Wojciech Zielinski of Mr. X describes the challenges of pulling off Amelia in the air as well as on water.
Toronto-based Mr. X provided CG aerial scenes and other vfx for the Amelia biopic starring Oscar-winner Hillary Swank and directed by Mira Nair (released by Fox Searchlight). VFX Supervisor Wojciech Zielinski led a team that handled 300 shots, including full CG aircraft (both in flight and on water), CG environments (include cloudscapes in the dawn and evening light, and dramatic flight scenes through storm clouds), crash landing a vintage plane, crowd duplication and set augmentation.
Mr. X built CG models of the Lockheed Vega and the Fokker Friendship using cyberscans of full-scale models built by the production's art department. These CG models were used for all of the CG aerial scenes in the film, both in the full CG environment sequences, and in daytime sequences, which use live-action shots for background plates.
The background plates for these shots were created using a real Cessna on location. The modern plane was then painted out and replaced with CG models of the Lockheed Vega and the Fokker FVII b Friendship, two of the aircraft flown by Earhart.
Not surprisingly, Nair requested seamless, naturalistic work.
"We were quite involved in pre-production and prevised three sequences, including the CG Vega flying across the Atlantic and the Friendship takeoff and landing and crash landing of the vintage airplane," Zielinski explained. "The biggest sequence is obviously the Vega flying through a cloudy environment. There were two big assets to solve: one was the vintage airplane and then obviously the environment. The cyberscan won't give you all of the detail, so there was a fair amount of work involved in finishing the asset. But it's great to have a real airplane as a reference. We also used it to acquire color texture for our CG assets.
"And then there was the cloud environment, which was the biggest challenge of this project. The whole process started with the previs and then we blocked each shot. The next step was to assemble a huge reference library, so our first pass was to see what we could find on the web but our results were not satisfactory. And it happened that during the course of the whole project that I was traveling a lot -- flying between Toronto and Nova Scotia and then we were shooting in South Africa -- so I had a camera with me all the time and every time I saw something interesting outside the airplane, I shot picture after picture.
"Then after previs was approved and Mira was happy with the sequence, we needed to block shots, so our first step was to bring polygonal clouds modeled in Maya into Houdini. Once we brought them into Houdini, we voxelized them and then procedural volume shaders were used to provide fine detail and those shaders allowed us to modify the density within each cloud. And the vfx team also handled lighting for the cloud and provided additional effects such as lightning and rain."
As for the clouds, they were rendered in Side Effects' Mantra using multiple passes and light layers. The biggest challenge was rendering, according to Zielinski. "It was totally killing us, so we had to optimize our preview techniques in order to get visual feedback during every step of the process."
The key for the CG planes, meanwhile, was lighting. Mr. X's pipeline includes image-based lighting. They took HDRI images that were used to illuminate the airplanes. And in some of the sequence they had some interactive lighting: for example, when Vega flies through the storm. These were rendered in RenderMan.
For the CG water in sequences when Amelia flies the Cessna, they had to show believable interaction between aircraft and water. "So we had to proceed with a semi-practical solution," Zielinski adds. "We had a model airplane that flew for our hero plane and later on in the process we painted out the model." Shooting the scenes with the Cessna provided the basic water interaction for the final shots, which was augmented with CG water splashes and spray.
"Because of our expertise in CG technologies, we know what can be done, both technically, and in terms of the budget," Zielinski concludes. "This way we can help the director extend her creative vision through well-placed visual effects. It works because we approach the work the same way they do -- as filmmakers."
Bill Desowitz is senior editor of AWN & VFXWorld.