# Procedural Vertex Deformation

**Track:** Advanced 3D — Advanced Creative Coding — proposed (50)
**Framework / surface:** three.js
**Level:** Hard
**Prerequisites:** Custom BufferGeometry From Scratch, Noise in Shaders → FBM

**In one line:** Displace geometry in the vertex stage via noise (terrain, wind).

## Theory, aesthetics & inspiration

Geometry need not be static: the vertex shader can displace every point before projection, sampling a noise field to push vertices along their normals. Layered fractional Brownian motion over a plane produces rolling terrain whose silhouette and shading emerge entirely on the GPU; a time-shifted noise added to foliage or cloth yields wind. The subtlety is that moving positions invalidates the original normals, so lighting requires recomputing them—analytically from the field's gradient or by finite differences across neighboring samples—lest a deformed surface shade as if flat. Built on Ken Perlin's gradient noise, the aesthetic is living landscape and breathing matter, animated procedurally rather than keyframed.