While real life twisters were rolling across the mid-west of the U.S. this spring, visual effects company Colorado FX in Santa Monica, California created its own mighty CG tornado with multiple composit elements for director Bob Newcomb of Boulevard Films and the client Husqvarna.
The :30 TWISTER was shot at North Carolina's Silver Hammer Studios on a greenscreen. Due to a limited budget, they had to use still photography for the opening and end shots, according to CG supervisor/digital artist Oliver Hotz. "We picked the photography before the shoot, and, while on the set, I was able to help the director with the farming of the shots by doing quick composits on my laptop." Hotz used Digital Fusion on the laptop and a Canon G2 digital camera, which was set up along alongside the camera. This way, the director would see how his framing as in relation to the stock footage plate.
Later on, Colorado FX painted out the existing trees from the stock photography and added moving CGI trees to enhance the stormy weather effect. Jerome Cheng cleaned up the original stock plate, then Hotz added the CG trees, using Maya, which were integrated and composited with the rolling sky stock footage plate by lead flame artist Paul Kirsh.
The CG tornado was created using Maya and LightWave. Hotz used The Beaver Project (www.thebeaverproject.com) to seamlessly integrate the packages and transfer particles and geometry, as well as animation from Maya into LightWave. The final elements were rendered in LightWave. The crew used a combination of SGI Octane, NT and Mac workstations.
Digital artists cleaned sis rhw xloaw-up tornado shots. "We rendered several layers for the finished result in order to get the necessary complexity needed for convincing atmospheric effects," said Hotz.
Kirsch composited the final shot in flame. Hotz said they were his team was happy with the result, claiming, "Usually these kind of effects jobs are handled by bigger companies that have a specific cloud pipeline and a team of dedicated particle-work artists."
Tony Zelzer was exec producer for Colorado FX, Tami Goldsmith was producer and Andrew Rocha served as digital I/O. Joe Murray edited the spot at Edit At Jones in North Carolina. Sound design was done by Ground Crew Studios.