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

.. only:: html

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

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

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

.. _sphx_glr__gallery_feature_demo_quad_mesh.py:


Mesh with quads
===============

This example demonstrates the use of meshes with quad faces.
Quad faces are used when geometry.indices array is Nx4 instead of Nx3.

This example also demonstrates per-vertex and per-face coloring.

Contributed by S. Shaji

.. GENERATED FROM PYTHON SOURCE LINES 12-125



.. image-sg:: /_gallery/feature_demo/images/sphx_glr_quad_mesh_001.webp
   :alt: quad mesh
   :srcset: /_gallery/feature_demo/images/sphx_glr_quad_mesh_001.webp
   :class: sphx-glr-single-img





.. code-block:: Python



    import numpy as np
    from rendercanvas.auto import RenderCanvas, loop
    import pygfx as gfx


    def generate_sample_quads(cols=9):
        pos = np.dstack(np.meshgrid(np.arange(cols), np.arange(2))).reshape(-1, 2)
        z = np.abs([*np.arange(-cols / 2, cols / 2), *np.arange(-cols / 2, cols / 2)])
        pos = np.c_[pos, z].astype("f")
        n1 = np.arange(cols)
        n2 = np.full(cols - 1, 0)
        n3 = np.full(cols - 1, 1)
        idx = np.dstack((n1[:-1], n2, n1[:-1], n3, n1[1:], n3, n1[1:], n2)).reshape(-1, 2)
        indices = (idx[:, 0] + idx[:, 1] * cols).reshape(-1, 4)
        return pos, indices.astype(np.int32)


    canvas = RenderCanvas(
        title="Mesh Object with quads. Press 1,2 or 3 for wireframe, per vertex coloring or per face coloring"
    )
    renderer = gfx.renderers.WgpuRenderer(canvas)

    # Show something
    scene = gfx.Scene()
    camera = gfx.PerspectiveCamera()

    controller = gfx.OrbitController(camera=camera, register_events=renderer)
    controller.controls["mouse3"] = ("pan", "drag", (1.0, 1.0))

    # Generate Sample quads and draw them
    pos, indices = generate_sample_quads()
    colors = np.repeat(pos[:, -1] / pos[:, -1].max(), 4).reshape(-1, 4)
    colors[:, 2] = 1
    colors[:, 3] = 1

    patches = gfx.Mesh(
        gfx.Geometry(
            indices=indices,
            positions=pos,
            colors=colors,
            texcoords=np.linspace(0, 1, len(indices), dtype=np.float32),
        ),
        gfx.MeshBasicMaterial(
            color_mode="uniform",
            wireframe=True,
            wireframe_thickness=3,
            map=gfx.cm.magma,
            pick_write=True,
        ),
    )


    scene.add(patches)
    camera.show_object(patches)

    # Let there be ...
    scene.add(gfx.AmbientLight())
    light = gfx.DirectionalLight()
    light.local.position = (0, 0, 1)

    # Create a contrasting background
    clr = [i / 255 for i in [87, 188, 200, 255]]
    background = gfx.Background.from_color(clr)
    scene.add(background)


    def make_wireframe():
        patches.material.wireframe = True
        patches.material.color_mode = "uniform"


    def make_vertex_color():
        patches.material.wireframe = False
        patches.material.color_mode = "vertex"


    def make_face_color():
        patches.material.wireframe = False
        patches.material.color_mode = "face"


    def make_face_color_map():
        patches.material.wireframe = False
        patches.material.color_mode = "face_map"


    @renderer.add_event_handler("key_down")
    def on_key(e):
        if e.key == "1":
            make_wireframe()
        elif e.key == "2":
            make_vertex_color()
        elif e.key == "3":
            make_face_color()
        elif e.key == "4":
            make_face_color_map()


    @renderer.add_event_handler("click")
    def pick_id(event):
        print(event.pick_info)


    def animate():
        renderer.render(scene, camera)
        canvas.request_draw()


    if __name__ == "__main__":
        canvas.request_draw(animate)
        loop.run()


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

   **Total running time of the script:** (0 minutes 0.322 seconds)


.. _sphx_glr_download__gallery_feature_demo_quad_mesh.py:

.. only:: html

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

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

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

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

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

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: quad_mesh.zip <quad_mesh.zip>`


.. only:: html

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

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

.. only:: html

    Interactive example
    -------------------

    Try this example in your browser using Pyodide. Might not work with all examples and all devices. Check the output and your browser's console for details.

    .. raw:: html

        <iframe src="./../pyodide.html#quad_mesh.py"></iframe>