waveform attribute
// 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