As I understand it, he hasn't hand crafted anything, but created an engine that understands Daggerfalls' data. So by definition if Privateers hold works, many other things will start to fall into place.
But I know nothing about how its actually done :blink:
That is correct. In fact I expect the second demo to be able to display almost any dungeon, city or interior except for a few features (such as water). Privateer's Hold is a testing grounds, its easier to test one dungeon then to say - "here's every dungeon, hope it all works" right away.
And also remember that I've been building the engine, getting all the file format parsing, building collision systems and getting game play features to work - but it is general work, not specific to this dungeon.
And while my DarkXL engine was a good base, the way rendering, collision, player physics and game play works in Daggerfall is quite different. So really all the non-core elements had to be done from scratch. But having a good framework and low level systems in place certainly helped.