Many methods have modeled single elastic rods based on Cosserat theory [Pai 2002;Gr´egoire and Sch¨omer 2006]. Bertails etal. [2006] extended the Kirchhoff model to hair, modeling curlswith a piecewise helical structure. This model contains an implicit centerline, but subsequent methods were developed with explicit centerlines for Cosserat [Spillmann and Teschner 2007] and Kirchhoff [Bergou et al. 2008; Bergou et al. 2010] models. These rod methods define material coordinate frames along the hair curve.Because we have an explicit hair representation without a predefined frame at each segment, our method parallel transports the natural Bishop frame directly, similar to the reference frame used in [Bergou et al. 2008]. However, we compute this frame along a smoothed representation of the hair curve instead of the curve itself, reducing the sensitivity of the frame to changes in hair positions.