How to render images with curves "properties"?

I’m having a trouble on rendering image with poly line curves which I would use in another software like Adobe Illustrator. However, I always ending up with straight plain image rendering file with no other properties information.
or perhaps, I am doing it wrong? or perhaps, I should use specific plugin?

The thing is, when I save the file…and open it in Adobe Illustrator, I can’t select the curves because it’s an image file(like JPEG, GIF, TIFF, etc)…it would be different story if I could save it into .AI, or even .PDF because they also import polylines layer.
I need to be able to select the curves in another programs, so I can set “Line-weights”.

The curves post effect doesn’t provide vector information for curves.

that’s what i meant.

a solution would be to make a 2d drawing in rhino first in the same perspective view and overlay this with the rendered image.
just an idea…
or look into penguin render which gives toon render options.

Does Penguin render generate vector lines?

I was thinking that might be the only “manual” solution…I just don’t like to scale it in illustrator.