How does 3D animation work?

Toy Story's 114,240 frames took about 800,000 computer-hours to render. A 3D character is a hollow skin of vertices, edges and faces. Modellers start from a cube, cut it into quads, push and pull it into shape, then subdivision smooths the cage: 384 faces become 24,576.

Read how it works: How does 3D animation work? · The history of 3D animation · More boxes on Glassbox

Chapters in this interactive model

1. Modelling: from a cube to a head: Points, edges and flat faces, pushed into shape and smoothed by subdivision.
2. Rigging: bones, skin and controls: A skeleton inside the mesh, skin weights that glue them together, and handles an animator can grab.
3. Animation: keys, curves and timing: Pose the rig at a few key frames; the computer draws the in-betweens along curves you can shape.
4. Texturing and shading: Unfold the skin flat, paint it, and choose what it is made of.
5. Simulation: cloth, hair, rigid bodies and particles: Some motion is too complex to key by hand, so the computer works it out with physics.
6. The pipeline: from layout to final frame: Six departments hand one shot down the line, and a render farm does the heavy lifting.