Simulating Rapunzel's Hair in Disney's Tangled

How to read this

Category

Production talk / system breakdown: hair simulation

Contributions

• Simulating Rapunzel's 70 feet of hair with the proprietary mass-spring dynamicWires system using ~200 sparse guide curves
• Collision support structures plus on-the-fly spring forces on colliding segments to preserve hair volume and act as friction
• Art-direction controls: effortless dragging via reduced tangential ground friction, per-shot freezing of non-visible hair, and breakaway hair-hair constraints

Context

A production application of mass-spring hair dynamics, building on Selle et al.'s 'A Mass Spring Model for Hair Simulation'.Builds on: A Mass Spring Model for Hair Simulation

Correctness

Studio practice, not peer-reviewed; the approach is production-proven on Tangled, and the sparse-guide plus support-structure design is tuned to the extreme-length case rather than presented as a general validated model.

Clarity

Accessible; a first pass conveys the production challenges and the trick set, no heavy formulation to parse.

How to read it

Read once for the practical toolbox (guide-curve sparsity, volume-preserving forces, art-direction overrides); no second pass needed unless you want to cross-reference the underlying Selle mass-spring model.