.. note::
    :class: sphx-glr-download-link-note

    Click :ref:`here <sphx_glr_download_auto_tutorials_01_introductory_viz_surfaces.py>` to download the full example code
.. rst-class:: sphx-glr-example-title

.. _sphx_glr_auto_tutorials_01_introductory_viz_surfaces.py:


==================
Visualize surfaces
==================

Here is a simple tutorial that shows how to visualize surfaces using DIPY. It
also shows how to load/save, get/set and update ``vtkPolyData`` and show
surfaces.

``vtkPolyData`` is a structure used by VTK to represent surfaces and other data
structures. Here we show how to visualize a simple cube but the same idea
should apply for any surface.


.. code-block:: default


    import numpy as np







Import useful functions


.. code-block:: default


    from fury import window, utils
    from fury.io import save_polydata, load_polydata
    from fury.utils import vtk







Create an empty ``vtkPolyData``


.. code-block:: default


    my_polydata = vtk.vtkPolyData()







Create a cube with vertices and triangles as numpy arrays


.. code-block:: default


    my_vertices = np.array([[0.0, 0.0, 0.0],
                           [0.0, 0.0, 1.0],
                           [0.0, 1.0, 0.0],
                           [0.0, 1.0, 1.0],
                           [1.0, 0.0, 0.0],
                           [1.0, 0.0, 1.0],
                           [1.0, 1.0, 0.0],
                           [1.0, 1.0, 1.0]])
    # the data type for vtk is needed to mention here, numpy.int64
    my_triangles = np.array([[0, 6, 4],
                             [0, 2, 6],
                             [0, 3, 2],
                             [0, 1, 3],
                             [2, 7, 6],
                             [2, 3, 7],
                             [4, 6, 7],
                             [4, 7, 5],
                             [0, 4, 5],
                             [0, 5, 1],
                             [1, 5, 7],
                             [1, 7, 3]], dtype='i8')








Set vertices and triangles in the ``vtkPolyData``


.. code-block:: default


    utils.set_polydata_vertices(my_polydata, my_vertices)
    utils.set_polydata_triangles(my_polydata, my_triangles)







Save the ``vtkPolyData``


.. code-block:: default


    file_name = "my_cube.vtk"
    save_polydata(my_polydata, file_name)
    print("Surface saved in " + file_name)





.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    Surface saved in my_cube.vtk



Load the ``vtkPolyData``


.. code-block:: default


    cube_polydata = load_polydata(file_name)







add color based on vertices position


.. code-block:: default


    cube_vertices = utils.get_polydata_vertices(cube_polydata)
    colors = cube_vertices * 255
    utils.set_polydata_colors(cube_polydata, colors)

    print("new surface colors")
    print(utils.get_polydata_colors(cube_polydata))





.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    new surface colors
    [[  0   0   0]
     [  0   0 255]
     [  0 255   0]
     [  0 255 255]
     [255   0   0]
     [255   0 255]
     [255 255   0]
     [255 255 255]]



Visualize surfaces


.. code-block:: default


    # get vtkActor
    cube_actor = utils.get_actor_from_polydata(cube_polydata)

    # Create a scene
    scene = window.Scene()
    scene.add(cube_actor)
    scene.set_camera(position=(10, 5, 7), focal_point=(0.5, 0.5, 0.5))
    scene.zoom(3)

    # display
    # window.show(scene, size=(600, 600), reset_camera=False)
    window.record(scene, out_path='cube.png', size=(600, 600))



.. image:: /auto_tutorials/01_introductory/images/sphx_glr_viz_surfaces_001.png
    :class: sphx-glr-single-img





.. rst-class:: sphx-glr-timing

   **Total running time of the script:** ( 0 minutes  0.105 seconds)


.. _sphx_glr_download_auto_tutorials_01_introductory_viz_surfaces.py:


.. only :: html

 .. container:: sphx-glr-footer
    :class: sphx-glr-footer-example



  .. container:: sphx-glr-download

     :download:`Download Python source code: viz_surfaces.py <viz_surfaces.py>`



  .. container:: sphx-glr-download

     :download:`Download Jupyter notebook: viz_surfaces.ipynb <viz_surfaces.ipynb>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_