So much replies while i was fighting with the cables and driver of my old scanner, thank to everybody !
@RichI didn't thought about mathmap, that may be a cool idea
@BKHi forgot about that script i even have installed.
Sure it can work and thank to remind me that path suite will anyway come handy
@RobAthat seems perfect.
From the description you give there is nothing to tweak it already does what i was looking for and much more.
And your examples are really exciting, i am going to try at soon i finish the reply @Ljleyk
I know that Gmic filter since i requested,there the idea was a bit different
= fill a selection or anyway outlines (clearly marked as in line art) with concentric shapes the closest identical to selection or outlines shapes the innermost rounded if needed.
I believe that if would have worked could be a killer filter for decorations and a lot of special effect
BUT ...doesn't work well:
too often many of the concentric lines get broken ,disjointed .and that really spoil the intended effect I did try to ask David to fix, but with no any luck
It sort of work only with most simple shapes (as your rectangle ) and even than with not all combination of thickness and numbers of concentric lines (and no way to guess which combination will work and which will result in series of disjointed lines )
Really a pity because in a framework as GMIC (Preview, possibility of multiple input/output, and with a bit of fiddling to animate the filters ) would be perfect