# Lighting & Materials in 3D

**Track:** 3D, Shaders & AI Intuition — Creative Coding — the existing 50
**Framework / surface:** three.js
**Level:** Intermediate
**Prerequisites:** 3D Coordinate Space & Meshes, Color

**In one line:** In 3D you don't colour a shape — you light it.

## Theory, aesthetics & inspiration

A surface in three dimensions has no inherent color; it has a response to light. Shading models encode that response: Johann Heinrich Lambert's eighteenth-century Photometria established that a matte surface's brightness falls with the cosine of the angle to its light, while Bui Tuong Phong's 1973 model added the specular highlight that reads as gloss. Material and illumination are thus a single negotiation — roughness, metalness, and the placement of lamps decide what the eye receives. The aesthetic is chiaroscuro translated to arithmetic: form emerges from the gradient between lit and unlit, and a scene is composed less by painting objects than by directing the light that finds them.