The Science Behind PIXAR

What is a model?

The digital model is a virtual wireframe of points and the edges that connect them. It defines the shape of a character. The wireframe model of Lotso below is a visual representation of what a digital model might look like.

What does a digital modeler do?

Character design starts with artists who create sketches and clay sculptures, called maquettes, to get each character just right. Then a digital modeler creates a virtual 3D model of the character, sometimes digitally scanning the maquette to use as a reference. Digital Modelers have to understand anatomy, as knowing where the bones and muscles sit affects the surface shape.

What is a rig?

Digital rigs are the virtual bones, joints, and muscles that allow models to move. It’s kind of like the strings on a marionette. A good rig has just the right amount of flexibility. Without the right controls, the animators can’t create the poses they need. Too much flexibility makes posing the model too time consuming.

What does a rigger do?

Riggers start with a virtual 3D model for a character. They study how a character needs to move based on the story. For example, Randall in Monsters, Inc. moves like a chameleon, but he also walks on two legs. Riggers break down those motions into individual elements and create the hundreds of control points that animators will use to create poses.

What is surface appearance?

A virtual 3D model is just a shape, the surface is how it appears. The way something looks is part of telling a story. You can tell Mater is an old car from his rusty brown surface and how his life is different from Lightning McQueen with his shiny red surface.

What does a surfacing artist do?

Surfacing artists construct each aspect of an object’s appearance using computer programs called shaders. They break down a complex appearance into specific elements. One shader may define Mater’s underlying brown color, another his rough texture, and yet another puts the gleam in his eyes.

What are sets?

Sets are the virtual environments in which stories take place. The setting of each scene conveys the context, story, and emotion.

What does a set designer do?

Set designers are architects. They build virtual environments from the ground up. Every pebble, tree, and building helps turn the storyboards into a believable world. Some set pieces are modeled individually the same way characters are. Other sets are created procedurally with computer programs.

What are cameras?

Cameras provide our view into the virtual 3D world. They frame each image to convey both where to look and how to feel about a scene.

What does a camera artist do?

Camera artists are cinematographers of the virtual world. They use virtual cameras to shape what is shown in each frame. Camera artists choose the composition, camera movement, and lens type to support the story.

What is an animation?

Animation is a series of images, each slightly different from the last, shown in sequence. When they are shown fast enough, we stop seeing the individual images and instead see an illusion of motion. There are many ways to create the individual images including hand drawings and photographs of objects. Pixar makes their images with virtual 3D models and sets.

What does an animator do?

Animators bring the story to life, posing characters to act out each scene. They start by breaking down an action into a series of poses called key frames that mark out important positions. Then, they use a computer program to describe how the object moves in between those key frames so that the resulting animation conveys the desired emotions.

What is simulation?

While animators focus on acting, simulation programmers create motion that makes scenes feel alive and believable. Some simulations –– hair, fur, and clothing–– respond to the way a character moves. Other simulations recreate natural phenomena, such as fire or water.

What does a simulation technical director do?

Simulation technical directors use computer programs to create effects and to move hair and clothing. Programmers start with a physics-based simulator, but then they fine tune it to balance believability with the artistic needs as well as the time it takes to compute the simulation.

What is lighting?

Lighting is an essential part of telling a story. Light shows you where to look and enhances the emotional feel of each scene. In Finding Nemo, the lighting also helped create the feeling of being underwater.

What does a lighting technical designer do?

Lighting designers light each scene to highlight the story and enhance the emotional impact. Pixar’s lighting designers have the additional task of defining virtual lights in the computer. They have to program in all of the individual effects of lighting such as where it casts shadows, how it reflects off shiny surfaces, and how is attenuates over distance in order to achieve the desired artistic effect.

What is rendering?

The virtual scene is set — the characters are shaded and posed, the lights and camera are in position, and the simulations are ready to run. But no one knows what it looks like until the rendering process turns all that data and programming into an image we can see by determining the color of each pixel in the image.

What does a rendering technical director do?

Rendering technical directors optimize the process of turning data into final 2D images. Scenes don’t always render perfectly the first time. Rendering TDs come in and try to figure out what went wrong.