Practical Algorithms for 3D Computer Graphics, 2nd Edition

488 11. Algorithms for procedural textures

Figure 11.31: Scaly skin surface s h owing ridge featur es at decreasing scales.

11.2.27 Faceted

Crumpled surfaces exhibit features of a combination of basic rough surfaces

with decreasing amplitudes and reducin g scales. A faceted texture us es the

same idea of summing effects at decreasing scales but without changing the

amplitudes. Flat surfaces (which give the texture the appearance of some sort

of naturally occurring mineral) are produced by quantizing ∆n using integer

arithmetic before mixing it with the su r face normal.

The Pea texture (11.2.22) forms the bas is for this texture. This time the

hemispherical ...