The blob variation pushes and pulls the plane to make it look like a blob. Specifically, it takes a sine wave, wraps it into a circle, and uses that to distort the plane. The pictures below show respectively a sine wave, a radial sine wave (one wrapped into a circle), and a circular dc_perlin texture before and after applying blob.
Blob works as a final variation (as was done above), but is not used very often since most fractal artists don’t want their results to look like a blob. Used as a regular variation, blob can produce effects ranging from flower shapes to wavy distortion to unique gnarls.
This flame uses the technique for plastic and oily flames: a blur iterated with spherical with a tiny amount of a distorting variation (linear for plastic and cross for oily). Here, the distorting variation is blob.
|variation amount||Scale factor for the output.|
|low||Proportional height of the troughs of the waves. It is typically set less than 1, though this is not required.|
|high||Proportional height of the crests of the waves. It is typically set a bit larger than 1, though this is not required.|
|waves||Number of waves. Normally an integer; if not, one of the waves will be cut off.|
When low and high are both set to 1, blob is the same as linear. A useful technique is to change the linear in an existing flame to blob and set low and high to 1, so the flame doesn’t change. Then gradually decrease low and increase high to introduce distortion.