In the past decade, the field of visual effects for TV has exploded into every aspect and genre of production. One of the leaders in the field is the Los Angeles, Vancouver and now Atlanta based studio, CoSA VFX.

Formed in 2009, CoSA VFX takes its name ‘Company of Science and Art’ from the original developers of the venerable compositing package After Effects. With founding partners who had worked on Titanic, Lord of The Rings: The Two Towers and The Chronicles of Narnia: The Lion, The Witch and Wardrobe, CoSA VFX brings a unique perspective to both its TV and film projects.

CoSA VFX just received two Emmy’s for Outstanding Special Visual Effects in a Supporting Role for Gotham, and for Outstanding Special Visual Effects as part of the Westworld VFX team. This recognition, along with previous nominations for Marvel Agents of S.H.I.E.L.D and Revolution, are testament to how much CoSA VFX is pushing the limits of what can be achieved in the field.

CoSA VFX recently started using Redshift as its render engine of choice for current and upcoming projects. We spoke to David Stripinis, C.G. Supervisor at CoSA VFX (who like the CoSA founders has a background in large features, with credits including Avatar, Man of Steel and ANT-MAN) about what makes the fast-paced nature of TV visual effects schedules work so well with Redshift.


Testing times
In June 2016, David was asked to assess the state of render solutions available on the market. While CoSA VFX had been using a CPU render solution for its work up to this point, the team wanted to know if there was a solution that would better meet the demands of their schedule, which at its peak in mid-season, can have up to 300-400 shots passing through the studio each week.

With the improving technology in living rooms, an increasing number of these shots would need to be rendered in 4K, substantially increasing the rendering workload.

David initially looked at a range of existing CPU renderers, then CoSA’s FX Supervisor mentioned that he should check out Redshift.

“I downloaded the trial version of Redshift and rendered a Cornell box,” David explains. “But it wasn’t any faster than rendering with other rendering solutions.”

“It just so happened that that week was SIGGRAPH where I talked to Nicolas from Redshift. I said, ‘I am evaluating Redshift and it is not very fast,’ and he gave me this puzzled look of ‘what are you talking about?’ Nicolas said that rendering the Cornell Box was probably too simple and that I should try rendering something really complex to see the difference.”

With this advice, David returned to CoSA VFX, took their heaviest asset from Gotham, the Arkham Asylum model, and set it up to render with each solution he was evaluating.

The result was a surprise for David: “The difference between Redshift and the other renderers was not a factor of two or three times quicker; Redshift was literally an order of magnitude faster. The shot was taking two or three hours in the other renderers while taking two to three minutes in Redshift with no optimization and I was like, ‘Ok, that’s crazy!’”

Game-changing speed
This impressive rendering speed led CoSA VFX to begin to incorporate Redshift on several projects.

“Redshift is perfectly suited for TV work. The entire model and textures can sit within the video RAM of a standard video card, even though Redshift can swap out the system memory, it doesn’t need to. Redshift just loads it in and goes to town,” says David.

The first show that CoSA VFX used Redshift on was HBO’s Westworld. The shot called for some digital rocks and train tracks to be added to the scene.

“It was enlightening for a lot of people. As I did my renders and sent them off to the compositor, she sent me a message asking for a couple of specific mattes.”

“I went up to her desk about 25 minutes after she asked for them. I said, ‘About those mattes…’, and she asked, ‘Do you need me to explain them better?’ And I said, ‘Oh no, they are done!’ To which she replied, ‘What!?! That was a 125-frame shot?’”

When David got back to his desk the compositor had sent him a message. “There is no noise, what is this?” This kind of reaction from team members kept happening on Redshift-rendered shots.

Before Redshift, CoSA VFX had been working with the expectation that any 3D shot would have a maximum of two iterative passes before moving to compositing.

David noticed that many of the revisions that would normally be fixed in compositing could actually be re-rendered in minutes by the 3D department using Redshift. This gave the compositing department more time to work on the look and story of the shot rather than dealing with 3D fixes.

Working on Gotham
“Redshift really came into its own on the Gotham season 3 episode ‘Mad City:Red Queen’,” explains David. “We had to recreate Gotham City completely set in the 1950s. We had to build eight square blocks of city and render it out for fourteen shots in the space of a week and a half.”

