Trenchbroom is a powerful tool for quickly assembling a Quake map, and with the HammUEr plugin for UE4 importing those levels is as easy as the push of a button once you understand a few basic rules.
Я просто тренчбрум как редактор для кваки запомнил, с хаммерюр смешно, и тут сурс проект затесался.