doc: Add extended migration guide

Author: AlejandroFernandezLuces

doc/source/index.rst

@@ -68,6 +68,7 @@ The Visualization Interface Tool offers these main features:
 
        getting_started/index
        user_guide/index
+       user_guide/migration
        {% if build_api %}
        api/index
        {% endif %}

doc/source/user_guide/index.rst

@@ -6,7 +6,8 @@ User guide
 
 This section explains key concepts for implementing the Visualization Interface Tool in your workflow.
 You can use the Visualization Interface Tool in your examples as well as integrate this library into
-your own code.
+your own code. If you need further details on how to migrate from PyVista, please refer to the
+:ref:`ref_migration_guide` section.
 
 Default plotter usage
 =====================
@@ -108,3 +109,5 @@ class. After that, see these main use cases for customizing the plotter:
 
 Some practical examples of how to use the ``PlotterInterface`` class are included in some PyAnsys libraries,
 such as `PyAnsys Geometry <https://github.com/ansys/pyansys-geometry/pull/959>`_.
+
+An extended migration guide with code examples is available in :ref:`ref_migration_guide`.

doc/source/user_guide/migration.rst

@@ -0,0 +1,219 @@
+.. _ref_migration_guide:
+
+Migration
+#########
+
+In this section we will provide guides to help you migrate from PyVista plotters to the Ansys Tools Visualization Interface plotters.
+The first one will address code migration, and the second one will address documentation migration.
+
+Code migration guide
+====================
+
+This guide intends to help users transition from PyVista plotters to the new Ansys Tools Visualization Interface plotters. Since cases are very different
+from each other, a few examples are provided to cover the most common scenarios.
+
+From simple PyVista mesh plotting to the Ansys visualization interface plotter
+------------------------------------------------------------------------------
+If you only need to plot simple PyVista meshes, you can directly replace your PyVista plotter code with the Ansys Tools Visualization Interface plotter code.
+On top of common PyVista functionalities, the Ansys Tools Visualization Interface plotter provides additional interactivity such as view buttons, mesh slicing, etc.
+Here is an example of how to do this:
+
+- PyVista code:
+
+.. code-block:: python
+    
+    import pyvista as pv
+
+    # Create a pyvista mesh
+    mesh = pv.Cube()
+
+    # Create a plotter
+    pl = pv.Plotter()
+
+    # Add the mesh to the plotter
+    pl.add_mesh(mesh)
+
+    # Show the plotter
+    pl.show()
+
+- Ansys Tools Visualization Interface code:
+
+.. code-block:: python
+
+    import pyvista as pv
+    from ansys.tools.visualization_interface import Plotter
+
+    # Create a pyvista mesh
+    mesh = pv.Cube()
+
+    # Create a plotter
+    pl = Plotter()
+
+    # Add the mesh to the plotter
+    pl.plot(mesh)
+
+    # Show the plotter
+    pl.show()
+
+
+Convert your custom meshes to MeshObjectPlot and use the Ansys visualization interface plotter
+----------------------------------------------------------------------------------------------
+
+Your custom object must have a method that returns a PyVista mesh and a method that exposes a ``name`` or ``id`` attribute of your object.
+
+.. code-block:: python
+
+    class CustomObject:
+        def __init__(self):
+            self.name = "CustomObject"
+            self.mesh = pv.Cube(center=(1, 1, 0))
+
+        def get_mesh(self):
+            return self.mesh
+
+        def name(self):
+            return self.name
+
+
+Then you need to create a ``MeshObjectPlot`` instance that relates the PyVista mesh with your custom object.
+
+.. code-block:: python
+
+    from ansys.tools.visualization_interface import MeshObjectPlot
+
+    custom_object = CustomObject()
+    mesh_object_plot = MeshObjectPlot(
+        custom_object=custom_object,
+        mesh=custom_object.get_mesh(),
+    )
+
+With this, you can use the Ansys Tools Visualization Interface plotter to visualize your custom object. It will enable interactivity such as picking and hovering.
+
+
+Customizing the PyVista backend
+-------------------------------
+
+You can customize the backend of the Ansys Tools Visualization Interface plotter to enable or disable certain functionalities. For example, 
+if you want to enable picking, you can do it as follows:
+
+.. code-block:: python
