How Infinity War Transformed Josh Brolin Into Thanos

One of the most important elements to get right in creating a computer-generated character is the eyes. The cliche goes that eyes are windows to the soul, which is really just a way of saying they convey subtlety. They squint or widen to show fear, shock, or focus, conveying emotion through tiny microexpressions — and when it comes to a monstrously evil figure like Thanos, seeing those emotions can make all the difference.

"Even though he's despicable on so many levels, there's a part of Thanos that is very empathetic," said Anthony Russo, the movie's co-director. "He has a very complex inner life, and he's not all bad. Josh is a performer who's capable of delivering that kind of complexity, where you have that level of violence in him, but at the same time you have that level of sensitivity."

All of that would be for nothing if Digital Domain proved incapable of mapping Brolin's face onto a monster, but the studio was fortunately up to the task.

"What we really focus on is the eyes at Digital Domain, and there's a ton of work, and a huge amount of detail around that," said Port. The company, he added, doesn't treat the eye as one object, but rather as layers of intersecting objects — eyelids, conjunctiva, and the thin layers of the eyeball itself. All of this goes a long way toward making Thanos feel like a real person — and that realism, in turn, makes him so much scarier.