gtkradiant technique i use often that I'm not sure if many others use: shearing

[Acrobat]

http://www.quakewiki.net/archives/speedy/tut_pipe.htm

[Lazarus]

interesting, I can understand why you post this, but with CPU / GPU's nowadays, i doubt true patches arent a problem for the game to render. It also gets really messy if you want a very detailed pipe, plus texturing can become a real pain.

[Acrobat]

I don't use it for pipes. Mostly for terrain.