The old, and somewhat amusing cliche - it's not size that counts - truly has meaning for The Borrowers. In their new movie so originally titled The Borrowers, several thousand of them manage to overpower the wicked John Goodman's hideous hair style. Although the Borrowers have appeared on the TV screen many-a-time, this is their first big-screen performance, and as many of them as possible wanted to be a part of the movie. With some scenes containing large crowds of borrowers, you can imagine that the visual effects crew had a pretty hard time placing several hundred six-inch-tall actors seamlessly in the same shot!
London based effects house, The Moving Picture Company was the main studio producing work for the movie, The Magic Camera Company played the role of the second major effects house, and Framestore and VTR got a hand in with some overflow effects work. Perhaps the most interesting aspect of The Moving Picture Company's work was the crowd scenes at the end of the movie, where they created many hundreds of digital borrowers. More interesting still, the CG characters created for The Borrowers totaled over 1000, while the current block-buster Titanic's digital character count was around 700.
All of the characters in this shot are CG (apart from John Goodman), and were composited onto the shelves.
Click for a larger image.Visual Magic caught up with digital effects supervisor Paul Franklin, whose works includes Hackers, and perhaps more famous National Lottery Adverts, for a chat.
VMM: Was the Moving Picture Company the only effects house that worked on the movie?
PF: Well, The Moving Picture Company was one of the two main visual effects shops that worked on the Borrowers. All of the Moving Picture Company's work was done through our subsidiary company called Digital Film which, as the name would suggest, specializes in digital effects for film. We handled about 180 shots, roughly two thirds of the work on the film.My job was to supervise all the 3D CGI that was done here. In all, I worked on the film for about ten months.
VMM: To what extent was 3D used in the movie, what sort of things did you decide to create in CG?
PF: A large part of what we did was prop-replacement and FX elements like particle smoke, lighting effects, etc. We created things like a CGI birthday candle which is used by one of the tiny borrowers characters as a torch, making it as CGI rather than a prop allowed us to animate beads of wax running down it's sides and also to get the fall-off of light right for something that small. If it had been a prop it would have just looked like an over-sized candle. Another quite involving job was to create adhesive sticky-tape which is used to wrap up John Goodman's head towards the end of the film, this involved many days of careful rotoscoping and painstaking animation.
However, probably the most challenging, and rewarding, task in 3D was the digital stunt replacement of Jim Broadbent's Pod character in the sequence where he runs round the kitchen to rescue his son. This required a photo-real model to be built of the actor from cyberscan data and photo reference. We then had to import the motion control camera data from the real set into our 3D systems to get an accurate match-move of the shot (which was over 600 frames long and with no cuts). The animation of the character was then achieved through a combination of motion capture -performed by both the actor and his stunt double- and hand-driven keyframe work.
In this scene, the character running round the kitchen is actually CG, animated via motion capture by The Moving Picture Company's subsidiary company Digital Film.
Click for a larger image.Finally we finished up with our biggest shot, a huge motion-control crowd scene where we had to add over 1000 digitally generated humans to expand the live action elements.
VMM: Would you compare the movie in any way to Titanic, in the sense that you both made extensive use of digital actors? were there any similarities?
PF: Well, they are two very different films but the basic approach to the problem, i.e. motion capture, was the same.I suppose one similarity is that we both used the same type of motion-capture system - Oxford Metrics Vicon system - and in fact our Borrowers work is on their [Oxford Metrics] reel next to the Digital Domain stuff. The biggest similarity was the sheer number of characters in shot at one time. I think we won with 1000, they topped out at around 700 or so, but I could be wrong. They also had to match their mocap figures into motion control camera moves like we did. Another similarity would be that we had to take capture and then extend it for death-defying stunts.
VMM: I know Digital Domain used a technique called Rotocapturing which I believe that they invented - did you use this technique or didn't you know about it until after your work was done?
PF: Rotocapture, as I understand it, is basically a process where you use captured data as a reference for your final keyframed animation. To that extent our approaches were very similar, the difference being that DD did some extra work to speed up the process. What we spent more time on was developing technologies to assist the blending of motion capture together.I don't think knowledge of what DD did with their mocap would have radically altered our approach to our mocap shots.
