MotionBuilder 6 offers an intuitive interface for setting up multiple cameras and sequencing in a story timeline.

Extra Joints
If you’re working with a quadruped or biped that has more than the standard complement of joints, MotionBuilder’s TK selection widget becomes less useful, since these extra joints are not selectable through this interface. In this case, MotionBuilder creates effector handles that are visible in the perspective views, and selecting these effectors is functionally equivalent to selecting them in the selection widget.

In Maya, a TD could simply work around the limitations of the selection widget by building a new interface to control a new character type, but while MotionBuilder Pro supports Python scripting for automation, this doesn’t lend itself to the creation of entirely new interface components. While MotionBuilder’s emphasis on interface simplicity and the use of standard human and animal characters has its advantages, MotionBuilder’s lack of deep-level interface scripting makes it hard to build tools to customize the program or to handle special cases.

On the Face of It
Whether you call them morph targets, blend shapes or some other variation, MotionBuilder lets you employ facial animation poses — again, created in another application — to generate lip-synched facial animation. And the software includes a module that will analyze an audio track to automatically identify phonemes and match the facial pose to the phoneme being spoken.

Portable Motion
Remember, one of MotionBuilder’s greatest strengths is its manipulation and re-use of motion data from any number of sources. In many environments, character animations are considered unique performances that may get modified in the context of a single character in multiple scenes, but are generally used once and forgotten. But in MotionBuilder, performances are treated as simple library objects, the way most 3D applications treat textures or models. What MotionBuilder calls motions can be re-used, modified and applied to any character, and there are elegant provisions to deal with issues inherent in taking such liberties.

In a simple example, you can have open a character, say a chubby three-foot dwarf, with a rigged skeleton, but no animation, along with a figure of a lanky seven-foot basketball player animated with motion capture. You can then apply the motion of the basketball player to the dwarf’s skeleton. In most animation systems, this would be an exercise in futility. As the basketball player walks, his arms swing close by his narrow waist, but on a dwarf, the same joint angles cause his arms to swing through the curvy sides of his belly. MotionBuilder solves the problem with its unique animation layers. These let you create keyframe animation that is seamlessly blended with the animation layers underneath. In the case of the ball player and the dwarf, you create a new layer onto which you keyframe new positions for the dwarf’s arms and hands while he walks. The motion curves for the joints of the arms are blended, realtime, with the motion curves of the underlying MoCap data. You could then add a third layer of animation, onto which you might keyframe, say, the dwarf’s jump carrying him 15 feet into the air instead of five, and this curve, too, will be blended into the mix. This solution to a previously insurmountable animation problem takes mere minutes and, in my experience, works flawlessly

Similarly, it’s easy to re-use animation in other ways. For example, you might import a walk cycle motion and apply it to a character, and want to follow it up with a jump. If your motion capture or animation hasn’t been carefully planned for this sequence, there’s a 50% chance that the jump motion will, literally, get off on the wrong foot. In MotionBuilder, you can fix this problem with a single mouse click that mirrors the relative positions of all of the joints, so that the right foot will now be forward and so on. And when you combine two motion clips, it’s easy to blend one clip into the other, by translating an entire motion sequence in space, and creating a soft transition between the two sequences by blending their ends together.

This release of MotionBuilder also introduces multi-referential animation, meaning that you can change an object’s point of reference that’s used as the basis for its motion. For example, you might have an animation of a character running and jumping, but when he lands and tumbles, you want him to be on the roof of a moving truck. MotionBuilder lets you effectively add the translation of the truck to the character’s position, so that this all comes off without a hitch.

In busy production environments (meaning all but a few), the capability to re-use animation data is a lifesaver. If you’re efficient at organizing and archiving your animations, you will quickly amass a library of useful data that will practically free animators from ever having to create repetitive animation sequences again.