How do I smooth textures on a cylindrical brush?

Big Lou

L3: Member
Mar 17, 2008
120
27
I have a few cylindrical brushes in my map, and on some of them, the lighting is smoothed out so that it looks round. However, on others, each face has a different level of light and it looks more octagonal. Is there a texture property to make the lighting more smooth and appear round?
 

TotalMark

L6: Sharp Member
Feb 13, 2008
331
78