Beowulf boasts the largest vfx crew assembled at Imageworks, with a team of 450. The film even exceeds the Spider-Man franchise in terms of the wide range of effects. 

Fortunately, Imageworks was able to leverage some of the technology from previous features, including Katana, the lighting software introduced on Spider-Man 3. “We realized early on that there were so many components coming into lighting, which needed Look Dev standards, that we need to tie in an asset management system,” explains CG Supervisor Theo Bialek. “We developed a plug-in for Katana that allowed all those components to come from different departments to go through an approval process and once approved they were added to a lighting workspace, which lists what should go into each shot. We kept track of approved assets from animation, cloth, which was driven off animation, and hair, which was driven off the cloth and animation. We had an automated asset system that would know when a new version of an asset was coming through, and so a lighter was always working off the most recent version of that asset for that particular shot. It meant that anytime a change happened down the pipe, the lighters were immediately notified and updated with assets.

“The shot lighting team did 210 shots out of 700+ in the movie. Doing ambient occlusion wasn’t possible on this grand a scale with 100 characters in close quarters in a Mead Hall with different light sources. Rendering shadows for all those lights and all those characters interacting was another challenging solution. We used brick maps for ambient occlusion. So in a large environment where people don’t move, we would cache that data. But you also have to deal with the elements that are moving, that are changing from shot to shot that you can’t cache, such as characters moving on a table or a prop being picked up. We had a clever system of combining cached brick maps with camera projection-based ambient occlusion. We also used indirect lighting, which has been gaining popularity in RenderMan. We store the radiance cache in a point cloud data file format, which stores the diffuse and specular lighting in shadows. We use that to do a single bounce pass, which is very useful if you have a bright spot on a character, and you can bounce light into the dark areas. This adds an extra level to the style they were going for. With such high contrast lighting, the extra bounce pass helped soften nuances around the eyes of characters.

The eyes, of course, were most crucial. Imageworks was able to better navigate through The Uncanny Valley with improved EOG, shading and CGI.

“For rendering so much data, they decided to use a foreground occlusion rendering method. You use the alpha of your foreground render and you erode it in, and you need to allow extra pixels there so that when you do depth of field in layering, you have something to blur into. But we saved 50% rendering time when you have characters moving around in the foreground. This was new to Imageworks.”

They also leveraged Surf’s Up’s wave animation technology, which was modified for the opening shots of the ocean and the storm at sea and inside the cave where Grendel and his mother live. The water inside the cave was created using shaders on a flat plane with particle simulations in Houdini for the splashes. For the opening shots of the ocean, the vfx artists created 3D water using soft body simulation in Houdini and particle simulation for foam, sea spray, rain and fog. Waves modeled with Surf’s Up’s system crashed water onto the beach.

Meanwhile, the fire pipeline was leveraged off of Ghost Rider (Houdini driving Mayas’s fluid engine), especially for the mayhem created by the dragon. It’s a system that can art direct the look of the fire. The golden dragon, which is the only fully keyframed CG character, looks almost human when it stands on two legs and reaches up, but is more familiar in other respects, save for its bat-like wings. Artists also used the Sandman fluid engine from Spider-Man 3 to help drive the snow that’s impacted by the dragon’s wings.

VFX Lead Vincent Serritella co-developed the fire pipeline. “Jerome and Bob were going more for photorealism here,” he says. “We changed the render solution to an in-house volumetric renderer that was written by Magnus Wrenninge. This was beneficial for flying through the effect and not have the image break down. We added smoke effects to fire for more natural lighting integration.” They additionally created bioluminescence for the cave sequences: this provided great interaction with water and added greater appeal as a light source. Reflective shimmering and gold lining on cave walls gave off a nice blue phosphorescent feel.