This is going to sound like a stupid question but I'm just not finding a solution in Radiant.

How the heck do you build non square/rectangular geometry, like a solid cylinder?

I'm not seeing anything in any of the tutorials i've come across, the curved sidewalk tutorial is the closest thing I've seen but I dont know if it'll adapt well to what I want to do.

Try options from "patch-primitives' tab. U can build cones, cylinders, arches , everything is rihgt there. U can build anything You want and only Your own imagination can block You in this.

Oh.. and You need a lot of time to know all of radiant's possibilities. There ia a lot of it

As he said, use the patch primitives, and thicken it to make it solid on the top, etc.

Regarding Infernal's extra info: I agree, Infernal. I have been mapping for CoD 1 for 2 years now, and constantly find new tricks and abilities. And remember, this is CoD 1 Radiant we're talking about here; there are so many new features in the new radiants!

Check this out, I put it together the other week to use as reference, it's the list of shortcut buttons:

thanks guys. Guess I haven't really given it enough time to find all of radiants little tricks and such. I really do need to thank the people who've submitted tutorials to this site, after reading the door/wind tutorial and a couple of the others ones I've already managed to build three joined rooms. All textured and lit too.

One other thing I see that Radiant does use something similar to UT's "static meshes" but Do the always show up in the editor as red cubes or am I doing something wrong?

It depends of how You setted Your viewport.

if You have "emntities" set as bounding boxes then all models will be shown as red cubes. (look for "view" tab and "entities as" in there") I have "entities as" set to "skinned" that means the models i've placed on the map are shown as they looking.

In other case red boxes are appearing when You input wrong name of entity (model) in "Entity properties" window (shortcut "N")