As requested, here is a timelapse of a level being constructed in 3D. Its important to note that this is only about 2 hours of work, with a full level usually requiring around 12 hours-so we are at around 10% complete here.
But this gives a pretty good idea about how I work when putting together a level. From here, I would render out the animated areas, and put them into the engine. I will record that process when I get there. 🙂