I introduced recursion to my students today using fractal trees as an example. They got to learn about using `pushMatrix()`

and `popMatrix()`

with the power of using `rotate`

and `translate`

to avoid nasty trig stuff.

They asked about creating a sunset, and so we found `setGradient`

on the Processing website.

We added some Perlin `noise`

to make the tree flutter a bit.