// you can specify a waveform if patterns are used with blend maps.
// Especially useful for normals
// Note most patterns have default waveform ramp_wave
  ramp_wave         // linear raising from 0 to 1 and returning abrupt return
  //triangle_wave   // linear upwards and downwards
  //sine_wave       // sine waveform
  //scallop_wave    // absolute value of sine wave
  //cubic_wave      // cubic curve from 0.0 to 1.0
  //poly_wave 0.5   // exponential function