External light sources within buildings

[Goggs]

I often start a fire close to a shelter without a stove within it. Sometimes it'll be right outside the window of the building. However, when I step inside for a doze there's no sign of the fire burning outside.

[cekivi]

This is actually related to several other forum posts regarding looking through windows. I can't remember the technical reason but it has something to do with the Unity engine...

[hauteecolerider]

I think it has more to do with the fact that interiors are treated as separate worldspaces from exteriors. 

The exterior (say, Mystery Lake) is one huge map. Then you step through a door, experience a loading screen, and bam, you're in a separate map, albeit a much, much smaller one.

It would be difficult to have windows show the weather from a different map as a graphic element. Yes, we know how much daylight there is outside while we're indoors, or whether or not it's blizzard/fog outside (??? hours of daylight left). However, that's simple programming. Linking that to graphic elements and coordinating that with the exterior map is much more difficult, more involved, and requires more scripting. More scripting can cause choppy gameplay, lags in loading screens, etc. 

This is not limited to the Unity engine, either. I remember a major discussion around the Open Cities mods for Oblivion and Skyrim, which eliminated the loading screens for the cities and walled towns. However, it led to bugs with pathing, FPS drops, graphic glitches, and more. There was another mod in Oblivion that linked the windows to the weather outside - it would show the scenery and the weather of the exterior world. But it wasn't easy, and added tons more scripting for the game to handle. And those games run on the Havok engine. 

DISCLAIMER: I'm not a computer programmer. I just find this stuff interesting.