Research group releases paper detailing a new way to art direct hair animation and provide greater artistic control.
Hair remains one of the most difficult, yet critical, character elements to animate in CG – for Disney, from Rapunzel to Elsa to Moana, artists have bravely tackled the Herculean task of animating some of the studio’s most iconic and complicated hair, moving each strand by hand or with various pipeline tools at their disposal. However, based upon the work of a group of Disney computer scientists, with help from artists at Walt Disney Animation Studios, Disney animators may soon suffer through fewer bad hair days on their animated feature film productions.
In a paper presented last week at the 17th annual ACM SIGGRAPH/Eurographics Symposium on Computer Animation and published in the Computer Graphics Forum journal, four Disney Research members have developed a new method of simulating hair that provides a previously unavailable level of artistic control.
Published under the title “HairControl: A Tracking Solution for Directable Hair Simulation,” the research began with the premise that associated character elements such as flesh, clothing and hair are every bit as important to a performance as the primary character actions – authors Antoine Milliez, Robert W. Sumner, Markus Gross, and Bernhard Thomaszewski have been working to find new ways to simulate hair in a physically plausible way that can still be art directed to capture the animator’s stylistic intent.
Their work concludes that HairControl, which represents a constrained method specifically designed for guiding and styling the coarse level motion of hair simulation, provides a much greater level of art directed-control than existing methods, which rely on consistent geometry (cloth, solids) for the simulation medium, or particles (fluids) which provide no specific structure. Using a few sets of artist-controlled guide hairs, an animator can create a realistically plausible hair simulation. These guide hairs, in essence, pull the bulk of the simulated hair along, providing animators with a better understanding of how a character’s hair will fling around.
Dan Sarto is Publisher and Editor-in-Chief of Animation World Network.