This is a shot from Netflix's "Over the Moon"
while the film was still in production
as Fei Fei and her pet bunny, Bungee, fly to the moon.
And here's the final version you see in the film.
You'll notice that Fei Fei's skin
now looks more like human skin
and the lights from her control pad
properly reflect off her helmet,
making the shield appear more like glass.
The one ingredient responsible for this transformation?
Lighting. But lighting 3D-animated movies
isn't only about the decisions
that make scenes look more realistic.
It's also about the emotional choices
that turn this image into something magical.
Fei Fei: I did it! I did it!
Narrator: So, how exactly does lighting in animation work?
And, warning, spoilers ahead for "Over the Moon."
Lighting is one of the final elements added in 3D animation,
but animators have to think about it early on.
A lighting artist's decisions are guided
by blueprints called color scripts,
which come before anything is animated.
These are hand-painted pictures
that break down an animated film scene by scene.
By viewing them all next to each other,
the director and production designer
can break down the emotional story arc.
And lighting here is key.
Celine Desrumaux: I'm trying to see in the big story.
Which is the lowest point? Like, the saddest moment?
Which is a more action moment?
Which is a more funny moment
or the most extravagant moment?
Narrator: That's Celine Desrumaux,
the production designer for "Over the Moon."
Celine used color scripts to decide
how they'd create a contrast
between Earth and the moon kingdom of Lunaria.
She found that by making the colors on Earth less saturated,
the colors of Lunaria, with all of its
light-emitting structures and characters,
would look even bolder.
Later on, the color scripts get redefined into a color key,
which tells the lighting team
how light or dark a given scene or shot should be
while also identifying the exact number
of lights, light sources, colors,
and even how much shadow your subject is casting.
All of this information is necessary for Clara Chan,
a CG supervisor who led the lighting team
at Sony Pictures Imageworks for "Over the Moon."
Clara Chan: Pretty much we control the intensity,
the placement of the lights, the colors.
Narrator: While lighting in live-action movies
illuminates what's already physically there on screen,
lighting animated movies works a bit differently.
Without it, the physical appearance
of what we see on screen is completely altered
and won't look as realistic.
This happens in a few different ways.
First is a process called surfacing,
which determines an object's texture
and how an object will appear once light hits it.
Things like roughness and shine
are decided through surfacing.
To put it simply, surfacing artists will assign
numerical values to something like Fei Fei's jacket,
perhaps a high value for reflectiveness
and a low value for, say, roughness,
but we won't be able to see
what those values do to the surface
until lighting artists actually add the light.
To see just how surfacing works to make a scene more real,
let's take a closer look at the characters' skin.
Before the lighting is added in this shot,
Fei Fei and Chin's skin looks opaque.
Once bright yellow light is added,
the shot not only becomes much more colorful,
but their skin is also taking in
some of that color and light.
Chan: Human skin is translucent,
and when light gets in, it bounces around inside,
so you get this glowiness.
Narrator: The subtle glow throughout the skin
makes it look like real skin instead of plastic.
But making an animated surface look good
also requires figuring out how light behaves in real life.
Animators place many lights by hand,
but there can be so much light in a given shot
that computers need to lend a helping hand.
3D animators do this using ray tracing,
a rendering method that requires a lot of computing power
in which the virtual camera shoots out a light-sensing ray
until it hits an object in the scene.
If the object is transparent,
the light will travel through it.
And if the object is reflective,
the light will bounce off at an angle.
They can also use the more advanced path tracing,
which sends out multiple rays at once.
As you can see, instead of going right to the light source,
the rays bounce around the room,
hitting every possible angle
until they locate the light source.
As the light bounces around during path tracing,
subtle shadows and reflections are produced.
Take a look at this shot from "Incredibles 2,"
which takes place in a school hallway,
so the primary light sources
are these overhead fluorescent lights.
The rays bouncing around the scene
determine the shadows cast by these background characters,
the shadow of Violet's hair on her shoulders,
and even the reflection seen on this clock behind Tony.
Path tracing is why newer animated films look so real
compared to older animations,
which didn't have the processing power we do today.
It gets more complicated when characters and objects
are lit by multiple light sources,
like the scenes where Fei Fei and her extended family
celebrate the Mid-Autumn Festival.
Here, there's some light coming from
the kitchen behind them,
but mainly from the lanterns above their head.
That means the computer has to chart the path
of each ray of light coming from each light source
that makes it to the camera's lens.
Chan: There is the moonlight also in there,
but in a lesser intensity
so we could feel the actual lanterns hanging above them.
Narrator: As Fei Fei goes inside,
you can see her bangs cast shadows.
The computer calculated that the shadow of her bangs
could cover a lot of her eyes,
so the lighting team made the decision
to break the rules of reality
and eliminate or lighten them when necessary
to help the audience better see her facial expressions.
But it's not just up to computers to make light look real.
Lighting artists need to study how light acts in reality
by observing the real thing,
like that in order to see the surface of water,
you need a reflection.
This is exactly what Pixar did
when creating the underwater world of "Finding Nemo."
According to Pixar director of photography
Danielle Feinberg, the team took
a real clip of underwater footage,
recreated it in the computer to break it down,
and found its most prominent feature was light.
It impacts everything, from visibility to color.
They found that objects lose their full color
as they travel further into the water.
Meanwhile, these light beams help guide the eye,
showing the viewer which way is up
in shots where the surface is invisible.
But through rendering, these subtle light features,
known as caustics, showed up on the ocean floor.
It's one of the many ways light
realistically reacts to water in the movie.
But lighting's purpose isn't just about
physically improving the look of an animated project.
It also helps set the mood and emotional arc
established by the color scripts.
While "Finding Nemo" created nearly photorealistic water,
it also defied those same rules
to make a scene more emotional.
Danielle found that one of the lighting elements
they had the most leeway with was color.
So while the water in Sydney Harbor is actually turquoise,
the lighting artists instead made the water mucky and green
to represent one of the film's emotional low points.
In that "Incredibles 2" hallway shot,
they weren't just looking
at how light realistically behaves.
According to Pixar lighting artist Charu Clark,
the fluorescent lights created
a sterile and uncomfortable feeling,
which mirrored how Violet felt at the moment
her crush couldn't remember who she was.
Later in the movie when Tony finally remembers Violet,
the same location is lit up with bright sunlight
to evoke a happy ending and the two characters' fresh start.
Different lighting for a different mood.
Meanwhile, when Fei Fei and Chin first arrived on Lunaria,
it wasn't just about making
their skin and outfits stand out more.
The filmmakers wanted to create a sense of awe
and an overwhelming feeling of wonder for the audience.
So they filled this shot with bright, glowing yellow light
emitted from the structure around them.
Desrumaux: I wanted to, like, keep a space
for the audience to be amazed
for when they're going to the moon.
Narrator: And during those family dinners,
especially the one after Fei Fei returns from Lunaria,
they wanted to create a warm and festive mood.
So even though there's light from the moon and the kitchen,
the lighting artists chose
to amplify the light from the lanterns
to set the right emotion for the scene.