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

.. only:: html

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

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

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

.. _sphx_glr__gallery_validation_validate_blend_bg.py:


Validate transparency with and without bg
=========================================

Shows a semi-transparent square. On the left it uses a background, on
the right it does not.

In the latter case, there is no background to blend with, so the
resulting pixels are still semi-transparent. When these final pixels
are shown on screen, they are blended with a virtual black background
(i.e. the alpha channel is applied), resulting in a darker appearance.

The semi-transparent regions may also be blended with your desktop, if
the OS and GUI library are configured to do so.

.. GENERATED FROM PYTHON SOURCE LINES 16-48



.. image-sg:: /_gallery/validation/images/sphx_glr_validate_blend_bg_001.webp
   :alt: validate blend bg
   :srcset: /_gallery/validation/images/sphx_glr_validate_blend_bg_001.webp
   :class: sphx-glr-single-img





.. code-block:: Python



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


    canvas = RenderCanvas(size=(600, 600))
    renderer = gfx.renderers.WgpuRenderer(canvas)

    geometry = gfx.plane_geometry(100, 100)

    plane_bg = gfx.Mesh(
        geometry, gfx.MeshBasicMaterial(color=(0, 0, 0, 1), alpha_mode="blend")
    )
    plane_red = gfx.Mesh(
        geometry, gfx.MeshBasicMaterial(color=(0, 1, 0, 0.3), alpha_mode="blend")
    )

    plane_bg.local.position = -50, 0, 0
    plane_red.local.position = 0, 0, 10

    scene = gfx.Scene()
    scene.add(plane_bg, plane_red)

    camera = gfx.OrthographicCamera(100, 100)

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


    if __name__ == "__main__":
        print(__doc__)
        loop.run()


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

   **Total running time of the script:** (0 minutes 0.196 seconds)


.. _sphx_glr_download__gallery_validation_validate_blend_bg.py:

.. only:: html

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

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

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

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

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

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

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