anchor.diff:  
   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. The basic way to create one is to call:
  +coordinated pattern. They are used with <<effects#aim-effects,Aim
  +Effects>>. The basic way to create one is to call:
   
   [source,clojure]
   ----
  
positive.code: every frame, or just once
  |=======================================================================
  
  Collectively, `x`, `y`, and `z` specify a three-dimensional point within
  the light show’s [[frame of reference|show-space]] telling the lights
  where to aim. If you need to convert inches to meters, which are the
  standard distance units in Afterglow, you can use
  http://deepsymmetry.org/afterglow/doc/afterglow.transform.html#var-inches[afterglow.transform/inches].
  
  All of these parameters, except for `frame-dynamic`, can themselves be
  dynamic parameters, such as show <<variable-parameters,variables>>
  
negative.code: 
  == Direction Parameters
  
  Direction parameters are a way to tell a group of fixtures to point in
  a particular direction, or move in unison or in a coordinated pattern.
  They are used with <<effects#direction-effects,Direction Effects>>.
  The basic way to create one is to call:
  
  [source,clojure]
  ----
  