Animation: Motionbuilder 4.0
Issue: Volume: 26 Issue: 6 (June 2003)

Animation: Motionbuilder 4.0

By George Maestri

Motionbuilder 4.0 is the latest offering from Kaydara, a company whose name is almost synonymous with motion capture. Motionbuilder is being presented as a new program but is actually a complete rebuild of Kaydara's Filmbox 3.5 animation system.

The new software uses Filmbox technology but features an interface that has been totally revamped to render it more user friendly. In addition, it has a number of new features that make it a robust character animation system that should be highly useful to anyone involved in mo-tion-creation projects, whether or not they employ motion capture.

At its heart, Motionbuilder is an animation system that can work with all types of motion—including keyframed, captured, or that imported from a variety of sources. Motionbuilder supports all the major motion-capture formats, allowing you to work with real-world motion.

This product is almost exclusively an animation tool: It does not handle modeling, special effects, or high-end rendering. Therefore, for most users, Motionbuilder works best as a companion to more traditional 3D tools.

To facilitate this complementary aspect of the program, Kaydara provides Motionbuilder's FBX file format and plug-ins for most of the major 3D packages, including Alias|Wavefront's Maya, Discreet's 3ds max, NewTek's LightWave, and Softimage. The FBX format incorporates 3D model data, texturing, skeletons, rigging, and animation data. It's probably the most powerful 3D file format in existence. I have used it to transfer scenes between packages without even involving the Motionbuilder program.

The FBX format is also available as a plug-in for Quicktime, which lets people view motion files on any system. This is a great feature for directors who need to see animation files but don't have sophisticated 3D software.

Setting up a character in Motionbuilder is straightforward. The software comes with a standard human skeleton that you can fit to your existing model. You can also build your own skeletons for other types of characters. For most characters, however, the Motionbuilder skel-eton works well, and I haven't needed to create anything else.

Motionbuilder's powerful blending tools allow for the looping and assembly of motion clips, providing precise control over each blend and blending area. The program's viewer lets users visualize the results of blends in real time.

This skeleton also facilitates the clean transfer of motion between characters. A problem common to motion capture ap-plications is that the size of a virtual character never quite matches that of the human being captured. To overcome this, Kaydara has over the years developed technology to seamlessly transfer motion between characters of varied sizes. This technology has the added benefit of allowing you to store and reuse animation from any source, including keyframed animation. For large projects, this can be an incredible time saver, as animation clips from one character can be seamlessly applied to others.

Motion creation and editing can be accomplished by using a variety of methods. Characters can be key-framed, as with any other package. The software has a nice graph editor as well as a new dope sheet.

Motionbuilder also now has a nonlinear animation editor that lets you mix combinations of animation clips or mo-tion-captured data. It can also be used with the keyframer to add motion to existing animation layers. While nonlinear animation is a feature in many packages, I found Kaydara's implementation especially powerful and easy to use. Another way to create motion is by triggering animation clips through an external device, such as a keyboard, joystick, or MIDI controller. This provides an almost computer game-like way with which to create motion interactively.

Kaydara has had a great deal of experience with real-time animation, and Motionbuilder reflects this. The program's interface and responses are fast, and previews happen in real time on any machine with a decent OpenGL card. I tested it on a dual 1.4Ghz Pentium III workstation with an Nvidia GeForce4 card, and it worked very well. This real-time feedback, combined with the terrific animation tools, makes Motionbuilder an efficient way to animate. I believe this is where animation software will be going in the future—fast, game-quality interactivity combined with easy setup and the ability to create and sculpt motion on the fly.

Facial animation in Motionbuilder can be accomplished through a variety of methods. The most straightforward of these is to use blend shapes to morph the geometry to the desired shape. This is the method used by most other 3D packages, and the principles are the same.

For users doing a lot of facial animation, Kaydara has a built-in voice recognition system. Phonemes can be connected to specific mouth shapes to get the first pass of the animation in near-real time. The animation can then be tweaked by an animator to add emotion and nuance. I found the voice recognition module to be accurate, though, like most of these systems, it tends to over-animate the face. To counteract this, it's best to reduce the keyframes once you plot the animation.

For people on a budget, Kaydara provides a personal version of Motionbuilder for only $100, which should make trying it an easy decision. For those in production, the $3495 cost of the full package may seem a bit prohibitive, but the paybacks in terms of productivity should make it well worth the price.

Kaydara has scheduled Motionbuilder 4.5 for release in the near future. The main features that will be added to this version are a new storytelling timeline, improved rendering, better usability, and enhancements in creating other types of characters, including quadrupeds. The new version also includes a Story tool, which allows users to easily edit 3D animation in combination with audio, video, and various constraints.

Since Motionbuilder is an animation-only package, those wanting to do high-end rendering and effects will need to have a major 3D modeling software package in their toolkit. However, Motionbuilder is probably the best way to animate characters on the market today.

George Maestri is a contributing editor of Computer Graphics World and president of Rubberbug, an LA-based studio specializing in character animation.


Price: $3495. Personal version: $100
Minimum System Requirements: Macintosh running OS 10.2; Windows machine running Windows 2000/XP; or Intel-based machine running Red Hat Linux 7.1; 256mb of RAM; approved OpenGL card