In prior editors, at least for UT99 and UT 2004, there was a custom brush pack made by a guy named Tarquin that included a Toroidal brush. It was really great and I used it to make curved ceilings for curved (hollow cylinder portion) hallways. Is there anything like that for UE4?
://wayback.archive.org/web/20050503202259/://www.planetunreal/Tarquin/docu.torus.html
://wayback.archive.org/web/20050503202259/://www.planetunreal/Tarquin/gif/bb.torus.32.gif
://wayback.archive.org/web/20050503202315/://www.planetunreal/Tarquin/gif/screen.torusitem.500x280.jpeg