I don't think I'm returning into that cave again (except maybe to reuse the assets, etc.)
Also, here (https://blenderartists.org/forum/showthread.php?448304-The-Rebels-New-Base&p=3300539#post3300539) is the related post on Blender Artists with the thanks, the attributions, and a bit of a background story, and here (https://www.dropbox.com/s/jjl0k0ucrnii3na/RebelsNewBase4K.png?dl=0) is the original 4K render in the PNG format (not sure if the Dropbox link will work, apologies if it doesn't).
Technically, this has been the worst torture one can subject Blender to: a scene set inside a large mesh, lit by multiple tiny sources (and a particle system, of all things!), with no environmental lighting/HDRI (does anyone have a HDRI for a cave?). Even so, having invested in a Radeon Pro with 8GB of VRAM, 1000 samples and approx. 16 hours gave a decent result (with the denoising). Is it just me, or is it really better to render in a large format (like 4K), and later compress it in GIMP?
pointoflife14 Oh yes, and that female officer in the chat window was rendered in a separate .blend file, and then imported using the images-as-planes add-on.
pointoflife14 Yes and no: I faked the volumetric cones for the spotlights, using a separate scene rendered with Blender Internal, and then composited it on top of the rest. Other than that, no: just Cycles, and a lot of time and RAM. Brute force. :-)
did you render this in layers and then composite together?