Capturing the Complexity of Hair Motion
and Pierre Poulin
GMOD, 64(1), January 2002
Modelling the highly inelastic interactions
inside hair, and between the hair and the
character body is a determinant feature for
achieving realistic hair animation. However,
the extremely large number of hair strands
has so far prevented animators from handling
these interactions. It is also unclear if
they should be treated at the level of
individual hair strands.
This paper proposes an approach to handle
these interactions, based on a new clustering
paradigm. The high friction forces between
neighboring hair strands, yielding a high
motion coherence, is simulated by clustering
these strands into an anisotropic viscous
volume representing a hair wisp. All other
interactions between hair strands are
approximated at the wisp level, thanks to an
anisotropic behavior that allows pairs of
wisps to interpenetrate or to collide
depending on their relative orientations.
The wisps also offer the necessary structure
to efficiently simulate the collisions with
the character body. The model results in
visually-realistic animations, where
complex wisp interactions capture both
continuities and discontinuities easily
observed in thick, long hair.
Hair, collision detection and response, layered-models, physically-based animation, natural phenomena.
title = "Capturing the Complexity of Hair Motion",
author = "Eric Plante, Marie-Paule Cani, and Pierre Poulin",
booktitle = "Graphical Models",
year = "2002",
volume = "64",
number = "1",
month = "January",
pages = "40-58"
Postscript gzipped earlier version of the
Simple animations to illustrate the effects of viscosity
Viscosity of 0.5 movie vs. viscosity of 50.0 movie.
Simple animations to illustrate the effects of collision vs. interpenetration
No interactions movie;
Collision only movie;
Interpenetration only movie;
Collision and interpenetration movie.
Complex hair animation from a tracking session
Similar motion than original tracking session movie.
Short hair animation sequence movie.
Medium hair animation sequence movie.
Long hair animation sequence movie.