http://www.strategycore.co.uk/xcom/pg/links
As you can see, there is one under dev using the quake 2 engine.
UFO Aftershock or Afterlight there was also aftermath. But from what you wrote maybe you mean more like Genesis?
Best bet, would be to look at the NWN (1) editors, Just ignore the fact that there are all Oldie worldie, and see how they did it, which is exactly how you descibe wanting to do it.
The first of the UFO seriers uses Tiled maps, but the second two use predefined landscapes.
As you can see, there is one under dev using the quake 2 engine.
UFO Aftershock or Afterlight there was also aftermath. But from what you wrote maybe you mean more like Genesis?
Best bet, would be to look at the NWN (1) editors, Just ignore the fact that there are all Oldie worldie, and see how they did it, which is exactly how you descibe wanting to do it.
The first of the UFO seriers uses Tiled maps, but the second two use predefined landscapes.