New wrinkles: a novel technique for animating leather helps get Daredevil dressed to thrill. (CG Superheroes).

Of all the digital superheroes dazzling movie-goers this year, none had to appear more "human" than Daredevil. That's because the title character of this summer's action film acquired his powers less from the assimilation of non-human abilities and more from the hyper-compensation of his remaining four human senses, after a childhood accident robbed the young Matt Murdoch of his sight.

With behind-the-scenes help from the effects group at Rhythm & Hues Studios, director Mark Steven Johnson achieved that goal, resulting in film critic Roger Ebert praising the digital double for transcending the look of an animated character and appearing more real and convincing than its contemporaries. Key to making the digital Daredevil look as human as possible were new character-animation techniques developed by Rhythm & Hues that realistically simulate the wrinkling of "tight" fabric. The procedural method, involving automatically generated displacement maps, was designed to replicate the unique creasing properties of the hero's crimson leather costume, which, unlike spandex, stretches and folds unpredictably with the extreme torsion flora the hero's gymnastic style of locomotion.

Daring Displacements

Using a digital scan of actor Ben Affleck in full Daredevil regalia, the Rhythm & Hues artists obtained a high-resolution polygonal mesh, along with complete texture information of the leather outfit, which they imported into Side Effects Software's Houdini and Rhythm & Hues's proprietary Voodoo animation system. The group also assembled a library of reference material, including footage of a stuntman performing exaggerated motions that demonstrated the intricacies of the leather's deformation under the stresses of acrobatic movements.

To create an animatable model without losing the detail of the scanned data, the group worked on two separate Daredevil models at the same time. The first, containing the high-density polygonal mesh, was used only for texture mapping; the second, a less-dense version of the first, was fully rigged and used solely for animation. The team also created several versions of the animation model in different resolutions, incorporating both polygonal and subdivision surfaces, to meet the detail requirements of various shots.

Prior to rendering, the artists had to restore the details of the initial model to the animation model by integrating three levels of displacement maps. For the first layer, the team developed a tool for determining the differences between corresponding points across the two versions within a series of maps, which the group then applied while rendering the animation model, The second level added the texture, grain, and stitching of the leather costume using high-resolution displacement surfaces that were hand-painted in Right Hemisphere's Deep Paint 3D and confined to select regions of the suit. This afforded a level of realism without massive amounts of surface data.

The actual wrinkling of the suit was accomplished in the third level using a Voodoo script that captured the squash and stretch transformations of every polygon in the texture map for each frame. The group then created a tool for use in its proprietary compositing software, Icy, that automatically integrated a hand-painted, animated wrinkle map corresponding to each polygon's "squash and stretch" map.