Head of lighting and digital effects supervisor at DreamWorks, Dave Walvoord came to ‘Kung Fu Panda 2’ having worked on the first Kung Fu Panda movie. Although the lighting team had done much of the groundwork on that first production, they weren’t necessarily trying to re-invent those looks on the new film.

The first time around, they defined the physics and rules for light behaviour within the movie’s universe. “For this project, we wanted to keep that set of rules but follow them much more consistently, push deeper into this world and explore it and flesh it out. We could also take advantage of new software developments at DreamWorks to add to it,” he said.

Light Behaviour
Their own understanding had also grown. Interestingly, by going out to SIGGRAPH and schools to lecture about what they had achieved for the first movie, Dave had considerably improved his understanding of the lighting universe they had created – how light should behave and how the characters should look. By the time they came aback to the second film, they were prepared to apply their physics more aggressively and consistently. The production designer Raymond Zibach was also keen to take advantage of their confidence and ability to give the looks a new direction and use stronger colours.

This was Dave’s and his team’s first stereo film. All of them were very comfortable and skilled in the 2D realm but as soon as they began working and experimenting with stereo, they found many techniques they had previously relied on were suddenly not going to work. So they actually went back and chose two sequences in ‘Kung Fu Panda 1’, converted them to stereo and completely re-rendered them to see what their world would look like in the new medium – before starting to plan their second film.

“This exercise made us realize that relying heavily on very shallow focus, as we had done earlier, wasn’t as viable here. We had used it to direct viewers’ attention to a specific spot in the frame. This world is very ornate with rich textures. It’s one of the film’s trademarks but it’s easy for viewers’ eyes to wander across the frame,” he said.

New Tricks
Without that control over depth of field they had to learn some new techniques. They changed camera moves and angles but also introduced many more volumetrics, such as god rays, fog and atmospherics, and used them to interact with characters. Dave said, “This also adds tremendous richness in stereo, but our motivation had been mainly to regain control over the audience’s attention. Fog behind a character could mask distractions in the background, for example.

“It became a learning and adaption experience. We still maintained our regular CG pipeline – storyboards, layout and camera, animation followed by lighting, which means the camera and lighting were somewhat separated. We continued to focus on shaping the lighting in each frame, but kept the staging in mind.”

The production designer, VFX supervisor and head of layout planned the entire movie between them, while Dave’s team interacted mostly with the surfacing department, who in turn interact with the modellers, and work with them on textures and fur. Dave’s relationship with the head of surfacing was very direct. Together they fleshed out the assets in pre-production and exchanged revisions to improve looks. They also aimed to make all surfaces easy to light.

Fur Shader
Dave said, “One shader we re-wrote after ‘Kung Fu Panda 1’ was the shading model for fur, especially with regards to global illumination. Fur is always a challenge for lighting, and the updates made it easier to work with and more consistent, though it still needed occasional tweaks. Our trickiest creature was the peacock, whose feathers and odd shape made him much heavier to deal with. The thin S-curve of the neck tended to light unpredictable. We applied real translucency on all of his feathers, which added to the richness of his looks and how the shadows filled in, using natural backlighting. Although this added to the time we had to spend on him, such characters are a temptation for the lighting team to experiment on.”
The peacock’s arrival into the fortress added a new kind of scene and lighting to the film. It opens with the camera running across the water and reveals a very colourful cityscape, warm light with cool shadows. As the peacock enters, all colour drains away, creating a transformation to a stark, white, sun-bleached look – combined with a blood red sky with hints of red in the shadows. The production designer wanted to produce a striking effect, demanding a very stylised and unnatural lighting scenario.

The team met the challenge, but Dave explained that people know intuitively how light should behave. This is why highly stylised looks are hard to push convincingly. Vision is our primary sense, and we are hard to fool. It can be fun to experiment but the result has to be believable – otherwise the entire story about Kung Fu fighting animals falls apart.

Breaking Rules
Animators do have an advantage in being able to complete all models, textures, cameras and action before trying to tie these together with lighting. Contrasted to live action, integration isn’t as much an issue as believability. The control an animator has over looks is something Dave really likes about animation – the ability to break rules to create a new universe. Consistency and setting valid rules are the important factors.

He maintains a strict regard for physics. “Even for those extreme looks, the goal is to cheat physics as little as possible and base a lighting design on reality. When lighting elements like water, metal or diamonds, for example, our job isn’t lighting the object but the environment around it and then revealing what that object ‘sees’ – it will reflect and refract the light in this environment.”

Dave’s team do all of their work with DreamWorks’ proprietary tools. What he finds the most beneficial about this software is that, across the company, all the tools are made to work together. “Commercial packages are made specifically for modelling, or animation, or lighting. They are also made for a single artist working in isolation. The software here fits the different applications together and is massively scalable so that teams of hundreds of artists can work together.

New Generation
“Right now, a major initiative is underway at DreamWorks for a new generation of proprietary software and to re-write all of the tools. Meanwhile, when we need an update or a special tool for a project, we make a request to the R&D team and they can usually help. This time, I have a new volumetric renderer and the fur shading model. These both made a huge difference to the looks.”

The movie’s final battle sequence brought some special considerations because it brings together all characters, crowds, water, the complete city, even the peacock – all together, fighting it out. That was the technical side of it. Creatively, it was especially difficult because the lighting was very dark and it was essentially a two-colour scene, red and blue for fire versus water. “Because objects were losing their local colour, they were hard for the audience to identify. Including so much action with these factors meant we had to ensure that the audience always looked where we wanted them to. We had to remain aware of the dramatic intention and not disturb the flow,” said Dave.

A Lighting Life
“However, it’s usually not these big climactic sequences that you get stuck on. You anticipate those and plan for them. It’s the little ones that can surprise you. In one scene when Po and Tigress are talking in a boat on the river, the action going on in the boat wasn’t a problem but the environment behind it was. We hadn’t built the sets properly yet and had to put the whole scene together on the fly.”

Dave has now been working nine years at DreamWorks, staring as a pipeline technician with lighting as his strong point. “When CG filmmaking really began to take hold, I was still at Blue Sky and I helped work out how to actually make a movie in the medium. I was working  on a pipeline for it, which is how DreamWorks became interested in me. Eventually, though, I felt that this kind of work was pulling me away from creating images, which is what interested me in animation in the beginning. So I came back to it through lighting. I believe lighting can enhance stories and emotions in films as much as music does.”

Words: Adriene Hurst
Images: Courtesy of DreamWorks Animation
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