This is a module from Vanishing Point''s $$ ''Maintenance Tube'' kit. ST fans might call it a ''Jeffries''. The doors / hatches open/close progressively, which is a neat feature. Default size is crawl-space. 150% scale is walk-through.
But, the smart floor and ceiling ''lighting panels'' did not suffice to illuminate renders. They had to become full-on ''emitters''.
After much, much Googling, I read to dial-up their Ambiance_Value in Materials'' ''Advanced'' settings. Dial default one (1) unto 50~~99, then render with Superfly.
After some trial and error, I got this. Beginners Luck, as another 4~~5 hours passed before I could get back to it...
My best guess seems to be for the lights'' D/H/A to be pale blue, with reflection to multiply by lights, not object colour.
One snag is a lot of material menu values seem to mutate when your back is turned. And, renders are ''noisy'', so I had to double the ''pixel'' count...
I learned to render ''progressive'', to allow me to cancel early if no lights within...