CoSA’s CG team created an assembly line: one person doing modelling and UVs in Autodesk Maya, another texturing in Substance Painter, and another working on look dev back in Maya using Redshift. The finished models were then referenced as Redshift Proxies into David’s master Maya scene file for final lighting.

The team worked hard at placing extra details into the models. For instance, instead of having mirrored glass for windows, rooms were built with specific windows on buildings, which enabled convincing parallax as the camera moved through the scene.

Even with this level of complexity, overnight, Redshift was able to deliver multiple shots of over 500 frames each for the compositing team to start to work with.

“At this point we only had a limited amount of render hardware for Redshift. We were very pleased with Redshift, but it was still an experiment to see if it could become our primary render solution.”

Even though CoSA VFX had developed a system of slaving workstations to GPU render nodes, which would leave the traditional CPU farm free for work from teams such as compositing. David realized this solution would not be sufficient for the pilot season crunch, when seasons finales are being worked on simultaneously with pilots for new shows. CoSA VFX therefore decided to invest in a GPU render farm. According to David, this “makes jobs fly through the farm”.

Optimizing the possibilities
David notes that with this great render power, comes great responsibility for the CoSA VFX team: “The danger of Redshift is that it can make you lazy when optimizing your scenes. You take a scene that can take twenty-five minutes to render in a CPU renderer, you put it into Redshift and it will render in two minutes. Then when you up the settings in Redshift you are back to 25 minutes. So I have become more diligent and started to ask questions such as, ‘Do you really need 145 point lights in that scene?’”

“There is always a balance with the amount of time it takes an artist to optimize a scene, versus the time saved rendering the optimized scene. If you can save 30 seconds a frame on a shot with five or six render layers, you are talking about saving five minutes a frame. Even in Redshift, that’s the difference between a shot being ready at nine in the morning versus a shot being ready at three in the afternoon.”

Creative experimentation
Beyond getting frames out on time, David reveals that Redshift has enabled the team at CoSA VFX to experiment more with different creative options, something that would not be feasible with other renderers.

“Everything comes from speed. What Redshift allows you to do, is to be flexible. If a compositor asks you to do something, you don’t have to throw up your hands because of the rendering time… You can be experimental.”

In a sequence for Gotham, ‘The Council of Owls’ oval table had a model of Gotham city rise up out of it. The original vision for the table city was for it be made completely from marble which would be underlit, with sub-surface scattering making certain areas glow. This meant that the rivers and other features could be revealed on the map.

“It was a really great concept,” says David. “We created some more versions as we were starting to incorporate Substance Painter into our pipeline and wanted to experiment ourselves. We created one out of concrete and one out of brushed metal, with black carbon paint with burnished and scratched edges revealing the rivers underneath. I showed that to VFX Supervisor Tom Mahoney, who said, ‘Wow, that looks even more awesome, let’s send that to the client. And the client said, ’That’s what we want.’”

“VFX is a collaborative art. Not just within the team at CoSA VFX, it’s also a collaboration with the client. For myself as an artist, being able to experiment and show the client new options because I have already shown them what they originally asked for is great.”

“To have a renderer giving you visual feedback almost as fast as a game engine is insane. You just get better at stuff because of the immediate feedback. You develop an innate connection between ‘this is what my hands have done’ and ‘this is what my eyeballs are seeing’, which lets you understand your tools so much better.”

David mentions that the only downside comes when working on old scene files: “It does, however, cause frustration when you are not using Redshift. When you have to go back to an old scene file and you are not able to use Redshift, you go, ‘Oh God why!’.”

Looking to the future, David thinks that the industry is about to go through a change which Redshift is a big part of: “In order to get up to speed with GPU rendering, large facilities will require a huge change to their CPU farms on a global basis. Suddenly, with Redshift, you can have a 150 person company that can take on a 300 person company. You can take a risk with a few $500 licenses for Redshift and $10,000 of video cards. If your team is up to the goal, you are not being held up by not being able to render in time, which is massive.”

With the scale and creative ability shown by the team at CoSA VFX with their huge variety of work on some of the coolest TV and film projects coming in the fall of 2017, there is no doubt that the CoSA VFX team is making the best use of Redshift.