A flap contains more info and more than just the pulled out values will make significant changes to the effect.  While it's not ideal to use this inside of a project, it is perfectly suitable for creating some pre-rendered animation frames to use later that end up using infinitely less CPU and and memory (since nothing is calculated in realtime if it's just playing back an animation).  

However, even as unoptimized as it is, it still runs at 15-30 FPS as it is now on an intel Atom dual core ate 1.2Ghz (which effectively means it's running at 600mhz on a RISC processor and no GPU assistance from what I understand of the VM).  

After all these years, this effect is still cool to look at and fun to apply to various kinds of graphics to achieve interesting results when combined.  

For fun, you can change the MAKE SCANLINES script to make vertical slices and change the demo script to affect Y origin instead of X origin.

Or if you're just lazy, rotate the entire holder playfield sideways and that works too.  :p

Enjoy...this will be included along with samples of where this is useful and how fast it runs after rendered (instead of running real time as a prototype) in Etoys Club 1 to be coming out...um...when I can finish it!  :)

​
​