Delivering VFX for a sequel to a beloved franchise is never easy, but Framestore handled it with ease, tackling more than 1,000 VFX shots and CG assets for Marvel’s “Guardians of the Galaxy Vol. 2.” We got the opportunity to chat with Framestore CG Supervisor Sylvain Degrotte and VFX Producer Sophie Carroll about their work on the film.

Guardians of the Galaxy 2 Vol. 2 © 2017 Marvel Studios. Image courtesy of Framestore.

Tell us about your character work on “Guardians of the Galaxy Vol. 2.”

Sylvain: We worked on hero characters Rocket and Baby Groot. Having helped create Rocket for the first film, the sequel gave us an opportunity to refine him with improved animation and a new costume. Using a practical suit for reference, we deconstructed the costume’s pattern and reconstructed the suit in 3D using a tool called Marvelous Designer. We then outfitted Rocket with the suit, making minor tweaks to the costume to make it more realistic. All of the simulation work for this was done in Autodesk Maya.

Guardians of the Galaxy 2 Vol. 2 © 2017 Marvel Studios. Image courtesy of Framestore.

The sequel called for an all-new look for Baby Groot – expressive, but not too human; a baby, but still an alien; made of wood, but not too old. This was challenging because when wood details are added, the eye perceives it as wrinkles. We also had to ensure his face conveyed realistic expressions to connect with the viewers, while still appearing to be made of wood. Using proprietary tools and coding in Maya we were able to create a more authentic character that feels made of wood by creating a method of deforming the character mesh. The tool conserved the wooden stiffness in certain areas, while stretching to convey expressions in other areas.

What reference materials did you use?

Sylvain: We used a lot of footage of real raccoons for Rocket on the first film and then built on that for the sequel, paying careful attention to ensure continuity with the first film. Rocket had to feel like the same charming, wise-cracking character established in Volume I. For Baby Groot, we reused mechanics from adult Groot in the first film and also watched kids running around and playing for reference. The challenge was finding a balance between making him feel like a young character, but not too human.

Guardians of the Galaxy 2 Vol. 2 © 2017 Marvel Studios. Image courtesy of Framestore.

Sophie: We also had performance references on set and voiceover performances with headset cameras. Director James Gunn’s brother Sean Gunn was the on set stand-in for most of the characters, and James provided the reference performance for Baby Groot and his dancing sequence, which was a lot of fun.

Which tools did you use in your character and costume design workflow?

Sylvain: Our team used Maya to model almost everything. For displacement and detailing on the models we used ZBrush, but the base model was always done in Maya. To create the cloth simulations for the costumes and simulate loose fat on skin for the giant Abilisk character, nCloth in Maya came in handy.

Please tell us more about your modeling and UV work on the film.

Sylvain: We used Maya to model nearly everything for the film, and it was incredibly useful. Each tool’s layout and multi-functionality when combined with already familiar shortcuts vastly sped up the time it takes for assets to be modeled. One of the most useful new tools by far is the Quad Draw tool, which allowed us to rework the edge flow of our polygonal meshes without needing to continually switch between programs. The integration of the Mudbox tools into Maya 2017 also allowed us to tweak hero characters on a shot-by-shot basis, while looking through the camera’s point of view. It would have been difficult to meet client expectations without this.

Guardians of the Galaxy 2 Vol. 2 © 2017 Marvel Studios. Image courtesy of Framestore.

How did you approach character animation, shading and lighting?

Sylvain: We used 2D keyframe animation to animate primary characters like Rocket and Baby Groot, and motion capture for some of the background characters, like the Ravagers. All of the animation was completed in Maya. For shading and lighting, we relied on a customized version of Arnold for rendering; that gave us the flexibility to do exactly what we wanted. Shading was all custom-made in Arnold, and we wrote our own shaders and have our own proprietary shading models. We also used our propriety software for lighting, and did geometry translations that could be implemented in Arnold.

Tell us about the volume of shots and assets you contributed to the film.

Sophie: We worked on more than 1,000 shots and assets, which resulted in 104,737 client notes, 12,900 tasks and 100,000 submission iterations. Shotgun was instrumental in helping us juggle all of it. We have an internal asset database that records all data and links into Shotgun, which is our main database for reporting production information. Shotgun also helps us manage scheduling and maintain internal and client reference notes. It’s been great for our team because it’s fairly straightforward to pick up and use, works across multiple production facilities, and just keeps getting better with each new version; we also rely on RV in Shotgun to review dailies. One of my favorite features is being able to create annotated notes that the artists can easily see and access.

Guardians of the Galaxy 2 Vol. 2 © 2017 Marvel Studios. Image courtesy of Framestore.

What were the most challenging sequences and aspects of production?

Sylvain: The most challenging aspect of our work turned out to be the Groot’s opening dance sequence, which includes 4,000 continuous frames of Groot dancing through a city made of gold. Considering the reflective nature of the city, we had to ensure every aspect of each frame was perfect and true to reality. Each frame had effects and reflection passes rendered under the same lighting conditions, leaving no room for error.

The sequence also features the Abilisk, a giant octopus that the Guardians fight. Because the character is translucent and you can see through its skin, we had to develop the internal and external structure and render the internal geometry. Typically you only have to worry about the external geometry, but here, we had to R&D the interior structure, run the simulation on it and then attach the skin on top of everything, so we developed a new subsurface scattering shader to render the character. We modified our shader to create a higher level of accuracy and realism, so that light would go through the skin, hit a different surface and reflect out with some scattering, allowing the internal structure under the skin to be visible from the camera point of view.

We were also challenged with creating the sky, which played a huge role in the opening sequence. As simple as it sounds, we had to create realistic moving clouds. Making them appear as natural as possible took a lot of R&D and time to render.
Guardians of the Galaxy 2 Vol. 2 © 2017 Marvel Studios. Image courtesy of Framestore.

Tell us about some of the highlights working on this film.

Sylvain: We worked with such an incredible team and the quality of rendering we were able to deliver is impressive; the stability of the rendering algorithm and the integration of all our assets with the live action plates was a phenomenal achievement. When you look at the movie, you have to realize the scope of the effects and the amount of effort it took to make each shot seamlessly integrate together. In particular, when you watch the Baby Groot dancing sequence, it’s like a mini-movie. It was a huge undertaking and our team was really fortunate to have the opportunity to work on this project.