This operator computes 2D, anti-aliased cellular noise suitable for shading. It is similar to Voronoi noise in that it overcomes some of the artifacts of Worley noise, such as getting even widths along the cell boundaries. The significant advantage of this noise over both Voronoi and Worley is that it is anti-aliased.
Cellular noise works by scattering points randomly through space according to a nice Poisson distribution, generating cell-like patterns.
You can look at dist1 as the amount of generated noise (see other pattern generators such as Boxes or Stripes), which can be connected to a mixing bias (see Mix), a displacement amount (see Displace Along Normal), or other float inputs.
If the s and t inputs are not specified, global variables appropriate to the current context will be used instead, as follows: (s,t) in the shading contexts; (P.x,P.y) in the geometry and particle contexts; and (X,Y) in the compositing context.