No, it's both simpler and more complex than that.
Take one of these:
https://www.dropbox.com/s/lki7pyoacusfxhy/whirlpool_4x4.png
And create an NPC that does this:
Image overlay 1,setx 316 sety 300 setalpha 70 layer 0 rotate -360 4000 loop -1
Image overlay 1,setx 320 sety 300 setalpha 70 layer 0 setangle 240 rotate -360 3000 loop -1
Image overlay 1,setx 318 sety 304 setalpha 70 layer 0 setangle 120 rotate -360 3500 loop -1
Use the text in each command for the Image Overlay script, assigning it the image I've provided.
[Last edited by mrimer at 06-25-2014 10:39 PM]