if you want to see the real making of blade runner, take a look at Jodorosksy's dune.
https://en.wikipedia.org/wiki/Jodorowsky%27s_Dune
its a stillborn adaption of dune, but it more or less pioneered the entire alien, blade runner, aesthetic. even 2001. basically all those 80s sci fi futurism movies were based on this stillborn movie.