anchor.diff:  |=======================================================================
   
   Collectively, `x`, `y`, and `z` specify a three-dimensional vector in
  -the light show’s [[frame of reference|show-space]] telling the lights
  -which direction they should point. The absolute magnitudes of the values
  -are not important, it is their relative sizes that matter. The default
  -of `[0, 0, 1]` means the lights point neither left nor right, neither up
  -nor down, and straight towards the audience. `[1, 0, 0]` would be
  -straight right, `[-1, 0, 0]` straight left, `[0, 1, 0]` straight up, and
  -`[0, 1, -1]` up and away from the audience at a 45° angle.
  +the light show’s <<show_space#show-space,frame of reference>> telling
  +the lights which direction they should point. The absolute magnitudes
  +of the values are not important, it is their relative sizes that
  +matter. The default of `[0, 0, 1]` means the lights point neither left
  +nor right, neither up nor down, and straight towards the audience.
  +`[1, 0, 0]` would be straight right, `[-1, 0, 0]` straight left, `[0,
  +1, 0]` straight up, and `[0, 1, -1]` up and away from the audience at
  +a 45° angle.
   
   All of these parameters, except for `frame-dynamic`, can themselves be
  -dynamic parameters, such as show link:#variable-parameters[variables]
  +dynamic parameters, such as show <<variable-parameters,variables>>
   (with the convenience shorthand of just passing in the keyword by which
  -the show variable was stored) or link:#oscillated-parameters[oscillated
  -parameters].
  -
  -[[aim-parameters]]
  -Aim Parameters
  -~~~~~~~~~~~~~~
  +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. The basic way to create one is to call:
   
  -code,clojure------------------------------------------ code,clojure
  +[source,clojure]
  +----
   (afterglow.effects.params/build-aim-param)
  -------------------------------------------
  +----
   
   By itself this call would simply return a non-dynamic point telling
   fixtures to aim directly at a height of zero, centered on the X axis,
  
positive.code: 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 link:#variable-parameters[variables]
  (with the convenience shorthand of just passing in the keyword by which
  the show variable was stored) or link:#oscillated-parameters[oscillated
  parameters].
  
  [[spatial-parameters]]
  Spatial Parameters
  ~~~~~~~~~~~~~~~~~~
  
  Spatial parameters allow you to base an effect parameter on the physical
  arrangement or relationships between fixtures in your light show. The
  way to create one is to call:
  
  code,clojure------------------------------------------------------------------
  code,clojure
  (afterglow.effects.params/build-spatial-param fixtures-or-heads f)
  ------------------------------------------------------------------
  
  The required parameters are the fixtures and/or heads over which you
  want this parameter to be calculated, and a function which, when invoked
  
negative.code: particular direction, or move in unison or in a coordinated pattern. The
  basic way to create one is to call:
  
  [source,clojure]
  ----
  (afterglow.effects.params/build-direction-param)
  ----
  
  By itself this call would simply return a non-dynamic direction telling
  fixtures to point directly at the audience. However, you will use one or
  