The technique is called "sine puke", and it works by starting with a gradient (in this case a rainbow) and warping the domain when drawing that gradient by sine functions repeatedly (check the for loop)
In the fluid demo I blend new frames with the previous so you get this slower, softer pattern
http://thebookofshaders.com/edit.php?log=200806194314
The technique is called "sine puke", and it works by starting with a gradient (in this case a rainbow) and warping the domain when drawing that gradient by sine functions repeatedly (check the for loop)
In the fluid demo I blend new frames with the previous so you get this slower, softer pattern