From 2010 to 2019,

technology changed in major ways,

which had a huge impact on the movies we watched.

From realistic environments to convincing fake animals,

to aging and de-aging actors and even doubling them,

it almost felt like there was nothing CGI couldn't do.

Let's take a look at some CGI from the past decade

that took movies to the next level.

Who would have thought that a biopic

about Facebook cofounder Mark Zuckerberg

could also be a CGI marvel?

Armie Hammer played twins Cameron and Tyler Winklevoss.

Tyler Winklevoss: I'm 6-5, 220, and there's two of me.

Narrator: Actors playing double is nothing new.

Typically, when an actor plays two characters that interact,

filmmakers use techniques like split screens

and over-the-shoulder shots,

which this movie certainly used.

Just look at this shot, where the twins are walking together

but we don't see either of their heads.

That's because the movie used two different actors.

Actor Josh Pence served as Armie Hammer's body double.

Hammer's face was then grafted onto Pence's body

in post-production.

The two would switch off who would be Cameron

and who would be Tyler from scene to scene.

Face replacement didn't start with "The Social Network,"

but this movie was, at the time,

the first truly convincing version of the technology,

especially since it was a movie with no sci-fi elements.

Armie Hammer wasn't the celebrity he is today,

and for a while people actually thought

he was two different people.

These techniques paved the way for an entire movie

about doubles in the form of "Us"

and for Chris Evans to fight himself in "Avengers: Endgame."

This feat also involved face replacement

from Lola Visual Effects,

which took what it learned on "The Social Network"

and applied it to the Marvel Cinematic Universe.

Prior to his transformation into Captain America,

Steve Rogers is small and scrawny,

nothing like actor Chris Evans.

For some shots, actor Leander Deeny doubled

as the skinny Steve Rogers.

For others, the VFX team replaced Deeny's entire head

with Evans' head.

Evans would shoot the scene looking like himself.

Deeny would watch Evans perform the scene

and precisely mimic his every move.

The crew would shoot a clean plate with no character at all.

Then, VFX artists would place Evans' face over Deeny's.

But for most of these scenes,

the VFX team digitally shrunk Evans down.

For this, Lola Visual Effects

invented a new method for shrinking,

which it called "Steve slimming."

Lola Visual Effects' artists said they learned a lot

from this experience,

like how to highlight an actor's performance

without letting CGI get in the way.

That's a lesson they applied when de-aging

Samuel L. Jackson in "Captain Marvel."

Chris Evans wasn't the only Marvel hero

who went through a CGI transformation.

"Captain America: Civil War"

featured a de-aged Robert Downey Jr. as Young Tony Stark.

Lola Visual Effects once again stepped in here.

Some cases of de-aging involve a body double,

and others involve replacing the actor

with a digital double.

However, new technology allowed Downey

to perform the scene normally as himself.

VFX artists used digital compositing to de-age the actor.

This way, Downey could still perform the scene as usual

and the VFX team wouldn't lose the actor's many nuances,

which is a technological achievement

that helped three years later in "The Irishman,"

which we'll get to in a bit.

De-aging has become an essential process.

Changes can be as big as lifting skin

and as subtle as increasing light reflecting off skin.

One of the biggest challenges of de-aging

a well-known star is that audiences are familiar

with how they looked when they were younger,

especially with an actor like Downey,

who has been in movies since he was a child.

So the VFX team analyzed old footage of him

in 1987's "Less Than Zero," which helps explain

why this young version of Tony Stark was so convincing.

De-aging was not invented in this decade.

An early use came in 2006's "X-Men: The Last Stand."

But looking at the results from that decade to this one,

you can see just how much better it's gotten.

Technology can both de-age and age an actor.

Hayley Atwell was aged up for a pivotal scene

where she plays a much older Peggy Carter.

Once again, thank Lola Visual Effects

for this transformation.

Every movie is just an excuse for visual effects artists

to build on the visual effects work done before

and get better.

In an interview, Lola VFX artists said they believed

they spent so much time perfecting Carter's neck

that they didn't spend nearly enough time on her face.

Five years later, Captain America

would finally get to act his age in "Avengers: Endgame,"

as Chris Evans was aged up using a mix of CGI,

makeup, and a body double.

But this time, Evans wore neck prosthetics

so the VFX artists could spend even more time

perfecting his older face.

Thanks to motion-capture technology,

actors could show their full range of emotions

while being transformed into basically any kind of creature.

Mo-cap was honed in the 2000s

in the "Lord of the Rings" trilogy,

"King Kong," and "Avatar."

It became commonplace in the 2010s,

hitting its stride over the course

of the "Planet of the Apes" reboot trilogy.

Much of the work on all of these movies

was done by the famed visual effects studio Weta Digital.

By the time of "Rise of the Planet of the Apes,"

cameras were able to capture

the most subtle of movements and details,

which made the apes more believable.

And "Rise" was also the first movie

to ever shoot motion capture in a live-action location,

as opposed to just a bare soundstage.

