Making a solid

I am looking for a way to make this surface a solid, but instead using Offset I’d like to have a elipsoidic interior of a solid. What would be the idea to make it work? Below is the 3dm. file

kompozicija. jungimas.3dm (1.7 MB)

do you have kind of minimum / maximum wall thickness ?

did you see this video / approach:

maybe a workflow like this:
use the initial curves
_offset (i used 20, the red wavy curves)
_rebuild (the green smooth curves)
_loft (the inner surface from green curves)

to get the final solid
_boundingbox
_solid
(delete unneeded volumes)

please provide more info if you have more requirements / conditions

kompozicija. jungimas_02_tp.3dm (1.1 MB)

Thank you for your reply.

I’ve managed to solve on my own by simply:
1 Drawing 3 inward ellipsoids at bottom, middle and top of the object
2 Lofting ellipsoids
3 Capping the main object (the “Curtain”)
4 Splitting the “Curtain” with lofted ellipsoids