Subnautica Below Zero: Making a Trailer in ZBrush & UE4

Introduction

80.lv: Please introduce yourself and your team. What do you do? What projects have you contributed to as a team?

Dave Cullinane, Executive Producer: We are REALTIME, an animation and VFX studio based in the UK that specializes in creating work for video games, automotive, TV, and film clients. Our team is going to tell you about the process of working on the Subnautica: Below Zero project. Since forming in 1996, our work in these areas has become increasingly diverse, with our teams creating everything from high-end pre-rendered trailers, VFX, key-frame animation services, online car configurators through to real-time VFX. However, it is probably our pre-rendered CG trailers for the gaming industry that we are still best known for. 

Dave Cullinane, Executive Producer: The trailer for Subnautica: Below Zero is the third we have produced for Unknown Worlds, the developer, and publisher of this hugely popular game. Following on from the launch trailer from the original game, and the subsequent DLC, this third trailer is our best yet and is representative of the scale and ambition of the game. 

Creating the Characters and Creatures

80.lv: How did you work on characters and creatures for the short? How did you model and rig them? What tools did you use for production?

David Weaver, Senior Character Artist: We started with the concept art provided by the client and created a series of concept sculpts in ZBrush. Once those were signed off, they were retopologized so that they could be rigged, and the final sculpt details were added. Texturing was then completed in Substance Painter, before bringing the assets back into 3ds Max for look development using V-Ray and groom, which was done in Ornatrix.

Nicolas Seck, Animation Director: We animated completely in 3ds Max, thanks to the high level of attention and care from the team in crafting the models of the creatures and our hero character. The rigs for the creatures were custom-made, with the integration of different tools to fit our needs. For instance, we integrated the use of sine waves to generate a nice flow in the squid shark’s tentacles.

We spent quite a lot of time designing the rigs so we could control as many details as possible, such as the jiggles and the muscles flaring on the Snow Stalkers which were all individually animated by hand. We had one rigger in the team, Ahmed Shalaby, who worked within a very tight deadline of fewer than two months to do the job.

The hero character’s body was built using a 3ds Max base and had three variations of costumes with specific needs for each. This was crafted by Ahmed, with the support of our lead animator John Batchelor.

The facial rig was managed brilliantly and impressively in just a week by Will Eades who managed to satisfy all our requests to control the face, down to the tiny details. Overall, we had a team of 7 animators (John Batchelor, Ciaran Dempsey, Mario Linares, Dmitriy Tunik, Kimberley Watts, Will Eades, and I) who were involved across a two-month period. We divided the trailer by sequence, and each animator had the ownership of their own chunk to preserve the continuity of style. I then spent a few days refining the shots and making sure that they all reached the level of detail and quality that our client expected.

Creating Movement

80.lv: Could you discuss your animation approach? What are the tricks when setting up movements for such shorts? What tools did you use? Could you discuss some of the more complex movements in detail?

Nicolas Seck, Animation Director: We started by creating a detailed previsualization, based on the storyboard animatic provided by the client. This was to establish the right framing and length for each shot to get an efficient visual narration. We also wanted to establish the foundations of the project as much as possible, even though this was not locked as some scenes were removed and others had more impact in the final version.

We studied the game animation as a starting point, but we also wanted to bring in some extra details. We collected many references for each scene which helped us establish the type of energy that would suit the creatures’ behavior.

The trailer is made up of the contrast between calm moments with sudden tension, which gave us a good dynamic to work with.

For the hero character, we were very much inspired by Ron Swanson, so we tried to find facial expressions and attitudes that would best serve the performance we were looking for. We also did a mocap session for his performance. This was used more as a guide and 3D reference, rather than using the data for the animation – although we did for a couple of shots where it delivered a good base to work from.

We also filmed ourselves for reference. This helped us to achieve the level of detail and nuance we wanted in the close-up acting moments. There it was all about the subtle micro-expressions which tell a lot more than any dialogue could have done.
We took extra care to make sure that the shots flow nicely from one to the other, even though the environment and time are constantly jumping to something different. We wanted to drive the audience’s eyes to specific pieces of action, so the choreography had to be well-timed. This was particularly tricky to do with the attack sequence in the snow as there were several creatures as well as our hero character.

We also tried to introduce details here and there which connect the scenes to each other, like the plaster on the hero's nose or the damaged rail of the submarine. The difficulty was finding the right balance between realism and expressiveness with a hint of exaggeration for the more comical moments.

Environments

80.lv: How did you create environments for the project? How did you approach the underwater part and the upper winter part?

