anchor.diff:  parameters and get lovely shifting rainbow cues, as shown in the
   <<effects#oscillator-effects,effect examples>>.
   
  -== Direction Parameters
  +== Movement
  +
  +There are three different kinds of parameters which tell fixtures how
  +to move. They differ in the way that you express direction or aim.
  +
  +=== Direction Parameters
   
   Direction parameters are one way to tell a group of fixtures to point
  -in a particular direction, or move in unison or in a coordinated
  +in a particular _direction_, or move in unison or in a coordinated
   pattern. They are used with <<effects#direction-effects,Direction
   Effects>>. (<<parameters#pan-tilt-parameters,Pan Tilt Parameters>> are
   the other way to work with this kind of effect.) The basic way to
  
positive.code: parameters, as shown in the
  <<effects#spatial-effects,effect examples>>.
  
  == Digging Deeper
  
  For more details, see the
  http://deepsymmetry.org/afterglow/doc/afterglow.effects.params.html[API
  documentation].
  
  #### License
  
  +++<a href="http://deepsymmetry.org"><img src="assets/DS-logo-bw-200-padded-left.png" align="right" alt="Deep Symmetry logo"></a>+++
  Copyright © 2015 http://deepsymmetry.org[Deep Symmetry, LLC]
  
negative.code: the show variable was stored) or <<oscillated-parameters,oscillated
  parameters>>.
  
  === Aim Parameters
  
  Aim parameters are a way to tell a group of fixtures to aim at a
  particular _point_ in space, or track something in unison or in a
  coordinated pattern. They are used with <<effects#aim-effects,Aim
  Effects>>. The basic way to create one is to call:
  
  