Issue link: http://digital.copcomm.com/i/585189
THE MARTIAN www.postmagazine.com 20 POST OCTOBER 2015 fiction film. But [it's] a huge undertaking to build that in enough detail so we can see a lot of those details in close ups in some of our final shots." MPC needed to enhance the surfaces of the actual footage you shot, correct? "Yes, absolutely. Jordan is a beautiful set- ting and had really nice colors for Mars, ranges of reds and yellows for sand, and beautiful mountains. Unfortunately, everything is covered in tuffs of grass everywhere, there are these bushes that no matter where you go in the entire landscape, you can't find five square me- ters of dessert that doesn't have some tumbleweed grass growing somewhere. So, that was one of our biggest tasks. And the other part was the sky. So, whilst we were able to shoot these beauti- ful landscapes, we ended up having to replace much of the ground with a cleaned-up version of itself. In addition, we would add rocks, craters and features like that just to make it look more Martian in terms of what people would expect to see and what we've gained from references from NASA missions to Mars — they have photographs — so we were able to reference a lot of that. "We also utilized those images to figure, well, 'What color is the sky on Mars?' Everybody has a slightly different opinion of it, depending on which photo they see — there are so many different images that NASA and the European Space Agency have created over the years of Mars and they're very inconsistent. As it is on Earth, it's not always a blue sky but Mars seems to range from anything to pale yellow, grey, and sometimes a big pinkish or a bit of green. So we utilized a lot of the reference images of Mars to try and balance into one universal color temperature that we could use as a guide for what we did to our shots of Earth. Naturally, we had a strong blue sky, so one of our questions was, 'What color do we need to correct that to and how do we go about doing it where we give Ridley a good starting point for him to do further grading when he gets into the final DI stage once the film is conformed?' We basically came to the conclusion that the sky needs to be almost grey with a hint of greenish yellow to it. "Also, Ridley's touch to this is to allow a certain style of clouds to Mars which sort of feels like a bit of a creative leap, as Mars does have clouds but not water-va- por clouds like we expect but ice crystal clouds which form from the CO2 ice. Also, there's large amount of dust present in the Mars atmosphere, which gives it a sort of yellowish color. We took a little artistic license from Ridley's direction to create some of these clouds. We made them sort of browns and reds to make it like there are streams of dust caught in high altitude winds blowing across the surface of Mars, which is not completely out of the ordinary, but I think the way we treat- ed it was probably a little more romantic than what it would really be if they were there on the surface of Mars. "Ridley's direction for us on that was based on something he shot elements for on a commercial he worked on maybe 20 years ago. He had fast-moving clouds in the sky made up of sea spray blowing off white cap waves and a very strong wind. And these very interesting textures of strands of white water being blown off the top of waves and he used that upside down, as a sky texture, and he told us to look at that as sort of a source of reference. We ended up using these fast-moving streaks of fine tex- tured clouds that had really nice internal movement. Definitely helped the look of the movie. It's really stunning." What were some of the key tools you used? "Nuke is pretty much a main stay com- positing tool of any large VFX vendor. Outside of that, we went through the match-move process to lock down our camera movements to match the live action plates, so usually 3D Equalizer is most people's preferred match-mover choice these days. Our CG animation is pretty much based in Maya, and the same for modeling. For rendering, I be- lieve it depends on each vendor. I believe Framestore used Arnold as their renderer and MPC used Renderman." Can you talk a little about the color correction? "MPC's compositing team came up with a really nice custom-made filter, which we called 'Earth to Mars' because it basically changed Earth's sky to Mars' sky (laughs) and it was quite a complex algorithm that we turned into a gizmo in Nuke, which allowed us control for how much blue we take out of a shot and how much we col- orize it with another color, and it basically gave us nice clean results. "We needed the finer control because what we would find was happening was that we had a lovely dessert landscape shot on a blue-sky day and we would take the blue out of the sky but were then left with haze in the shadows of the mountain or in the shadows of the foreground. We had blue bounce light from the sky that hit into the shadows, so we were actually very careful about how much of that we removed and how much we left in. If we got rid of it completely, we ended up with something that looked like a sepia photo. That was kind of an interesting scenario where we had to fine tune that level and leave a little bit of blue into our shadow detail and not completely remove it from the haze and background and that gave slightly more pleasing results in the final color correc- tion and the DI stage at the end of post." Were you happy with the end result? "Oh yes, absolutely. Given our schedule, I was always concerned that we would get to a point where we were going to think that we were never going to get there, that we were never going to get those final, finessing touches on there, but everything really pretty much delivered on time and at a beautiful level of quality. All nicely rendered in stereo and com- posited in stereo as well." www.postmagazine.com FOR THE FULL INTERVIEW, VISIT Framestore's detailed CG model of the Hermes spaceship (top); MPC replaced plants and bushes from the Jordan landscape with rocks and craters (bottom).