Red_Fist wrote:One of the main things for UDK or a new editor, that gets me, is how you can now just shove an add brush in open space. I think that was the way Quake1 was.
Yep, additive CSG instead of subtractive CSG. You start with an empty void instead of a void of solid matter. Personally, the subtractive system got me into map-editing, but it seems the general consensus is more in favour of additive engines.
The additive system has been a possibility in Unreal 227 for several years now too