.. _ref_index_surfer:



***************
Surface meshing
***************

The :class:`Surfer <ansys.meshing.prime.Surfer>` class enables you to perform surface meshing using
different surface meshing algorithms on *TopoFaces* or face zonelets. Surface meshing considers many
parameters, such as size field type, minimum size, maximum size, growth rate, and transition type,
while meshing *TopoFaces* or face zonelets.

.. tip::
    Surface meshing with constant and variable sizing with tri/quad mesh can be generated using
    the :func:`Mesh.surface_mesh() <ansys.meshing.prime.lucid.Mesh.surface_mesh>` method in the Lucid API.

=================================
Surface meshing geometry/topology
=================================

The following example shows how to perform these steps:

* Import topology-based geometry (SCDOC) files and visualize the model.
* Surface mesh the TopoFaces with constant size.

Start the PyPrimeMesh client and import the CAD geometry (SCDOC) file:

.. code-block:: python

    import ansys.meshing.prime as prime
    from ansys.meshing.prime.graphics import Graphics

    prime_client = prime.launch_prime()
    model = prime_client.model

    # Import CAD file
    input_file = r"D:/Examples/simple-bracket-holes.scdoc"
    file_io = prime.FileIO(model)
    file_io.import_cad(
        input_file,
        params=prime.ImportCadParams(model=model, length_unit=prime.LengthUnit.MM),
    )
    # Show model in graphic
    display = Graphics(model)
    display(update=True)
    part = model.get_part_by_name("simple-bracket-holes")


.. figure:: ../images/simple-bracket-holes_scdoc.png
    :width: 300pt
    :align: center

    **CAD geometry imported**

Initialize surfer parameters and generate surface mesh on TopoFaces:

.. code-block:: python

    # Surface mesh with triangular elements of uniform size
    surfer_params = prime.SurferParams(model=model, constant_size=1.0)
    surfer_result = prime.Surfer(model).mesh_topo_faces(
        part.id, topo_faces=part.get_topo_faces(), params=surfer_params
    )


.. figure:: ../images/simple-bracket-holes_mesh3.png
    :width: 300pt
    :align: center

    **Surface mesh displayed**

===============
Remesh surfaces
===============

This example shows you to perform these steps:

* Import a faceted geometry (STL) file and visualize the model.
* Create curvature size control and compute a volumetric size field. (For more information,
  see :ref:`ref_index_sizing`.)
* Remesh the STL surface mesh.

Start the PyPrimeMesh client and import the faceted geometry (STL) file:

.. code-block:: python

    import ansys.meshing.prime as prime
    from ansys.meshing.prime.graphics import Graphics

    prime_client = prime.launch_prime()
    model = prime_client.model

    # Import CAD file
    input_file = r"D:/Examples/simple-bracket-holes.stl"
    file_io = prime.FileIO(model)
    file_io.import_cad(
        input_file,
        params=prime.ImportCadParams(model=model, length_unit=prime.LengthUnit.MM),
    )


Now that the CAD file is imported, display the model using graphics module:

.. code-block:: python

    # Show model in graphic and get part summary
    display = Graphics(model)
    display(update=True)
    part = model.get_part_by_name("simple-bracket-holes")
    part_summary_res = part.get_summary(prime.PartSummaryParams(model=model))


.. figure:: ../images/simple-bracket-holes_stl.png
    :width: 300pt
    :align: center

    **Faceted geometry imported**

Print the results of part summary:

.. code-block:: pycon

    >>> print(part_summary_res)

    Part Name: simple-bracket-holes
    Part ID: 2
        0 Edge Zonelets
        1 Face Zonelets
        0 Cell Zonelets

        0 Edge Zones
            Edge Zone Name(s) : []
        0 Face Zones
            Face Zone Name(s) : []
        0 Volume Zones
            Volume Zone Name(s) : []

        0 Label(s)
            Names: []

        Bounding box (-10 -10 -8.17)
                     (19.1 23.075 25.52)

        Mesh Summary:
            1048 Nodes
            0 Poly Faces
            0 Quad Faces
            2124 Tri Faces
            2124 Faces
            0 Cells


Set the global sizing parameters to initialize size control parameters (with curvature refinement):

.. code-block:: python

    # Surface mesh size controls
    model.set_global_sizing_params(
        prime.GlobalSizingParams(model, min=0.27, max=5.5, growth_rate=1.2)
    )
    size_control = model.control_data.create_size_control(prime.SizingType.CURVATURE)
    size_control.set_scope(prime.ScopeDefinition(model))


Compute the volumetric size field based on the size controls:

.. code-block:: python

    size_field = prime.SizeField(model)
    res = size_field.compute_volumetric(
        size_control_ids=[size_control.id],
        volumetric_sizefield_params=prime.VolumetricSizeFieldComputeParams(
            model, enable_multi_threading=False
        ),
    )


Initialize surfer parameters and generate a surface mesh on face zonelets:

.. code-block:: python

    # Surface mesh with triangular elements
    surfer_params = prime.SurferParams(
        model=model, size_field_type=prime.SizeFieldType.VOLUMETRIC
    )
    surfer_result = prime.Surfer(model).remesh_face_zonelets(
        part_id=part.id,
        face_zonelets=part.get_face_zonelets(),
        edge_zonelets=part.get_edge_zonelets(),
        params=surfer_params,
    )


.. figure:: ../images/simple-bracket-holes_mesh1.png
    :width: 300pt
    :align: center

    **Surface mesh displayed**