Much of Digital Dimension's work involved head replacements
where Murphy's face, made up to look like Rasputia, was composited onto the
performance of a body double.
"Despite the fact that the effects in this film are
invisible, they are all extremely complex," explains Digital Dimension president Ben
Girard. "Because Norbit relied so
heavily on physical comedy, it was essential for our digital composites and CG to be
indistinguishable from anything shot practically."
The team preferred head replacement for many scenes,
including the water park sequence. Shots were filmed of a body double and then
Murphy performed the corresponding facial expressions in front of a green
screen, with his head made up to look like the Rasputia character. Elements were later composited.
For another scene, the body double's bright pink bikini
bottoms were made less obvious as part of a gag. Paint/roto supervisor Tammy
Sutton was able to hide the bikini until the reveal, using the grid warp tool
in Eyeon's Digital Fusion software, extending the character's belly over the
bathing suit.
"We were careful to stretch the entire belly evenly so it
wouldn't be a noticeable effect, and kept the natural movement intact by
mimicking the movement of the skin while she walks," Sutton explains.
For another water park scene, digital artist Brian DeMetz
created torrents of CG water to complete a composited shot simulating water bursting out of a chute as
Rasputia takes a ride down a water slide. Additional FX shots included placing
Murphy, as different characters, in the same scene as his Norbit character.
The most extensive use of 3D animation appears in a scene
where Norbit receives unexpected marital advice from neighborhood
dog Lloyd. A photo and video shoot with the dog allowed Digital Dimension's 3D team to record his range of motion and facial
expressions, and gather extensive texture references.
Digital artist Phi Tran
built Lloyd's head using 3DS Max based on Cyberscan data. Multi-angle HD footage
of the dog was recorded on-set to aid in tracking head movements. Flesh
simulation tools were used to add secondary jiggle to the pug's lips and jowls.