The game that I'm making takes place in a series of small planes of existence connected by portals. I'm basically wondering which of the following three methods would be best.

a) Make new worldspaces (seems hard, I've heard its problematic)
Make more interiors, but give them a sky somehow
c) Make "floating cities" above Skyrim

Can anyone enlighten me on these options, potential pitfalls and such?

option a

pro's: allows you to build an entirely new world with your own weather, climate, landscape etc.

con's: there are bugs yet to be worked out with worldspaces, and requires multiple 3rd party software. fast travelling into your custom worldspace from a modded navmesh'ed cell will cause a strange elevation glitch where an invisible floor pushes you up hundreds of feet into the sky. multiple cells involving both interior and exteriors that are loaded with goodies will cause instant CTD in between loads on esp's and requires further flaming-hoop jumping (creating a script-travel "purgatory cell" to buffer in between each one)
the latter can be fixed by esm though


option b

you can make a fake exterior in an interior but i believe you cannot fully use weather systems, and obviously no terrain or proper LOD support either, so it would have to be small, as everything would have to be made with statics. you would also have to fake distant terrain somehow (possibly through use of clever fog + forced perspective optical tricks). interiors also seem to have a lower memory budget before hell starts to break loose on scripts and object loading. you also have a significantly lower budget for FX and lighting without the use of roombounds (which in itself is a double edged sword). roombounds are really only useful if you are making a typical linear dungeon. they are practically useless for open layouts



option c

floating cities gives you the advantage of building within the tamriel worldspace, but you have all the usual problems such as large statics not loading properly from distance. navmeshing could possibly become problematic depending on where you build (i would suggest picking as remote a location as possible, preferably uninhabited)




i would personally go with option a (as i am currently doing now). even though this option has the most potential problems, i think the trade-off is worth it and there are viable workarounds for most of the issues.

I think I'm going with option B. There would be no distant terrain, as the city I'm working on is actually its own plane of existence (in lore) so even if there were void, it wouldn't really matter. Also I have no need of weather. How do I make a sky appear in an interior then?

all i can say is keep it small. the performance budget is the biggest con for option b

The city is actually a series of small areas, it won't be a problem.
So, how do I add a sky?

open yuour interior cells edit window and click on the lighting tab.

you can check Show Sky. then pick the region which matches the type of sky you want (you can also create your own region and sky)

Cool! Eventually I want my sky to be a gigantic arch, as the plane of existence is a spinning ring world.