The filmmakers always had an onset human performer as a shooting reference. An actor dressed in a blue or green suit played the Werewolf (above), the Bear and Aslan, which gave the other actors something tangible to react to.

The Mother of all Miniatures
A critical decision was taken early on to create the film's major environment -- Miraz Castle -- as a miniature. A key location in the storyline, it was featured in more than 300 shots. "In the first movie, we had created the castle for the end sequence digitally, but it was a handful of shots," Wright remarks. "Miraz Castle played a central part in Prince Caspian. We already had a huge workload in terms of digital characters. By creating the castle as a miniature, we saved our digital resources for elements that couldn't be created any other way."

The castle was built at Richard Taylor's Weta Workshop, New Zealand, where most of the Lord of the Rings and King Kong worlds had been created. At 1/24-scale, it ended up being the largest single piece ever constructed by the studio. It was so large that the team had to tilt it at 30° for the camera to be able to capture aerial shots on stage. Another version was built at 1/100-scale and included the whole environment with a nearby village and background landscape. Weta Workshop also constructed separated miniatures of the village and the castle courtyard. The plates were later enhanced by sister company Weta Digital, under the watchful eye of VFX Supervisor Guy Williams, and combined with live-action shots of the actors on partial castle sets. "I feel that you always get better results when you have real elements in a shot," Wright adds. "They grab the viewer's attention and help sell the CG portions of the image. It was one of the advantages of having a real miniature that we could shoot, light and check in the viewfinder. We were able to get really tight on the walls and the surfaces would hold perfectly. We used the same approach for our crowd scenes: we always had a group of real extras in the foreground, and our CG army in the background. We tried to keep it all as real as possible."

Trying New Approaches
Having learned from the experience of shooting the first movie, Wright took new approaches to capture the visual effects plates featuring CG creatures. The first thing was to discard on set motion capture. On The Lion, the Witch and the Wardrobe, the technique proved very useful for Faun Tumnus, but not for the crowd scenes. The vendors ended up not using a lot of that data. "We decided to go for a more 'guerilla' approach on Prince Caspian," Wright notes. "We used three HD 24 fps 'witness' cameras to help capture the actors' performance. We would move them around the performers in order to triangulate their position in 3D space. Basically, it's the same technique that ILM used on Pirates of the Caribbean 2 and 3: you capture the live performance from varying angles, and then use that footage as a template to animate the corresponding CG character. It allowed us to add CG legs to the two-legged creatures, or a CG horse body to the Centaurs.

"Just like on the first movie, the performers were wearing blue pants or green pants, depending on if it was a day or night scene. The second thing that we did on set was to always have a human performer in the frame as a shooting reference. Most of the time, it was actor Shane Rangi in a big blue or green suit. He would play the Bear, the Werewolf, Aslan… His presence on set allowed the other actors to have something tangible to react to."

Building Creatures and Crowds
When the first movie had wrapped, Wright had gathered all the CG assets from the various vendors. Eventually, due to pipeline issues, most of the creature rigs had to be rebuilt from scratch by the new vendors. Textures were extensively upgraded too. That was the case at MPC, where the team led by VFX Supervisor Greg Butler was responsible for the creation of a huge menagerie: gryphons, big cats, wolves, bears, centaurs, minotaurs, etc. Some were full CG creations, others were a combination of live-action and CG body extensions. All required the development of complex fur or feathers. While working on 10,000 BC, MPC had developed a brand new grooming and lighting package called Furtility. The tool proved perfect for the array of creatures that had to be created for Prince Caspian. It allowed artists to vary the fur's look, texture and behavior creature by creature.

MPC used Furtility to create the new character Reepicheep, a swashbuckling mouse-chief.

The team was also responsible for creating a key new character, swashbuckling mouse-chief Reepicheep. The rodent was entirely designed by MPC's art department, and later voiced by Eddie Izzard. Captured on video, the comedian's performance provided a great reference for the animators in charge of bringing Reepicheep to life. Once again, Furtility enabled the team to create a detailed and believable fur. "Reepicheep is one of those characters that turns out to be quite difficult to nail down in animation," Rogers observes. "The question was: how much do you want to anthropomorphize him? How much can you open his shoulders before he loses his mouse-like quality? We also had to determine how he went from quadruped to biped position and reverse. Luckily, Andrew Adamson was very articulate in what he wanted. He would act out a whole scene in front of the animators, and very precisely show them the kind of emotion a character had to convey. Andrew was really instrumental in bringing these characters to life from an artistic perspective."

The final battle sequence proved to be quite a challenge for MPC. "We had about 5,000 Telmarines (human warriors) facing off 1,000 Narnia creatures of all kinds," Rogers adds. "For both armies, we had extras in the foreground in just about every shot. Then, MPC populated the background using their procedural crow system ALICE. The characters were animated using motion capture data augmented with key-frame animation when needed. Interestingly enough, the trickiest shots were not the real battle shots, but the ones in which the armies were standing still. It turned out to be real difficult to create a natural animation for characters that were just standing there. You have to find the right balance between motion and stillness."

For the centaurs, a variety of techniques were used, depending on the action that was required and the framing of the shot. A centaur could be a human performer with a CG horse body extension, or a real horse with a CG human torso extension, or a fully CG character.