round tool
 

After using the round tool to round a corner on a nurbs cylinder (where the side meets the cap) I am left with a nicely rounded off edge but the side and cap faces dont match up to it. The front cap looks like a circle with an octagon inside of it. How do I finish this operation so that it is seamless? Ive pressed 3 on the keyboard to smooth the display but that doesnt work. pic attached.

Chances are you just need to set the NURBs tesselation so it will render properly.

Change the tool set from modeling to rendering in the drop down box at the top left corner. Then select the NURBs object, and select Render > Set NURBs Tesselation from the top drop down menu. This will do some calculations and even though the object may not look "complete", when you render it will look as the green outline indicates it will look.