Hi!
I would like to introduce you to this project I've been working on for the last two years.
It's a CSG level editor plugin for Unity that performs CSG in real-time!
But instead of just telling you about it, let me just show you a couple of things you can do with it ..
Interested?
You can find more information on the project page!
Here's a youtube with the plugin in action!
Thanks for your time!