.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_examples\04_demos\viz_ellipsoids.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

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

        :ref:`Go to the end <sphx_glr_download_auto_examples_04_demos_viz_ellipsoids.py>`
        to download the full example code.

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

.. _sphx_glr_auto_examples_04_demos_viz_ellipsoids.py:


============================
Impostor and Mesh Ellipsoids
============================

This tutorial creates two ellipsoids with the same shape. The left ellipsoid
uses a shader-based impostor; the right one uses a tessellated triangle mesh.
Both represent a 3D ellipsoid, but only the mesh stores its surface as vertices
and faces.

The impostor path warns about its different geometry, tessellation, and picking.
Use ``impostor=False`` when mesh vertices, faces, or face coordinates are needed.

Run this script to open the interactive scene.

.. GENERATED FROM PYTHON SOURCE LINES 16-21

.. code-block:: Python


    import numpy as np

    from fury import actor, window








.. GENERATED FROM PYTHON SOURCE LINES 22-26

Define the shape. ``lengths`` are semi-axis lengths, not diameters: these
ellipsoids have full axis lengths of 3.0, 1.6, and 1.0. The columns of the
orientation matrix define the local axis directions; identity aligns them
with X, Y, and Z.

.. GENERATED FROM PYTHON SOURCE LINES 26-31

.. code-block:: Python


    lengths = (1.5, 0.8, 0.5)
    orientation = np.eye(3)
    centers = np.array([[0.0, 0.0, 0.0]])








.. GENERATED FROM PYTHON SOURCE LINES 32-35

Create the impostor ellipsoid on the left. The shader calculates the surface
analytically instead of generating a dense mesh. ``impostor=True`` is the
default, but we specify it here to make the comparison explicit.

.. GENERATED FROM PYTHON SOURCE LINES 35-50

.. code-block:: Python


    impostor = actor.ellipsoid(
        centers=centers,
        orientation_matrices=orientation,
        lengths=lengths,
        colors=(0.0, 0.7, 1.0),
        impostor=True,
    )
    impostor.local.position = (-2.0, 0.0, 0.0)

    impostor.add_event_handler(
        lambda event: print(f"Pointer moved in impostor to: {event.x}, {event.y}"),
        "pointer_move",
    )





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

 .. code-block:: none

    impostor=True uses analytic billboard ellipsoids instead of a triangle mesh: phi and theta are ignored, and picking returns glyph_index instead of mesh face coordinates. Use impostor=False for mesh behavior.

    <function <lambda> at 0x0000026ABA6A91C0>



.. GENERATED FROM PYTHON SOURCE LINES 51-54

Create the mesh ellipsoid on the right. ``phi`` and ``theta`` control its
tessellation and only affect the mesh branch. Use this branch when you need
surface vertices and faces or mesh-specific appearance controls.

.. GENERATED FROM PYTHON SOURCE LINES 54-70

.. code-block:: Python


    mesh = actor.ellipsoid(
        centers=centers,
        orientation_matrices=orientation,
        lengths=lengths,
        colors=(1.0, 0.5, 0.0),
        impostor=False,
        phi=32,
        theta=32,
    )
    mesh.local.position = (2.0, 0.0, 0.0)
    mesh.add_event_handler(
        lambda event: print(f"Pointer moved in mesh to: {event.x}, {event.y}"),
        "pointer_move",
    )





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

 .. code-block:: none


    <function <lambda> at 0x0000026ABA885B20>



.. GENERATED FROM PYTHON SOURCE LINES 71-75

Count the vertices used by each rendering method. Each impostor draws two
triangles (six generated vertices), but stores only its center and parameters.
The mesh count comes from its actual position buffer and changes with
``phi`` and ``theta``.

.. GENERATED FROM PYTHON SOURCE LINES 75-96

.. code-block:: Python


    impostor_vertices = 6 * impostor.glyph_count
    impostor_centers = impostor.geometry.positions.nitems
    mesh_vertices = mesh.geometry.positions.nitems

    labels = actor.text(
        [
            f"Impostor\n{impostor_vertices} generated vertices\n"
            f"{impostor_centers} stored center",
            f"Mesh\n{mesh_vertices} surface vertices",
        ],
        position=[(-2.0, -1.4, 0.0), (2.0, -1.4, 0.0)],
        colors=(1.0, 1.0, 1.0),
        font_size=0.3,
        anchor="middle-center",
    )

    scene = window.Scene()
    scene.background = (0.05, 0.05, 0.08)
    scene.add(impostor, mesh, labels)








.. GENERATED FROM PYTHON SOURCE LINES 97-98

Open the interactive window when running the script directly.

.. GENERATED FROM PYTHON SOURCE LINES 98-107

.. code-block:: Python


    if __name__ == "__main__":
        show_m = window.ShowManager(
            scene=scene, size=(800, 500), title="Impostor and Mesh Ellipsoids"
        )
        try:
            show_m.start()
        finally:
            show_m.close()



.. image-sg:: /auto_examples/04_demos/images/sphx_glr_viz_ellipsoids_001.png
   :alt: viz ellipsoids
   :srcset: /auto_examples/04_demos/images/sphx_glr_viz_ellipsoids_001.png
   :class: sphx-glr-single-img






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

   **Total running time of the script:** (0 minutes 0.186 seconds)


.. _sphx_glr_download_auto_examples_04_demos_viz_ellipsoids.py:

.. only:: html

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

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

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

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

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

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

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


.. only:: html

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

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