• Blogs
• Forums
• Tradeshows
• Partners
• White Papers
• Events

Ocean Spray: A Tidal Wave Rocks New York in Deep Impact

Jun 1, 1998 12:00 PM, Ellen Wolff

For the new DreamWorks release Deep Impact, the visual effects team at Industrial Light + Magic was required to sell audiences the Brooklyn Bridge-or at least a convincing impression of it. In a climactic scene in Mimi Leder's latest directorial effort, a 1,000-foot-tall wall of water, traveling 200 mph, destroys several Manhattan landmarks with tons of foam and spray.

While the film is actually more story-driven than effects-driven, according to ILM's Oscar-winning visual effects supervisor Scott Farrar, "the effects shots they do have are really big!"

One shot in this sequence featured the wave taking out the Brooklyn Bridge, and then moving off into the distance, breaking up the skyline with gigantic bursts of water. In preparing for the shot, Farrar recalls, "we studied destruction movies and lots of films showing atomic explosions. What's really hard about this stuff is that you have to be ever vigilant that you're not making something up that reads false to the eye."

The aerial shot of New York chosen as the background plate was a chopper flyby overseen by Farrar himself. After completing all the 'hover shots' depicted in the storyboards, Farrar used his last 100 feet of film to grab a more dramatic view. "I thought, let's just fly by the bridges, 'cause that's always really kinetic. Of course that became this shot."

Back at ILM, he explains, "we then put in a plastic shader, as we call it, which is a really rough shape of a wave-just a big green wedge that would be animated to slide along at a complementary angle to the camera and the flight line of the helicopter. The tricky part was that the bridge was at an angle to the camera, and we wanted to have a closing distance where we would feel the wave engulfing the bridge, overtaking the speed of our helicopter. The wave is moving towards the camera through the whole shot, so we've got several vectors happening." Along with the CG wave, notes Farrar, "everything was completely built in the computer-the bridge, the buildings, the cars and the debris." The modeling software used was Alias.

The next step was to take the real bridge out of the plate and replace it with the CG model. The question Farrar faced was "into how many pieces should it break apart? We tried different things. In one, the cables were broken at one end; the whole thing whipped out of the way or got pushed by the wave. But that looked too rubbery. The bridge, because it's so heavy, simply can't be displaced that quickly. So we finally went to an effect where the pieces get laterally thrown out of the frame like piano keys being blown apart. Meanwhile, the cables that are broken have kind of a whipped motion to them." This look was achieved using Softimage and ILM's proprietary code.

"Once that animation seemed right," Farrar recalls, "the next task was to put lots and lots of blasting mist around the parts that were breaking, and at the intersection of the wave against the water. Otherwise it's just a flat plane intersecting the bridge." Using Wavefront Dynamation particle system software,the ILM team wrapped the surfaces continuously with emitting particles to represent foam. Farrar notes that lead TD David Horsley "did an amazing job-he plumbed the depths of particle behavior regarding puff-ball foam!"

Farrar likens particle system procedures to "setting up lawn sprinklers-you decide when they'll turn on, how big they'll be, how long they'll run, how far they'll fly and what their vectors will be. You turn it on and run it overnight, but you never know what it will look like exactly-sort of like leaving your house and lawn for six months and hoping you haven't missed a spot!" He stresses that along with the more automated work, "this show reflects incredibly intensive hand-done work. We had 'swat teams' of roto and paint people descend on each shot, because without them you can't make this work."

"Finally, the sky had to be replaced," notes Farrar, who had filmed the original background plate on a sunny day. "We needed a dark, moody, threatening sky. That was pretty well concocted using lots and lots of still photos to create multidimensional, moving clouds. My philosophy is to import from photos if possible because they automatically give you complex colors, details and grain. We also had to apply moving grain." The image processing of the sky was done on a Flame and the final image was rendered using RenderMan.

When all was said and done, this sequence in Deep Impact had water shots containing several million particles, even more than was required for ILM's work on Twister. Despite the huge size of the studio's computer power, Farrar reveals that at one point in this show "we used every processor we have!"

Mimi Leder, director; Scott Farrar, visual effects supervisor; Denise Ream, visual effects producer; Ben Snow and Michael Bauer, CG supervisors; David Horsley and Hayden Landis, technical directors; Rita Zimmerman, Sabre Artist (Flame); Philip Alexy and Jason Ivimey, animators

© 2009 Penton Media, Inc.