Growth was one of the more challenging aspects, according to Lipowski. He animated black-and-white maps in After Effects and generated some low-res image sequences. Those growth images were read in by an expression in Maya, which drove feather scale and other properties (such as rotation for feather ruffling). Each feather had extra data associated with it, like UV position, which had been stored previously when rigged by the instancing mel scripts. Lipowski suggests it was a crude but effective feather system.

When it came to animation, the primary and secondary feathers were grown by hand by keyframing scale attributes and keyframing the wire deformers of the individual feather rigs, which allowed growth outwards (the barbs pop out of the rachises). Additionally, keyframes were set by hand every couple of frames to keep the wing from twisting (often around the elbows) and to minimize interpenetration. As the shot progressed, the matchmove often had to be tightened up with additional keyframes.

Lighting was done entirely with conventional Maya area and spot lights. They had enough images to generate HDRIs, but the lighting changes and large camera movement made it impossible for one or two HDRIs to cover the wild shifts in luminance. Lights were built based on the camera track and plate with numerous stage lights above and to the sides of Portman; six large chandeliers were approximated, several bright footlights near the orchestra were added and three very bright spot lights casting rim light were critical. Even with all these lights, the black levels in the plate changed dramatically due to the smoke in the theater (a volumetric effect lights alone could not approximate). A lot of color correction in comp had to be done as a result to make the wing feel integrated.

The shot was rendered in mental ray using the Rasterizer because of the huge amount of motion blur. Most of the wing is captured in one big beauty pass with an additional shadow pass and numerous mattes for the compositor.

Bill Desowitz is senior editor of AWN & VFXWorld.