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

.. only:: html

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

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

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

.. _sphx_glr__gallery_introductory_offscreen.py:


Offscreen Rendering
===================

Example demonstrating off-screen rendering.

This uses wgpu's offscreen canvas to obtain the frames as a numpy array.
Note that one can also render to a ``pygfx.Texture`` and use that texture to
decorate an object in another scene.

.. GENERATED FROM PYTHON SOURCE LINES 11-63



.. image-sg:: /_gallery/introductory/images/sphx_glr_offscreen_001.webp
   :alt: offscreen
   :srcset: /_gallery/introductory/images/sphx_glr_offscreen_001.webp
   :class: sphx-glr-single-img


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

 .. code-block:: none

    Imageio: 'astronaut.png' was not found on your computer; downloading it now.
    Try 1. Download from https://github.com/imageio/imageio-binaries/raw/master/images/astronaut.png (773 kB)
    Downloading: 8192/791555 bytes (1.0%)791555/791555 bytes (100.0%)
      Done
    File saved as /home/docs/.imageio/images/astronaut.png.
    image from canvas.draw(): (480, 640, 4)
    Image from renderer.snapshot(): (960, 1280, 4)






|

.. code-block:: Python



    import os
    import tempfile
    import webbrowser

    import imageio.v3 as iio
    import numpy as np
    import pygfx as gfx
    import pylinalg as la
    from rendercanvas.offscreen import RenderCanvas


    # Create offscreen canvas, renderer and scene
    canvas = RenderCanvas(size=(640, 480), pixel_ratio=1)
    renderer = gfx.renderers.WgpuRenderer(canvas)
    scene = gfx.Scene()
    scene.add(gfx.Background.from_color("#000"))

    im = iio.imread("imageio:astronaut.png").astype("float32") / 255
    tex = gfx.Texture(im, dim=2)

    geometry = gfx.box_geometry(200, 200, 200)
    material = gfx.MeshBasicMaterial(map=tex)
    cube = gfx.Mesh(geometry, material)
    scene.add(cube)

    camera = gfx.PerspectiveCamera(70, 16 / 9)
    camera.local.z = 400

    rot = la.quat_from_euler((0.5, 1.0), order="XY")
    cube.local.rotation = la.quat_mul(rot, cube.local.rotation)

    canvas.request_draw(lambda: renderer.render(scene, camera))


    if __name__ == "__main__":
        # The offscreen canvas has a draw method that returns a memoryview.
        # Use this to obtain what you normally see on-screen. You should
        # only use an offscreen canvas for e.g. testing or generating images.
        im1 = np.asarray(canvas.draw())
        print("image from canvas.draw():", im1.shape)  # (480, 640, 4)

        # The renderer also has a snapshot utility. With this you get a snapshot
        # of the internal state (might be at a higher resolution).
        # The use of the snapshot method may change and be improved.
        im2 = renderer.snapshot()
        print("Image from renderer.snapshot():", im2.shape)  # (960, 1280, 4)

        filename = os.path.join(tempfile.gettempdir(), "pygfx_offscreen.png")
        iio.imwrite(filename, im2)
        webbrowser.open("file://" + filename)


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

   **Total running time of the script:** (0 minutes 0.942 seconds)


.. _sphx_glr_download__gallery_introductory_offscreen.py:

.. only:: html

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

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

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

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

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

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

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