If you create a piece of art from a few scripts, is that your own work or not?
**Presuming this is for an upload here at WinCustomize**
Personally, I'd answer that as a 'no' ...as the scripts were not created by the wallmaker.
Whether it be the art itself, or the scripts to make it in a program [that uses scripts] to generate the art ~permission would still be needed from it's ORIGINAL author, although the call on the scripts issue would be a tough one as there'd be difficulty proving that a person actually made and/or used that script.
Unless, of course, if that script generated something unique and identical everytime it was used, and was identifiable as belonging to its original creator. 