Danilo Lombardo, Environment TD: We developed both environments at the same time, inside 3ds Max. Very early in the process, our animatic team worked up very simple blockouts and set dressing using game assets.

The cliffs played an important part in the overall look of the underwater sequence, so we displaced them in the viewport and then added more surface details for the render. We created a set of hero plants, so we could choose which ones would look best for close-ups. All the texturing work was handled both inside 3ds Max using procedurals and Substance Painter. After the cliffs were completed, we scattered the vegetation on them using Forest Pack, which we also used to colorize some clusters. We achieved a bioluminescence look with simple self-illuminating shaders.
A more traditional ZBrush approach was used for almost all the environment on land, where we sculpted icy cliffs and rocks.

We covered everything with snow using TyFlow, with a simple setup capable of outputting a thin layer on top of objects, or a little mass based on gravity and some voxelized spheres. Nothing too fancy but it proved to be very successful when introducing and controlling any snow in the scene, which was also sculpted in ZBrush.

We undertook some RnD for the snow and ice shaders, using our experience working on other trailers, including Game of Thrones: Winter is Coming, and the power of Smart Materials in Substance Painter. These textures were instanced across a variety of different assets, helping us maintain consistency, as part of a bigger shading network with features for procedural dirt and translucency. The final result is realistic snow that looks like it belongs to the beautiful world of Subnautica. 

Working on Water

80.lv: Could you also discuss simulating water and waves?

Daniel Lloyd-Wood, FX and Pipeline TD: The water itself was a Houdini FLIP simulation with a white water solve. There were actually two sims blended, one mid-resolution to create the bulk movement of the water and then a higher resolution sim to create the more detailed runoff water.

Both sims were blended into an ocean surface using the ocean tools in Houdini. The trickier part of the shot was the floating ice. That was achieved by using the velocity field of the water sims to drive a separate particle-based RBD sim. This allowed the movement of the water to be incorporated with accurate collision behavior for the ice chunks. Any ice that moved above the water surface level was pushed back down to stop chunks of ice floating in the air. 

Lighting

80.lv: How did you set up lighting scenarios for the short? What post-production settings did you tweak for different parts? What rendering engine did you use for production?

James Kirkham, Lead Generalist/Lighting TD: Each environment was separated and assigned its own lighting setups. The underwater shots were probably the most unconventional with everything being lit in an atmospheric tank to achieve a murky scattering of light. Animated light throws were then created to achieve a subtle motion to the light shafts. 

The atmospheric shots were pretty expensive, so the base render used fairly conservative samples and noise threshold. The atmospheric pass was extracted and denoised, to clean it up.

The rendering engine used for production was V-Ray 4.

The Main Challenges

80.lv: What were the main challenges? How much time did it take to finish the whole thing? What was the most time-consuming part? What parts of the project make your team proud?

Stu Bayley, Art Director/Director: There are always many challenges in any CG animation project, but on this one, I would say the main challenge was the subtle comedy aspect of the trailer. It is so easy to play for laughs or try to make something funny, and as we found out when we did that through the performances it became staged and slapstick. Finding that balance of the mundane daily grind becoming increasingly dangerous was the key to building the humor naturally. So yeah, comedy is very hard to get right, and I hope we did a good job of not overplaying it.

The project took around 3–4 months to complete. A big chunk of that is the creative process in preproduction and just getting the idea to work and flow. We worked very closely with the client on that, and they had a big input to that setup which was great. 

The most time-consuming part tends to be the rendering on any high-quality pre-rendered trailer, but that is just a given in this industry. Other than that, this project featured a lot of simulation, whether that be billowing fur on the Snow stalkers or the clothing of our hero character. We really wanted to sell the visceral experience of the protagonist so we decided one way to do that would be through the realism of the simulation work. We felt even though it is not a photorealistic-looking world, you would feel more for the characters if the level of detail was relatable. I think we found a nice balance and achieved our goal.

The team is most proud of the small details in this project. Again, we latch onto small details as being relatable. So, sipping on a hot coffee before the daily grind begins, with the steaming aroma wafting up your nostrils, or beating down into the icy ground as warm breath vapors escape through your mask. It all adds to the viewer experience, and it matters a lot! We feel this level of attention to detail is what we are most proud of in our work here at REALTIME. 

REALTIME, Animation and VFX Studio

Dave Cullinane, Executive Producer

Stu Bayley, Art Director/Director

David Weaver, Senior Character Artist

Danilo Lombardo, Environment TD

Nicolas Seck, Animation Director

Daniel Lloyd-Wood, FX and Pipeline TD

James Kirkham, Lead Generalist/Lighting TD

Interview conducted by Kirill Tokarev