This is the first of four installments in VFXWorld’s The Chronicles of Narnia: The Lion, The Witch and the Wardrobe production diaries.

Rhythm & Hues was under pressure to create a convincing Aslan. Fans had made the iconic character the litmus test of the film’s chances at success. All images © Disney Enterprises Inc. and Walden Media Llc. All rights reserved.

I still remember the moment I first heard that Rhythm & Hues was being considered as one of the production houses to work on the visual effects for The Chronicles of Narnia: The Lion, the Witch and the Wardrobe. It’s not often that a chance to work on one of your most cherished stories from childhood comes along, and I was pretty excited, to say the least. After a lengthy process of bidding, doing a few creature tests for director Andrew Adamson, and a seemingly endless series of meetings, that chance became a reality, but eventually the excitement morphed into a gnawing terror, as I wondered: “How on earth are we going to do this?”

VFXWorld asked me to create my own chronicles of sort, by requesting that I keep a log of the goings on within our part of the production from that point onward. As with any project of this overwhelming size, my favorite tactic is to divide and conquer. Basically, this means that I need to reduce the task of the job into manageable chunks and worry about each one in a timely fashion. In that spirit, I am breaking this diary into two parts. This installment covers the visual effects version of pre-production, which includes creature construction, rigging and prelite, the development of software and pipelines and the actual principle photography of the film. The next installment will detail our actual shot production in animation, lighting and compositing.

For this movie, Rhythm & Hues was tasked with creating Aslan, the lion, and handling the majority of the battle sequence at the end of the film, which required the creation of a large number of hero CG characters and a simulation to deal with their combat. We also took on the sequence in which Aslan meets with the White Witch and is sacrificed in front of a throng of those same creatures that would appear later in the battle. For the sacrifice and battle sequences, our biggest issue was the challenge of building, rigging, lighting and controlling that many different characters across a large number of shots. For Aslan, it was the equally scary prospect of doing justice to the iconic character that everyone expected to see executed perfectly. Many an early sojourn onto the various fan websites cemented the reality that, for many, pulling off a convincing lion would make or break the film for them.

Bill Westenhofer’s favorite tactic when taking on a project as immense as Narnia, is to divide and conquer. He reduces the task of the job into manageable chunks and worries about each one in a timely fashion.

Fortunately, the work that Rhythm & Hues had accomplished in the past, and the work that I had directly supervised during that time (especially Cats & Dogs and Elf) gave me confidence that we could achieve these goals. Fortunately, I knew what our animation and fur were already capable of and knew that our gurus in the software department could push it to a new level that would surpass what we had done before. To mobilize this effort, one of the very first things we did was to sit down and draft a technology document that itemized the lists of new capabilities we would need. Big items on that initial list included improvements to our muscle/skin dynamics, fur collision detection and overall pipeline improvements to deal with tracking the multitude of characters and models in a shot. The biggest item, however, would be a crowd simulation system.

After a fairly lengthy period of investigating the commercial packages and even considering the cost and time of developing our own, we selected Massive, which had just proven itself spectacularly on The Lord of the Rings trilogy, and our early investigations and discussions with its developer, Stephen Regelous, cemented our decision. Rhythm & Hues had done some crowd work before, but we knew it would be prudent to try to take advantage of the experience many had had with the software on Lord of the Rings. One of our earliest tasks, therefore, was to set up a meeting with Stephen.

Feb. 12, 2004
We met with Stephen today and it was extremely useful in getting a handle on the specific tasks we would need to perform in readying ourselves to do the work on the film. New terms such as motion-tree, motion-edit and massive agent have now entered our lexicon. He also helped us refine our expectations with regards to what kinds of shots would be more and less difficult given the capabilities of the software. We had previs of the opening of the battle to show him, which was also helpful in letting him see exactly what we needed Massive to do. This meeting also got the ball rolling with our software developer, Hans Rijpkema, in starting to develop interfaces both to and from Massive so we could import our models and rigs, and get renderable items out of the simulation to pass to our proprietary renderer, wren.

Within our scope, everyone agrees that the centaur (a classical creature comprised of the torso of a human and the body of a horse) will be one of our toughest technical challenges on many fronts, and this also seems to be true in Massive. The software itself simulates performing agents by executing brains, which are bits of code that use fuzzy-logic to select from a series of pre-generated actions. A motion-tree is a set of these actions for a given character. You can imagine a motion-tree as a set of actions that start from a rest-pose. Each branch is the set of actions that can proceed from that rest-pose like a swing or a block. Each branch from there continues as a set of actions that can then be accomplished from the new position and so on. For the rich complex actions of a battle, this tree can easily comprise several hundred actions. For this reason, motion capture remains as the desired means to create the actions for a tree; having our animation staff create every one of these would be prohibitive. So, the challenge for the centaurs in particular was how to motion capture their actions.