Are the characters based on real people? The art for Subete Ga F Ni Naru is much more "realistic" that most of the anime that's been coming out lately. It seems to me that each character is unique enough that they could be based on real life "models".
Is there any documentation or word from the creators if this is the case and if it is, who the original models were?

EDIT: in answer to the request to define reality: as you can see below, the art does not rely on different hair colors or hair styles to differentiate the characters. Each character has distinct facial features that reflect reality rather than an moefied idealized anime world.
As far as I know, this is mostly due to the chara-designer's style, Inio Asano. He doesn't take his designs from real people (or at least he doesn't say so), yet his works all have this realistic and very diverse type of people.

As opposed to many anime chara-designers, he's not an animator, but a mangaka, with a very detailed, realistic style, as you can see below:





He drew the original chara-designs and character sheets that were used by the animators at A1-Pictures for The Perfect Insider, and that's probably that style you noticed. If you're curious, his works are critically acclaimed (and not only for the crazy art), with mangas like Solanin or Good Night Punpun.

Even though, you can clearly see how his raw style evolved to a more simple, and "round" style when it wad adapted, but it still keeps this realistic aspect. 

Hope it answered your questions, at least partially. Unfortunately, I couldn't find word from Asano on these specific designs.