A simple self-similar fractal. Similar to a Tree — in particular it's very similar to the Pine, but with a tilt before drawing the next segment.

to fern :segment :curve :angle1 :angle2 :ratiobranch :ratiostem :limit
penwidth :segment/4
ifelse :segment>:limit [
color [60 40 20]
rt :curve
fw :segment
lt :angle1
fern :segment*:ratiobranch :curve :angle1 :angle2 :ratiobranch :ratiostem :limit
rt :angle1
fern :segment*:ratiostem :curve :angle1 :angle2 :ratiobranch :ratiostem :limit
rt :angle2
fern :segment*:ratiobranch :curve :angle1 :angle2 :ratiobranch :ratiostem :limit
lt :angle2
pu bw :segment pd
lt :curve
] [ 
; leaf
penwidth :limit 
color [20 80 20]
fw :segment bw :segment]
end
fern 60 7 80 80 0.5 0.8 2

External Links

• Wikipedia: Barnsley Fern
• Wikipedia: Iterated Function System
• secretGeek: Fractals in logo, 2007