    The keyword 'omega' followed by a float value may be added to change the
 turbulence calculations.  Each successive octave of turbulence is multiplied
 by the omega value.  The default 'omega 0.5' means that each octave is 1/2
 the size of the previous one.  Higher omega values mean that 2nd, 3rd, 4th
 and up octaves contribute more turbulence giving a sharper, 'krinkly' look
 while smaller omegas give a fuzzy kind of turbulence that gets blury in
 places.

