ring
====

..	image:: images/ring.jpg
..	image:: images/ringdiagram.png
	:width: 200px

.. py:function:: ring( pos=vec(0,0,0), axis=vec(1,0,0), radius = 2, thickness = 0.2. color=color.cyan )

   :param pos: Default <0,0,0>.
   :type pos: vector
   :param color: Default *color.white*
   :type color: vector
   :param axis: Perpendicular to plane of ring. Default <1,0,0>.
   :type axis: vector
   :param radius: Radius of the ring. Default 1.
   :type radius: scalar
   :param thickness: Half the diameter of the cross section of the ring. Default 0.1*radius.
   :type thickness: scalar
   :param size: Size of a box surrounding the object. Default <0.2, 2,2, 2.2>.
   :type size: vector

The *pos* of a ring is at its center.  The *axis* of a ring determines only the orientation of the ring; the magnitude of *axis* is ignored.  The default size of a ring is unusual: <0.2, 2, 2>.  The outer radius is *radius+thickness*, and the inner radius is *radius-thickness*.

Setting *radius* or *thickness* overrides *size*.  Size is < length, height, width>.  To make the ring oval, specify *size* with different height and width. 

Attributes used less often:

.. py:function:: ring( opacity=0.5, shininess=0.2, texture=textures.wood, make_trail=True, canvas=mycanvas, emissive=False )
   :noindex:

   :param opacity:  Default 1.0; Range 0-1.
   :type opacity: scalar
   :param shininess: Default 0.6; Range 0-1.
   :type shininess: scalar
   :param emissive: Default False. Object glows, losing all shading, if True.
   :type emissive: boolean
   :param texture: Default None. 
   :type texture: class element or path   
   :param visible: If False, object is not displayed.  Default: True
   :type visible: boolean
   :param canvas:  Default is :py:attr:`scene`.  
   :type canvas: object
   :param make_trail: If True, object leaves a trail when moved. See Attaching a Trail for more options.
   :type make_trail: boolean
   :param up: A vector perpendicular to the axis.
   :type up: vector
   :param group: The group to which this object belongs.
   :type group: object
   
.. include:: ./objectSeeAlso.rst