Noise modifiers are functions that apply a specific noise profile to a density function. Noise functions apply pseudo-random perturbations in 2D or 3D and are often combined or layered in octaves to generate interesting and complex shapes. Noise by definition adds a non-deterministic element to modelling.
Acropora provides three noise sources:
Volumetric noise sampling utlises several banks of randomly seeded volume data to generate surfaces. Typically in multi-octave noise layering the noise source is changed to give more variation and less repeatability. The user can control the quality of the noise at each octave.
Affect on surface quality at 5,7 and 9 octaves, respectively, of volumetric noise on a plane:
Affect of amplitude scaling on 6 octaves of noise:
Affect of frequency scaling on 6 octaves of noise: