Smoothing a surface
Some surfaces are meant to be round and curved. However this is difficult to accomplish in Radiant. This tool can make a surface look more curved than it is. (The surface itself will not at all become more curved, it just looks that way).. Here an example of a blocky model that could need some smoothing.
Select the surface for smoothing
First, select the surface You want to smoothen. Because the routine works on 1 surface only, You need to select, and smoothen, every surface seperately. You must select the current surface from the dropdown-listbox on the "Surfaces"-Tab.
Select the option from the menu
Once You have selected the proper surface for smoothing, select the choice from the menu: "Smooth current surface".
Not so blocky now..
As You can see on the resulting surface, it is not so blocky anymore..
Final result
When all surfaces are smoothed, the resulting model can look very different. Lights & shades look much better if a surface is supposed to be round..