When designing macros I have seen occassions where the macro was
specified like this example shows:

 #macro Pattern ()
      granite
        color_map{
                  [0.5000 rgb 0]
                  [0.5001 rgb 1]
                 }
            warp { turbulence .03 lambda 1.4 omega 2.0 octaves 5 }
       translate z*3
    scale <2, .5, 2>
  #end

 Note the absence of any identifiers inside the macro parenthesis ( )
 This was later used in a media statement as a density pattern.

  My question then is this. Why go through the trouble of making a macro
with no customizable attributes, for a one time use, when is would seem to
me that a simple #declared density would serve the same purpose.

  From where I sit there is no real difference from the above example
and the one that follows.

 #declare Pattern =
  density {
      granite
        color_map{
                  [0.5000 rgb 0]
                  [0.5001 rgb 1]
                 }
            warp { turbulence .03 lambda 1.4 omega 2.0 octaves 5 }
       translate z*3
    scale <2, .5, 2>
  }

  Would they not function the same way and is there anything to suggest
that the macro offers any advantage the way it is illustrated above ?



--
Ken

mailto://tylereng@pacbell.net

Post a reply to this message