VMM: Why did you decide to use to use CGI in these scenes rather than composited bluescreen shots of actors?
PF: Well, there were two main reasons for using CGI for both the kitchen scene and the crowd scene.Firstly, and most importantly, it was not possible to find a bluescreen stage large enough to accommodate the area needed for staging the shots as live action. In the crowd scene we would have needed a studio with a two hundred foot ceiling to accommodate the oversize set!
Secondly, using CGI for the kitchen shot, and to a lesser extent the crowd scene, meant that we could do things that would have been totally impossible with a live stunt performer. In the pole-vault section of the kitchen shot the stunt performer was motion captured jumping only a couple of feet, in the finished shot this was extended and speeded up so that he jumped a scale distance of around thirty feet - the speed that he was moving at would have probably killed a real person.
In this shot, the borrowers are all live action, shot against a bluescreen and composited into place.
Click for a larger version of the image.VMM: What software did you use?
PF: Most of the 3D was done with Alias PowerAnimator v7.0 - v8.1. All the motion capture data was prepared by Oxford Metrics and prepared with their own software. We also used our own proprietary 3D animation system for particle effects. Further custom code was written to import the motion control data and convert it to Alias format animation, we also wrote our own biped-type plug in for Alias. Morphing was done with Elastic Reality on SGI. Paint and texture work was done with Photoshop, Matador and Studiopaint 3D, all running on SGI. Video temporary versions of the shots were made in Henry and Flame.Final compositing was performed with Cineon and Inferno running on SGI.
VMM: Were there any serious problems during production?
PF: Generally, every production that I've ever worked on has had problems, most of which revolve around time and money and lack thereof. Aside from the usual bottlenecks of waiting for neg-scans and getting go-aheads, the only really big problem we encountered was with the sheer amount of data generated by our crowd scene. Each fully 3D character had 22 joints in their skeleton, each joint had a minimum of 3 channels, each channel had a keyframe for every frame of the whole sequence (1500 frames), and we had 1000 of these characters to choreograph. Memory management was a priority during the animation phase of the shot. Later, we had a major task managing the rendering, which had to be broken down into 30 individual layers. The final composite had roughly 50 separate layers totaling over 500 gigabytes of data.
VMM: Did you need to invent any new techniques, or was it a straight-forward movie to produce effects for?
All of the borrowers in this shot are bluescreen extras composited into place.
Click for a larger image
PF: From our point of view it was fairly straight forward. Our main thing in 3D was developing an effective way of blending together the motion-capture data seamlessly which we achieve through a combination of plug-in's and existing tools in Alias.The biggest innovation in the visual effects was the development of a process by which live action camera-moves on an over-size bluescreen set could be recorded, scaled and then encoded into a motion control rig on the actual size sets. This ensured continuity between the bluescreen footage of the performers playing the Borrowers and the backgrounds (shot on the actual size sets) into which they had to be composited.
One of the bonuses of the film's art direction was that the color blue was never used in any of the shots, aside from making blue-screen matting fairly simple it also meant that we were able to render all of our CGI elements against 100% blue, mattes were then created in the composite phase through the use of the Ultimatte keying software on Cineon.
VMM: If you could go back, is there anything you would have done differently or would have liked to have done again?
PF: Well, on the run-around-the-kitchen shot I would have like to liked to have been able to have spent more time getting more motion capture as I was a bit limited by the data that I had. I would also have liked to have got a better survey of the actual-size set for camera-matching purposes.On the crowd scene, if I did it again I would probably generate the shelves that the Borrowers stand on as well as the figures themselves. This would have made life a hell of a lot easier for the compositors plus it would have given me greater scope for interaction between the Borrowers and the props on the shelves, both in terms of physical movement and also in lighting.
The Borrowers will be released in the US on February 13th. The visual effects were supervised by Peter Chiang, and totaled up to around 260 shots. 2 million US dollars were spent on visual effects. The Borrowers has an official web site at www.the-borrowers.com.
All images copyright © 1998 PolyGram Entertainment.
Paul Younghusband is a digital artist and Chief Editor of Visual Magic Magazine. He lives in North-East England and can be contacted by email at paul@visualmagic.awn.com.
