Rounded walls

[mepwn12]

I was wondering, since you can make rounded pools.
Is it possible to make a custom wall that is rounded with a slider like at the pools?

[lorenrose1013]

I know that with pools, only the top appears to be rounded, because if you go down a floor you see that the walls are straight. I think that this would require new meshing and you would have to make it into a fence of some sort.