Actually you can work offline in the Editor, it's the initial install and set-up that requires a connection. And even then per the UE forums you can use a connected computer with an external hard drive to install on a non-connected computer:
"You can just install the engine on any internet-connected PC (it doesn't need to be capable of running UE4, only the launcher) and copy it over (from C:\Program Files\Epic Games\4.x) to an external drive, transfer it to your PC, and then run Engine\Binaries\Win64\UE4Editor.exe (might want to create a shortcut). It doesn't actually require the launcher or any kind of authentication to run, as the editor is entirely self-contained.
You'll have to repeat the process for engine updates, though there will be less stuff to download if you use the same computer again and it still has everything installed.
If using another PC is not an option for some reason, you're out of luck as even the source code requires downloading some dependencies from external servers (which Epic themselves can't legally host)."
Unreal Engine (and Unity as well) are made to work with most DCC apps and their more esoteric siblings such as; Realflow, World Machine, Substance designer, etc. The output can be 4x's the screen resolution, including 4k imagery, and it happens in real-time (or very near at higher resolutions). Granted, the minimal specs for your hardware to do something like the "Kite Demo", as in this video:
http://www.bing.com/videos/search?q=the+kite+demo+4k&view=detail&mid=94BEC44D4E6AF5B5E99194BEC44D4E6AF5B5E991&FORM=VIREThe recommended computer is a six core i7, 32 gigs of system ram, and a upper level gaming video card. The link above is using one GTX 980ti with 6 gigs of GDDR5 ram (no SLI at present). TheBadger is so right about the potential here. With the recent postings by Digital Guru showing how to export a TG terrain out to Mudbox (as well as Maya, Max, etc), hopefully it won't be too long before we can use TG with one of these great game engines!
