Rising Sun created a different set of claws for the dramatic scene in which they first appear on young Logan. Most of the plates were shot with the actor wearing practical bone claws built by Amalgamated Dynamics. "The intention was originally to keep the practical claws in-shot, but the design was changed throughout, and there eventually became continuity issues that needed to be resolved through CG. We were provided with assets and turntables from other vendors to assist in this process, in addition to receiving the prosthetic for reference. The main thing was to ensure that the look was correct with regards to the continuity of the film, and the other vendors. Although we ended up removing the prosthetic claws, they did provide a perfect reference for tracking, animation and placement."

The appearance of the juvenile bone claws on Young Logan required a specific interactive effect. As the blades slowly emerge, the skin on the back of the hand starts rising and moving. The team rendered a series of 3D passes and applied the warp in 2D. "We also went through some iterations where the skin would peel back as the blades come out, but that was deemed to 'gory' for the rating," Proctor says. "In the end, you can see the bones traveling under the skin, but it's fairly clean for the exit of the blades. We don't see any blood. The ratings really drove that look -- it needed to be creepy, but not gruesome."

The majority of work was created using a Maya/3Delight/Nuke or Shake software pipeline, with additional work being carried out in Houdini associated with Mantra.

Cinesite created this plane sequence completely from scratch… without the help of adamantium claws.

Mutant and Airplanes
Other mutant effects were handled by Soho VFX, Toronto, where Allan Magled served as vfx supervisor and Keith Sellers as digital FX supervisor. A crew of 50, including artists and support, spent over 16,000 hours on the project, working on more than 230 shots. Part of the work focused on Wolverine's claws (bone and adamantium), but the team also provided CG augmentations and/or effects for Creed, Deadpool, Gambit and Wade.

Meanwhile, Cinesite, London, was involved in creating a series of shots featuring an entirely CG plane, clouds, ground and sky. VFX Supervisor Jon Neill and VFX Producer Ken Dailey oversaw the project that was completed in just five weeks. The plane was modeled from scratch using Maya, and included navigation lights, landing lights (with interactive glow to the surrounding clouds), vapor trails engine glow, and heat haze. The surfaces were rendered via standard in house metal shaders rendered through RenderMan.

The clouds were generated by designing geometry in Maya, and then running it through a custom Houdini volumetric cloud system, which was rendered through Mantra. "The clouds were shaped as volumes filled with metaballs in Houdini," Neill notes. "Each metaball has a density attribute to control the opacity, and so get a nice wispy layer above the clouds. These metaballs were rendered in Mantra with a volumetric shader and a 3D fractal displacement shader to add noise and details. The volumetric shader makes a nice fade when going through the clouds."

For the spectacular "Powers of 10" shot that ends the film, production turned to Matte World Digital. President and VFX Supervisor Craig Barron took inspiration from the famous Powers of 10 short from Charles & Ray Eames. "Starting on Logan, the camera rises up thousands of feet revealing all of the Three Mile Island aftermath, and finally into the clouds. Matte Painter Eric Hamel made five 3D matte paintings to create the illusion of a continuous pullback. The biggest matte painting was being 16k wide for the terrain elements. Luis Hernandez, Morgan Trotter and Glenn Cotter made additional 3D elements, including arriving fire engines, military vehicles and police cars. To complete the shot, Geeta Basantani composited in many drifting smoke and fires elements that were tracked into the shot including a digital double for Wolverine."

Last Minute Challenges
In some ways, the whole Wolverine production process was a slight learning curve for Hood as to what was possible in terms of the visual effects. "It's commonplace to both underestimate as well as overestimate the challenges involved, as well as the scope of the work for any given shot," Lyn concludes. "Just about every director in the world asks for the moon, and it's the job of vfx to try to deliver. On this movie, the main challenge probably was establishing the look of specific sequences very late in the project cycle. That was particularly true for the cooling tower fight, as well as the post tower collapse. These were two very extensive greenscreen shoots -- and the two scenes were the last in the schedule to complete."

Alain Bielik is the founder and editor of renowned effects magazine S.F.X, published in France since 1991. He also contributes to various French publications, both print and online, and occasionally to Cinefex. In 2004, he organized a major special effects exhibition at the Musée International de la Miniature in Lyon, France.