
    PlotMesh(mesh2D)

    new2Dmesh = Remesh(mesh2D, remesher_options={"hmin":0.05, "hmax":0.5}) # can take float value
    PlotMesh(new2Dmesh)

    new2Dmesh = Remesh(mesh2D, metric=np.full(mesh2D.GetNumberOfNodes(), 0.05)) # cat take a scalar metric field
    PlotMesh(new2Dmesh)

    # 3D mesh example
    mesh3D = CreateCube([2,2,2], [0,0,0], [1,1,1], True) # Create cube in [0,0,0] with [2,2,2] points with spacing [1,1,1]
    new3Dmesh = Remesh(mesh3D, remesher_options={"hmin":0.05, "hmax":0.5}) # cat take a scalar metric field
    PlotMesh(new3Dmesh)


.. rubric:: Footnotes
.. [#vtk] https://vtk.org/
.. [#paraview] https://www.paraview.org/
.. [#meshio] https://github.com/nschloe/meshio
.. [#pyvista] https://www.pyvista.org/
.. [#mmg] http://www.mmgtools.org/