Project any lines from a Top view ?

As your volume is very thin copy move the top surface...

And after maybe FatLines by Max Smirnov for some fantasy...



Maybe after extrude the curves for have a volume & Boolean Diff by a curve for be smaller then original volume
and make a boolean Diff


http://moi3d.com/forum/index.php?webtag=MOI&msg=7594.31