How do I convert an svg (or a plane) into a rounded mesh? How can I smoothly extrude a plane or an svg curve into a circular/rounded mesh? if I simply import an svg and extrude it and then add a subdivision surface modifier, it makes a big mess. I need a way to take a flat complex 2D object and extrude bit by bit systematically while changing the diameter of each extrusion (layer apon layer). I would hope it would end up looking like the semicircle in the photo (though using more complex 2D shapes though). I want to make the bottom image into a semicircular mesh to make it look like the top image. 


Any advice?
The manual way of doing this would probably be to extrude it up and then use the"Shrink/Fatten" (Alt+S) tool which scales each Vertex/Edge/Face along its normal which should give you something you might be able to work with.

I wouldn't be surprised if there was already a tool or an add-on to do this more or less automatically but sadly I don't know it