.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "gallery/scene/mesh_normals.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

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

        :ref:`Go to the end <sphx_glr_download_gallery_scene_mesh_normals.py>`
        to download the full example code

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_gallery_scene_mesh_normals.py:


Display Mesh Normals
====================

Show how to display mesh normals on a mesh.

.. GENERATED FROM PYTHON SOURCE LINES 13-59



.. image-sg:: /gallery/scene/images/sphx_glr_mesh_normals_001.png
   :alt: mesh normals
   :srcset: /gallery/scene/images/sphx_glr_mesh_normals_001.png
   :class: sphx-glr-single-img


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

 .. code-block:: none

    Key bindings:
     f : toggle face normals
     v : toggle vertex normals






|

.. code-block:: Python


    from vispy import app, scene
    from vispy.io import read_mesh, load_data_file
    from vispy.scene.visuals import Mesh, MeshNormals
    from vispy.visuals.filters import WireframeFilter


    mesh_file = load_data_file('orig/triceratops.obj.gz')
    vertices, faces, _, _ = read_mesh(mesh_file)

    mesh = Mesh(vertices, faces, shading='flat')
    meshdata = mesh.mesh_data

    wireframe_filter = WireframeFilter(color='lightblue')
    mesh.attach(wireframe_filter)

    face_normals = MeshNormals(meshdata, primitive='face', color='yellow')
    vertex_normals = MeshNormals(meshdata, primitive='vertex', color='orange',
                                 width=2)

    canvas = scene.SceneCanvas(keys='interactive', bgcolor='white')
    view = canvas.central_widget.add_view()
    view.camera = 'arcball'
    view.add(mesh)
    face_normals.parent = mesh
    vertex_normals.parent = mesh


    @canvas.events.key_press.connect
    def on_key_press(event):
        if event.key == 'f':
            face_normals.visible = not face_normals.visible
            canvas.update()
        elif event.key == 'v':
            vertex_normals.visible = not vertex_normals.visible
            canvas.update()


    canvas.show()


    if __name__ == "__main__":
        print('Key bindings:')
        print(' f : toggle face normals')
        print(' v : toggle vertex normals')
        app.run()


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

   **Total running time of the script:** (0 minutes 1.227 seconds)


.. _sphx_glr_download_gallery_scene_mesh_normals.py:

.. only:: html

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

    .. container:: sphx-glr-download sphx-glr-download-jupyter

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

    .. container:: sphx-glr-download sphx-glr-download-python

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


.. only:: html

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

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