This development would later help them

to shoot in even more challenging locations,

like the Vancouver rainforest

in "Dawn of the Planet of the Apes"

and on beaches and in deep snow

in "War for the Planet of the Apes."

It wasn't Andy Serkis'

only big motion-capture character of the 2010s.

Serkis played the menacing Supreme Leader Snoke.

He showed up as a hologram in "The Force Awakens"

and then in person in "The Last Jedi."

According to Industrial Light & Magic

creative director Ben Morris,

they didn't even have the tools

to make Snoke look this realistic in "The Force Awakens."

By the time "The Last Jedi" rolled around,

they were able to add so many details to the skin,

like age spots and veins.

The visual effects team shot Serkis

with high-resolution cameras

positioned at every conceivable angle

to create a digital clone of him.

As Serkis performed, they could automatically

capture every subtle facial move,

from how he smiles to how he furrows his brow.

They even studied the elderly to see how light

would realistically hit Snoke's skin.

The technology ILM developed in collaboration

with Disney Research has been used to capture many actors.

One of the most prominent: Josh Brolin as Thanos.

Look closely and you can see every crease,

every pore, of the "Avengers" villain's skin.

In the live-action "Jungle Book" remake,

actor Neel Sethi played Mowgli

and was the only human character in the film.

He acted on a completely empty soundstage,

besides these puppets and creature performers

that would then be digitally replaced

with the actual CGI characters.

The biggest breakthrough on this movie: muscle movement.

MPC Film developed new software

for animating an animal's muscle structure.

All of MPC Film's work directly contributed

to its work on 2019's "The Lion King."

The VFX artists perfected their already developed

muscle and movement simulations.

They also added more joints and bones under the skin

as a way to make the characters' movements more natural.

Otherwise, CGI creations run the risk

of being either too bouncy or too stiff when they move.

And the environments created for "The Jungle Book"

were made in virtual production,

which required virtual reality techniques,

allowing filmmakers to step foot in these environments

and better place their characters in them.

This was also used to a more advanced degree

in 2019's "The Lion King."

But with great CGI comes great responsibility.

This "Star Wars" prequel brought back the Empire's

sinister Grand Moff Tarkin.

However, actor Peter Cushing died in 1994.

So Industrial Light & Magic used CGI

to bring him back to life.

Another actor, Guy Henry, stood in as Cushing

and did his best Tarkin impression.

A mounted camera rig captured his facial movements.

Then, ILM used this performance as a guide

to digitally recreate Cushing.

The whole process took about 18 months to complete.

While Cushing's estate gave its blessing,

the decision was still controversial.

Should you bring back an actor from the dead?

This issue isn't going anywhere.

The upcoming Vietnam War-era drama "Finding Jack"

caused an uproar with news that it "cast"

a CGI-version of long-deceased Hollywood legend James Dean.

In "Blade Runner 2049," the VFX wizards at MPC Film

created a digital double of actress Sean Young

so she could reprise her role as Rachael

from the original "Blade Runner."

It may be the most convincing digital double yet.

To create the digital Rachael,

they 3D-scanned Young and aged her back

to how she looked in the original "Blade Runner."

Like with muscles and joints in "The Jungle Book,"

the most crucial CGI here is what you don't see: the skull.

To create a CGI skull, they combined the 3D scan

with a life cast done of Young

shortly after the original "Blade Runner."

Focusing on building this character's skull

allowed the artists to build the character's

de-aged features around it.

In addition, they focused on subtleties in Young's face

and even how makeup was done in the 1980s.

Actress Loren Peta doubled on set

before being replaced by the de-aged Young.

VFX supervisor John Nelson also said he team

closely studied the character's emotions

in the original "Blade Runner"

and incorporated them into the double,

helping to make real and fake almost indistinguishable.

Digital doubles got so realistic

that they would eventually allow Will Smith

to act alongside a younger version of himself,

while performing both parts, in 2019's "Gemini Man."

But creating digital doubles

won't cause actors to lose their jobs.

In Martin Scorsese's mobster epic, Robert De Niro,

Al Pacino, and Joe Pesci were de-aged

to play Frank Sheeran, Jimmy Hoffa,

and Russell Bufalino during various times in their lives.

There was no need for the actors to wear helmets,

tennis balls, or dots on their faces.

The tracking marks were invisible.

Scenes had to be captured with three cameras at once.

There was one central camera.

The two additional witness cameras were infrared,

which removed all the shadows from a given shot.

A new software called Flux revealed a lot more details

in the actors' faces, like how their faces are shaded

and the way the lighting hits them.

For additional reference,

the VFX team studied the cast's filmography.

This allowed the actors to focus on their performances

and the visual effects artists to focus on the de-aging.

But there are some things CGI still can't do,

like make an actor's movements look younger.

So a posture coach came to the set to make sure

the actors were moving appropriate

to the ages for a given scene.

Perhaps de-aging an actor's movements

is a CGI breakthrough for the 2020s.