.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "_gallery/feature_demo/colormap_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_colormap_mesh.py>`
        to download the full example code.

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

.. _sphx_glr__gallery_feature_demo_colormap_mesh.py:


Colormap Mesh
=============

Example demonstrating different colormap dimensions on a mesh, and
per-vertex colors as a bonus.

The default visiualization is a mesh, but by (un)commenting a few lines,
this can also be applied for points and lines.

.. GENERATED FROM PYTHON SOURCE LINES 11-142



.. image-sg:: /_gallery/feature_demo/images/sphx_glr_colormap_mesh_001.webp
   :alt: colormap mesh
   :srcset: /_gallery/feature_demo/images/sphx_glr_colormap_mesh_001.webp
   :class: sphx-glr-single-img





.. code-block:: Python



    import numpy as np
    import imageio.v3 as iio
    from rendercanvas.auto import RenderCanvas, loop
    import pygfx as gfx
    import pylinalg as la


    canvas = RenderCanvas(size=(900, 400))
    renderer = gfx.renderers.WgpuRenderer(canvas)
    scene = gfx.Scene()


    def get_geometry(**kwargs):
        geo = gfx.cylinder_geometry(
            height=2, radial_segments=32, height_segments=4, open_ended=False
        )
        for key, val in kwargs.items():
            setattr(geo, key, val)
        return geo


    def WobjectClass(geometry, material):  # noqa
        return gfx.Mesh(geometry, material)
        # return gfx.Points(geometry, material)
        # return gfx.Line(geometry, material)


    def MaterialClass(**kwargs):  # noqa
        return gfx.MeshPhongMaterial(**kwargs)
        # return gfx.PointsMaterial(size=10, **kwargs)
        # return gfx.LineArrowMaterial(thickness=5, **kwargs)


    geometry = get_geometry()

    camera = gfx.OrthographicCamera(16, 3)


    # === 1D colormap
    #
    # For the 1D texcoords we use the second dimension of the default
    # texcoords, which runs from the top to the bottom of the cylinder. The
    # 1D colormap runs from yellow to cyan.

    texcoords1 = geometry.texcoords.data[:, 1].copy()

    cmap1 = np.array([(1, 1, 0), (0, 1, 1)], np.float32)
    tex1 = gfx.Texture(cmap1, dim=1)

    ob1 = WobjectClass(
        get_geometry(texcoords=gfx.Buffer(texcoords1)),
        MaterialClass(map=tex1),
    )
    scene.add(ob1)
    ob1.local.x = -6


    # === 2D colormap
    #
    # For the 2D texcoords we use the default texcoords. For the 2D colormap
    # we use an image texture.

    texcoords2 = geometry.texcoords.data.copy()

    cmap2 = iio.imread("imageio:chelsea.png").astype(np.float32) / 255
    tex2 = gfx.Texture(cmap2, dim=2)

    ob2 = WobjectClass(
        get_geometry(texcoords=gfx.Buffer(texcoords2)),
        MaterialClass(map=tex2),
    )
    scene.add(ob2)
    ob2.local.x = -2


    # === 3D colormap
    #
    # For the 3D texcoords we use (a scaled version of) the positions. For
    # the colormap we use a volume (a 3D image). In effect, the edge of the
    # mesh gets a color that corresponds to the value of the volume at that
    # position. This can be seen as a specific (maybe somewhat odd) type
    # of volume rendering.

    texcoords3 = geometry.positions.data * 0.4 + 0.5

    cmap3 = iio.imread("imageio:stent.npz").astype(np.float32) / 1000
    tex3 = gfx.Texture(cmap3, dim=3)

    ob3 = WobjectClass(
        get_geometry(texcoords=gfx.Buffer(texcoords3)),
        MaterialClass(map=tex3),
    )
    scene.add(ob3)
    ob3.local.x = +2


    # === Per vertex coloring
    #
    # To specify a color for each vertex, provide a geometry.colors buffer and
    # set the material.color_mode to 'vertex'. We use the normals as input.

    colors = geometry.normals.data * 0.4 + 0.5
    colors = colors[:, :3]  # Colors can be Nx1, Nx2, Nx3, Nx4

    ob4 = WobjectClass(
        get_geometry(colors=gfx.Buffer(colors)),
        MaterialClass(color_mode="vertex"),
    )
    scene.add(ob4)
    ob4.local.x = +6

    scene.add(gfx.AmbientLight())
    light = gfx.DirectionalLight()
    light.local.z = 1
    scene.add(light)


    def animate():
        rot = la.quat_from_euler((0.0071, 0.01), order="XY")
        for obj in scene.children:
            obj.local.rotation = la.quat_mul(rot, obj.local.rotation)

        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 0.643 seconds)


.. _sphx_glr_download__gallery_feature_demo_colormap_mesh.py:

.. only:: html

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

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

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

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

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

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

      :download:`Download zipped: colormap_mesh.zip <colormap_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#colormap_mesh.py"></iframe>