Features and Columns · Movies

Pore Than Meets the Eye: Why It’s So Hard to Make CGI Skin Look Real

Looks like the uncanny valley was only … skin deep.
Alita Battle Angel CGI Skin
Twentieth Century Fox
By  · Published on September 17th, 2021

Welcome to The Queue — your daily distraction of curated video content sourced from across the web. Today, we’re watching a video essay on why it’s so hard to make CGI skin look realistic.


First introduced in the 1970s by Masahiro Mori, then a robotics professor at the Tokyo Institute of Technology, the uncanny valley describes the unsettling revulsion produced by characters and robots who strive and fail to attain a convincingly lifelike appearance.

You can always tell when something exists in the uncanny valley. But identifying the specifics of what, exactly, makes a character feel “wrong” is not always so readily apparent. While eerily wet eyes or unexpectedly human teeth are dead giveaways, one subtler element in the uncanny valley soup is skin. Ignoring key humanizing details can make digitally rendered skin feel lifeless and plastic. As if some synthetic android was making an unsuccessful attempt to pass rubber off as flesh.

The Scorpion King in The Mummy Returnsa fully CGI character animated after the likeness of Dwayne “The Rock” Johnson, is an infamous example of the uncanny valley’s horrific possibilities. One of the contributing factors to the character’s human-but-not-quite appearance is the eery unbelievability of his skin. Set beside the title character of the 2019 film Alita: Battle Angelit’s clear that today’s blockbusters have more or less cracked the code on real-looking CGI skin.

The video essay below offers a breakdown of all the micro-considerations that allow modern CGI artists to create convincing renderings of human skin. It covers everything from pore mapping and subsurface light diffusion to accurately accounting for blood flow-led color chances. It offers a brief introduction to how far we’ve come in the last decade or so. And if one is to venture into the uncanny valley, or to celebrate its diminishing presence on the big screen, it is vital to get granular. Because it turns out that most of this crucial detail work is, in fact, skin deep.

Watch “Why it’s so hard to make CGI skin look real”:


Who made this?

This video about CGI skin is by Vox, an American news website owned by Vox Media, founded in 2014. Vox produces videos on news, culture, and everything in between. This video was produced by Phil Edwards with art direction by Estelle Caswell and story editing by Bridgett Henwood. You can subscribe to Vox on YouTube here. And you can follow them on Twitter here.

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Meg Shields is the humble farm boy of your dreams and a senior contributor at Film School Rejects. She currently runs three columns at FSR: The Queue, How'd They Do That?, and Horrorscope. She is also a curator for One Perfect Shot and a freelance writer for hire. Meg can be found screaming about John Boorman's 'Excalibur' on Twitter here: @TheWorstNun. (She/Her).