This is really neat. I think CSG is one of the more intuitive ways to build 3d environments (especially 'indoor' ones). No geometry is ever destroyed in a proper CSG workflow. A hierarchy of brushes makes it possible to very rapidly iterate parameters like how long a hallway is or the time it takes to get from one objective to another. Often, you only have to apply a transform to a single brush to affect something that would take a non-CSG workflow an entire afternoon to recover from.

The current story with CSG around commercial game engines is pretty awful. Unity has some 3rd party options that can work well but they're also glitchy and don't integrate well with the other parts of the ecosystem. For a while I thinking about building my own CSG implementation but the exact things this project solved were what was stopping me. The EditorWindow integration stuff is not as scary to me (although it is painful). The advanced geometry and set operations is what kept me from trying. It appears that dragon has been (at least partially) slain.

That's why I integrated manifold into godot engine for constructive solid geometry!

https://github.com/godotengine/godot-proposals/issues/9711