Curly-Cue: modeling Afro-textured hair in 3D

Curly-Cue: Geometric Methods For Highly Coiled Hair is the first paper about Afro-textured hair ever to be presented at a SIGGRAPH conference in all its 50-year history, writes Theodore Kim, one of its authors.

"When you STOP assuming straight hair is a universal baseline, lots of new science opens up," Kim wrote. "We identify three geometric phenomena unique to highly coiled hair: phase locking, switchbacks, and period skipping. These phenomena do NOT appear in straight hair, and thus have been ignored at SIGGRAPH, and CGI in general, for half a century."

The other co-authors are Haomiao Wu, Alvin Shi and A.M. Darke. The abstract.

We present geometric methods for generating shapes that are characteristic of highly coiled hair. Different features become visually relevant when hairs are well-approximated by high-frequency helices instead of low-frequency curves, so we present algorithms for three such phenomena. First, a Fourier-based method for phase locking, the process by which disparate helices near the scalp coalesce into a single curl. Second, a method for period skipping which models individual helices deviating from the coalesced curl. Third, a non-linear optimization that directly generates the shapes of switchbacks, a.k.a.~helical perversions, which heretofore could only be produced through direct physical simulation. By applying all three methods in tandem, we show that we can achieve richly detailed depictions of highly coiled hair.

The paper is published at Yale University's website and source code provided. And here's video: