Ask your average animator on the street what he or she thinks of magnetic motion capture, and the answer will be either skeptical or enthusiastic. The skeptical response is often heard from animators using older-generation magnetic trackers. Back then, animators had to be computer scientists as well as creative geniuses. They had to be system integrators pulling all the pieces together, mapping and remapping the motion-capture stage to control metal distortion, developing their own software links to animation software packages. The enthusiastic response most likely comes from animators familiar with recent hardware and software improvements that let them focus on creative content. The latest DC magnetic motion trackers, for instance, lessen the old metal-distortion headaches, and powerful new software "plug-ins" readily handle noise and data "clean-up" issues.

On top of these improvements, Ascension Technology has come out with an even more potent antidote to magnetic motion-capture skepticism. A new turn-key system combines Ascension's MotionStar^® or MotionStar Wireless^® motion trackers with an Intergraph TDZ workstation and Kaydara FiLMBOX software-in one package running on an NT operating system. Going with the TDZ reduces entry costs. Using FiLMBOX means animators can integrate motion-capture files with major animation software, have advanced editing features to modify data files, and simultaneously handle both distortion and noise problems.

When the concept for this turn-key system was developed, Ascension had in mind small production houses, game developers and start-ups-those currently keyframing on a PC, but ready to move up a notch to a quicker, more versatile process with more lifelike results. Because this next generation of animators is still in a start-up mode, most likely they have neither the budget for an in-house technician to handle integration or distortion problems, nor the budget for a high-end, SGI-based system. Even many high-end production facilities are migrating to NT and looking to spend less, stay within budget constraints, and get the same processing power. This is where the NT, integrated system is finding its niche.

Occasionally, motion capture performance locations are such that electromagnetic or metal interference is probable. In those cases, Ascension makes site recommendations. These are often as simple as moving the tracking equipment away from a conduit or constructing a wooden platform to elevate performers' feet above a steel-rebar floor. (All MotionStar Wireless units come with on-site installation and training.) Kaydara offers a one-time map and compensation procedure for correcting distortions if the site has an unusual source of troubling metallic interference. Once the data is captured, FiLMBOX's arsenal of noise controlling filters can be deployed to smooth the data. In each instance, production delays due to interference are minimized.

The turn-key package can be bought starting at a fraction of the cost of an optical system. Price varies depending on how many FiILMBOX modules, MotionStar sensors, etc. the buyer needs and which workstation the buyer selects.

Another innovation is the CyberSuit^TM, a black nylon unitard worn by the motion capture performer. The CyberSuit comes with 15 snap-in sensor holders and channeled tubing to hold and guide sensor cables. Along with being functional, the suit brings an aesthetic appeal to the production. It was designed by Muriel Stockdale, an independent New York costume designer who has countless aliens, Muppets, and Broadway productions to her credit.

While this seems to imply a multitude of bells and whistles complicating the package, the reverse is true. The three basic components-the MotionStar, FiLMBOX and the Intergraph-all of which can be purchased separately, are all that is needed for a fully functional motion capture production system.

MotionStar tracks position and orientation through a pulsed DC magnetic field emitted by an extended range transmitter. It captures full six degrees-of-freedom motions without line-of sight restrictions. Up to 90 sensors (for multiple characters) can be tracked simultaneously with the wired unit, up to 20 sensors per performer with the wireless, which handles up to four performers at once. The wireless unit has the advantage of letting performers twist, flip or pirouette without tangling cables. Independent processors for each sensor means quicker measurement rates than multiplexed systems: data update rates for either unit are about 100 measurements per second.

FiLMBOX's Capture Reality module processes the MotionStar data in real-time using an advanced suite of motion capture, animation and interactive rendering tools designed from the start for motion capture. While FiLMBOX can export motion capture data to all major 3D animation packages, the newest FiLMBOX version assumes more of the job itself. Size calibration can be done quickly in an initial pose, so a six-foot performer can generate movement for a two-inch animated centipede without constant recalibration. Its HumanIK feature lets animators automatically attach MotionStar data to skeletons, which saves time connecting the data to characters' joints. Motion Sculpting with control curves makes applying offsets to captured animation fairly easy and provides a secondary level of animation control.

This is the first time a turn-key motion capture system is being offered by the tracking manufacturer. Prior to this, several companies purchased the components piecemeal or through Kaydara. Many game developers, however, are now recognizing the flexibility and capability of an NT-based mocap animation system and the advantages of owning their own.

Contact:
Greg Erdmann
Ascension Technology Corporation
Tel: 802-893-6657  Fax: 802-893-6659
e-mail: greg@ascension-tech.com
http://www.ascension-tech.com