I used TrenchBroom[1] to build the levels. It was initially created to build Quake maps but now supports many derivative games like Half-Life, too. I can't spea

I used TrenchBroom[1] to build the levels. It was initially created to build Quake maps but now supports many derivative games like Half-Life, too. I can't speak highly enough of it; it's really really good! [1] https://trenchbroom.github.io/ https://trenchbroom.github.io/