A Splash of Mermaids for Fourth Pirates

ILM offers new techniques for mermaids and water in Pirates of the Caribbean: On Stranger Tides.

By Bill Desowitz | Tuesday, May 24, 2011 at 4:12 pm

Posted In | Magazines: VFXWorld | Site Categories: 3D, CG, Films, Visual Effects

Check out the Pirates of the Caribbean: On Stranger Tides trailers and clips at AWNtv!

The mermaids were enhanced by a new ILM facial system that decomposes expressions into individual shapes and a new application of Imocap. Images © Disney Enterprises Inc.

For Pirates of the Caribbean: On Stranger Tides, Industrial Light & Magic got to play in the water with mermaids, the Fountain of Youth and shrunken ships in bottles for 300 vfx shots. It was certainly a departure from the crustacean-like creatures and apocalyptic mayhem of the previous Pirates trilogy.

And for Ben Snow, ILM's visual effects supervisor, it was a nice change of pace from the hard surface challenges of the Iron Man franchise. The mermaids were especially different, appearing beautiful and human outside the water to entice and entrap the pirate victims and then menacing underwater with deadly fangs. But rather than going completely CG, they decided to apply a hybrid approach, in keeping with director Rob Marshall's glam aesthetic and desire to retain as much of the live-action performance as possible, particularly when it came to the hero mermaid, Syrena, played by Astrid Berges-Frisbey.

"The look of the mermaids was important," Snow says. "We conceived them as having an inner body that had all the scale texture on them and then an outer membrane that made them look human when they got out of the water. They evolved from being a little more human to a little more creature-like with vestigial gills, but we pulled back on that.

The fin was made more elegant by being proportionally larger than the actress' legs.

"It's a different performance capture challenge," he adds. "In this case, we had to take the scales and match them to the actual bodies and so it was a much more sheer transformation. We came up with new techniques and new tracking costume designs to help automate that: a nice smooth blend of an abdomen to a tail. Or put scales up on arms or faces. Briefly, you see transformations, so we had to match facial performances as well. So we came up with some facial tools."

According to Tim Harrington, ILM's animation supervisor, the facial capture was driven by two Mova Contour sessions: one to create the facial animation rig and another performance session of the actress watching previs or the shot (ADR style) on a monitor.