One of Us and Milk VFX brave the elements in their work on Baltasar Kormakur’s action adventure.
When assembling the team to digitally recreate the fatal 1996 Mount Everest expedition where eight mountain climbers were killed during a massive blizzard, overall visual effects supervisor Dadi Einarsson (The Deep) sought the expertise of U.K. companies One of Us and Milk VFX.
“Everest presented us with some unique challenges, for sure,” observes One of Us visual effects supervisor Dominic Parker, who along with colleague Emmanuel Pichereau was responsible for over 70 VFX shots, including set extensions, digital matte paintings of the summit and six establishing storm shots. Says Parker, “If nothing else, the simple crystal clarity of vision on the summit of Everest allows no hiding places. Add to this the fact that the light there is somewhat surreal, with the sky a deeper shade than one can imagine, and the atmosphere suffused with crystalline particles which ping in the sunlight. It’s a tough sell.”
Working with Einarsson was a smooth experience. “As with many of the best projects, the supervisor approached us in a spirit of cooperative creativity,” Parker remarks. “The collaboration meant that once our shots developed, he responded. Of course, a lot of reference footage underpinned all discussion, and a few amazing moments of GoPro on the summit became our touchstone.” Parker adds, “The weird thing was that somehow most stills don’t do it justice. It was the crappy quality GoPro HD which really had us with our hearts in our mouths.”
“Our first involvement in the project involved concept and tests, pretty early on,” notes Parker. “I believe they were successful, and helped to give the project some momentum. And then, for some reason, we found we were not on the project…at least not until some six months later.” Previs and postvis were not a factor. “We took turnover too late to be involved in previs or postvis. We were straight into temps. But the live-action and built set determined what the action would be,” Parker continues. Other tools aided the process. “We had digital models of the mountain and the whole range, as well as the necessary HDRIs.”
“We had a couple of distant digital doubles, but mostly the required characters were in shot,” states Parker. “Once you leave the summit you are soon over the brow of the first ridge.” Not everything was digital effects. “We had some practical effects and an awful lot of CG. It’s almost impossible to shoot a library of practical elements to cover such a range of shots. Angles and obstacles vary, and the sheer quantity of stuff you need in frame is huge,” Parker explained.
“The issues with this project were the usual mixture of the practical/technical and the creative,” adds Parker. “As is usually the case, the creative issues are the more interesting and harder ones to talk about. The issues of rigging, compositing and rendering were not the challenge with Everest. If there was one out of the ordinary factor, it was the sheer amount of prep work required. The Summit Sequence was shot on a greenscreen stage, without any constraint on angles or moves. Dadi did what was possible in terms of greenscreen, but he was also wise enough not to let tidy seams get in the way of the action. Let us say that some of the greenscreens could have been more…complete.”
“The biggest challenge was to find the look,” observes Parker. “That took into account the stunning clarity, the icy sharpness of the air, the deep blue of the sky, the almost infinite view, and the level of exposure which accommodates skin tones and blinding white snow. All of these things had to be balanced to produce an image which held together, and this was a complicated process with much trial and error, and back and forth with the supervisor and director [Baltasar Kormakur].”
Digital assets were shared with other visual effects vendors. “As with most projects nowadays, there was some sharing of assets, and of course there was also the bag and tag stereo delivery at the end of post, the ultimate asset share,” Parker concludes, “A big thanks to fellow supervisor Emmanuel Pichereau, and to the whole Everest team at One of Us.”
Adding to the Everest’s sense of realism was Milk VFX, led by visual effects supervisor Murray Barber, who was responsible for creating 15 icy breath effects shots for the film.
According to Barber, “The Milk team chose to approach the icy breath effect as a dynamic 3D task rather than using 2D elements due to the type of head movement and wind interaction.”
“A non-deforming model was tracked to each actor's face and used for the basis of our smoke simulations,” Barber continues. “Using this geometry we were able to create a simple ‘mouth box’ that looked a little like an empty tissue box, and a noisy emission volume within it. This initial density was pushed forward in sync with the actors' exhalations and, as it collided with the walls of the ‘mouth’ and was forced through a smaller opening, emerged with suitable turbulence and flowing qualities.”
“Due to the level of background noise in the audio track [wind blowing/tent flapping], we chose to key the emission of breath by hand,” explains Barber. “In fact, this ended up giving us more creative control of how and when breath was emitted and allowed us to exaggerate interesting light interactions in the occasional shot [e.g. with the head torch]. Throughout the sequence we found that the greatest challenge was maintaining a fast, light look to the breath without destroying the natural turbulence patterns. There was no magical method of solving this other than just careful dialling in of the simulation on a per shot basis.”
Trevor Hogg is a freelance video editor and writer best known for composing in-depth filmmaker and movie profiles for sites such as the CGSociety, 3DTotal, Live for Films and Flickering Myth; he is a big fan of Raiders of the Lost Ark, Batman: The Animated Series, The Hobbit, Studio Ghibli, and Peter Weir.