# Soft Bodies (Pressure Model)

**Track:** Simulation & Complexity — Advanced Creative Coding — proposed (50)
**Framework / surface:** p5.js
**Level:** Hard
**Prerequisites:** Spring-Mass Meshes & Cloth

**In one line:** A closed Verlet shell with internal pressure for jelly physics.

## Theory, aesthetics & inspiration

A soft body is a closed Verlet shell — a ring or hull of point masses held by distance constraints — inflated from within. Pressure follows the ideal gas law: force scales inversely with the enclosed area or volume and pushes outward along each edge's normal, so a dented balloon springs back as compression raises internal pressure. Maciej Matyka and Mark Ollila described this approach in their early-2000s pressure soft-body papers, building on the mass-spring tradition. The motion is unmistakably jelly: wobble, squash, and recovery, a membrane that dimples on impact then rebounds, holding its volume like something alive and faintly buoyant.