This diagram shows how the patterns are formed. A curve is divided by an input spacing and get a series of points at equal intervals. Move them along the direction of normal and length of curvature of the adjacent points to obtain a new curve. Iterate this process continuously to get the final result. In this case, curves will always end in a shape of growing spiral like mushroom cloud after explosion. The same works among surfaces: uv points move along the distance of medium curvature and direction of  normal of the adjacent points to get a new surface. Iterate this process continuously to get the final configuration. The surfaces look more complicated and chaos than curves, yet still generate interesting and beautiful patterns.