Reference:Ripples Pattern

The ripples pattern was originally designed only to be used as a normal pattern. It makes the surface look like ripples of water. The ripples radiate from 10 random locations inside the unit cube area <0,0,0> to <1,1,1>. Scale the pattern to make the centers closer or farther apart.

Usually the ripples from any given center are about 1 unit apart. The frequency keyword changes the spacing between ripples. The phase keyword can be used to move the ripples outwards for realistic animation.

The number of ripple centers can be changed with the global parameter

global_settings { number_of_waves Count }

somewhere in the scene. This affects the entire scene. You cannot change the number of wave centers on individual patterns. See the section Number Of Waves for details.

When used as a normal pattern, this pattern uses a specialized normal perturbation function. This means that the pattern cannot be used with normal_map, slope_map or wave type modifiers in a normal statement.

When used as a pigment pattern or texture pattern, the ripples pattern is similar to normal ripples but is not identical as are most normals when compared to pigments.

ripples pattern used as pigment and normal respectively