As you can tell by the subject, is it possible to put Cylinders into custom maps? If so, how?

Make a square brush, as you would normally.

Then with it still selected, go to Patch>Primitives>Cylinder.

That will turn the select brush into a Cylinder, you can also, in the Patch menu, click "Cap" or Shift+C to put ends on it or Thicken or Shift+CTRL+T to give it thickness.

I thought thickness was was T not C? Anyway, could be remembering wrong, my favorites are ] to make it more round (increase verts?) and [ to make it less round. I think you use ctrl+shift with those too. Also, I usually make those non-colliding then or detail at the least, especially if you have a lot of them. Tends to save me from dealing with errors as much.

I thought thickness was was T not C? Anyway, could be remembering wrong, my favorites are ] to make it more round (increase verts?) and [ to make it less round. I think you use ctrl+shift with those too. Also, I usually make those non-colliding then or detail at the least, especially if you have a lot of them. Tends to save me from dealing with errors as much.

Crap, updated that now, lol, it's T not C as MakeCents said.

might be worth noting there are two options for cylinders in radiant, the other one not mentioned here will give you a compile error

What these guys have posted is the "correct" way

the other one not mentioned here will give you a compile error

i always wanted to know the reason of that