+
+    from ansys.tools.visualization_interface import Plotter
+    from ansys.tools.visualization_interface.backends import PyVistaBackend
+
+    backend = PyVistaBackend(allow_picking=True)
+
+    # Create a plotter
+    pl = Plotter(backend=backend)
+
+    # Add the MeshObjectPlot instance to the plotter
+    pl.plot(mesh_object_plot)
+
+    # Show the plotter
+    pl.show()
+
+If you want to go further and customize the backend even more, you can create your own backend by inheriting from the ``PyVistaBackendInterface`` class 
+and implementing the required methods. You can find more information about this in the backend documentation:
+
+.. code-block:: python
+
+    @abstractmethod
+    def plot_iter(self, plottable_object: Any, name_filter: str = None, **plotting_options):
+        """Plot one or more compatible objects to the plotter.
+
+        Parameters
+        ----------
+        plottable_object : Any
+            One or more objects to add.
+        name_filter : str, default: None.
+            Regular expression with the desired name or names  to include in the plotter.
+        **plotting_options : dict, default: None
+            Keyword arguments. For allowable keyword arguments, see the
+            :meth:`Plotter.add_mesh <pyvista.Plotter.add_mesh>` method.
+
+        """
+        pass
+
+    @abstractmethod
+    def plot(self, plottable_object: Any, name_filter: str = None, **plotting_options):
+        """Plot a single object to the plotter.
+
+        Parameters
+        ----------
+        plottable_object : Any
+            Object to add.
+        name_filter : str
+            Regular expression with the desired name or names to include in the plotter.
+        **plotting_options : dict, default: None
+            Keyword arguments. For allowable keyword arguments, see the
+            :meth:`Plotter.add_mesh <pyvista.Plotter.add_mesh>` method.
+
+        """
+        pass
+
+
+The rest of the methods are implemented for you. This ensures that while you can customize what you need for plotting, the rest of the functionalities will work as expected.
+If you need to even go further, you can also create your own plotter by inheriting from the ``BaseBackend`` class and implementing the required methods,
+although this may break existing functionality. You can find more information about this in the plotter documentation.
+
+Customize the picker or hover behavior
+--------------------------------------
+You can customize the picker of the Ansys Tools Visualization Interface plotter to decide what happens when an object is picked or hovered. 
+For example, if you want to print the name of the picked object, you can do it as described in the custom picker example.
+
+Using PyVista Qt backend
+------------------------
+You can use the PyVista Qt backend with the Ansys Tools Visualization Interface plotter. To do this, you need to set the PyVista backend to Qt 
+before creating the plotter. Here is an example of how to do this:
+
+.. code-block:: python
+
+   cube = pv.Cube()
+   pv_backend = PyVistaBackend(use_qt=True, show_qt=True)
+   pl = Plotter(backend=pv_backend)
+   pl.plot(cube)
+   pl.backend.enable_widgets()
+   pv_backend.scene.show()
+
+With this, you can integrate the plotter into a PyQt or PySide application by disabling ``show_qt`` parameter. 
+You can find more information about this in the `PyVista documentation <https://qtdocs.pyvista.org/>`_.
+
+
+Documentation migration guide
+=============================
+
+This guide is intended to help users transition from PyVista documentation configuration to the new Ansys Tools Visualization Interface documentation configuration.
+
+1. Add environment variables for documentation:
+
+.. code-block:: python
+
+    os.environ["PYANSYS_VISUALIZER_DOC_MODE"] = "true"
+    os.environ["PYANSYS_VISUALIZER_HTML_BACKEND"] = "true"
+
+2. Use PyVista DynamicScraper:
+
+.. code-block:: python
+
+    from pyvista.plotting.utilities.sphinx_gallery import DynamicScraper
+    sphinx_gallery_conf = {
+        ...
+        "image_scrapers": (DynamicScraper()),
+        ...
+    }
+
+3. Add PyVista viewer directive to extensions:
+
+.. code-block:: python
+
+    extensions = [
+        ...
+        "pyvista.ext.viewer_directive",
+        ...
+    ]
+
+4. Make sure you are executing the notebook cells:
+
+.. code-block:: python
+
+    nbsphinx_execute = "always"