helix
=====

.. image:: images/helix.jpg

.. py:function:: helix(pos=vec(0,0,0), axis=vec(3,0,0), color=color.red)

   :param pos: Position of left end. Default <0,0,0>.
   :type pos: vector
   :param axis: Extends from *pos* to other end. Default <1,0,0>.
   :type axis: vector
   :param color: Default *color.white*.
   :type color: vector
   :param radius: Radius of the helix.  Default is 1.
   :type radius: vector
   :param thickness: Diameter of the cross section of the curve. Default is *radius/20*
   :type thickness: scalar
   :param length: Length of axis. Setting length sets magnitude of axis. Default is 1.
   :type length: scalar
   :param coils: Number of coils.  Default is 5.
   :type coils: scalar
   :param size: Length, height, width of a box surrounding the cylinder. Default is <1,1,1>.
   :type size: vector
   :param ccw: If *ccw* is *True* the helix winds counterclockwise (default).
   :type ccw: boolean

By setting size appropriately one can make the cross-section of the helix elliptical instead of circular.

Because a helix is constructed from a curve, it has the same limitations as curve: a helix cannot be compounded, cannot be transparent, and cannot have a texture.
   
Attributes used less often:

.. py:function:: helix(canvas=mycanvas, make_trail=True, emissive=False )
   :noindex:

   :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 visible: If False, object is not displayed.  Default: True
   :type visible: boolean
   :param canvas:  Default is *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

  
.. seealso:: Rotation; :doc:`color<color>`; :doc:`emissive<emissive>`; :doc:`canvas<canvas>`