-------------------------------
Conics from Circles (Animation)
-------------------------------

.. image:: render.gif
    :width: 500px
    :align: center

This example demonstrates an animation illustrating
the construction of an ellipse using circles
in the Euclidean plane.
You can see the full code at
:download:`conics_from_circles.py <../../../../../examples/blender/geometry/conics_from_circles.py>`.

.. contents::
   :local:
   :backlinks: none

Setup
=====

We start off by importing the necessary libraries.

.. literalinclude:: ../../../../../examples/blender/geometry/conics_from_circles.py
   :language: python
   :start-after: [setup-1]
   :end-before: [setup-1]

We are also going to clear the whole scene and create the geometry we will be working
in.

.. literalinclude:: ../../../../../examples/blender/geometry/conics_from_circles.py
   :language: python
   :start-after: [setup-2]
   :end-before: [setup-2]

Calculations
============

Now we are going to define the calculations necessary
for this visualization. First we define a function calculates
a smaller circle centered on the constructed ellipse and tangent
to the larger circle.

.. literalinclude:: ../../../../../examples/blender/geometry/conics_from_circles.py
   :language: python
   :start-after: [calculations-1]
   :end-before: [calculations-1]

Then we are going to define the larger circle
with a specified center (F2) and radius, as well as a point F1.

.. literalinclude:: ../../../../../examples/blender/geometry/conics_from_circles.py
   :language: python
   :start-after: [calculations-2]
   :end-before: [calculations-2]

Visualization
=============

Now we can begin with the visualization process.
We start off by setting up the camera and configuring
some render settings.

.. literalinclude:: ../../../../../examples/blender/geometry/conics_from_circles.py
   :language: python
   :start-after: [visualization-1]
   :end-before: [visualization-1]

Next we create materials and colors.

.. literalinclude:: ../../../../../examples/blender/geometry/conics_from_circles.py
   :language: python
   :start-after: [visualization-2]
   :end-before: [visualization-2]

And now we can visualze the objects in Blender.

.. literalinclude:: ../../../../../examples/blender/geometry/conics_from_circles.py
   :language: python
   :start-after: [visualization-3]
   :end-before: [visualization-3]

Animation
---------

Finally, to get the animations we first define
the following function.

.. literalinclude:: ../../../../../examples/blender/geometry/conics_from_circles.py
   :language: python
   :start-after: [animation-1]
   :end-before: [animation-1]

And then set some animation settings.

.. literalinclude:: ../../../../../examples/blender/geometry/conics_from_circles.py
   :language: python
   :start-after: [animation-2]
   :end-before: [animation-2]