Issue: Volume: 24 Issue: 6 (June 2001)

Active-Optical Mocap from Ascension

ReActor's active-optical technology is a departure for Ascension, which has traditionally developed magnetic-based systems. (The ReActor technology was recently acquired from a UK-based firm.) It is also a departure from the passive-optical mocap more commonly seen in the market in which send-and-receive roles are reversed-the performer's markers pick up signals from surrounding hardware. Active-optical technology results in cleaner data, according to the company, because the 480 cameras all but prevent occlusions. In addition, the ReActor system is able to recognize individual markers and can therefore, intelligently "catch up" the data if a marker does happen to be temporarily occluded.

Additional features include a relatively easy setup-the sensor bars snap together, and calibration is not required-and the ability to operate in natural light. ReActor supports Discreet's 3ds max and Kaydara's Filmbox directly. Import and export capability to most additional 3D animation packages is available through Filmbox.

According to Greg Erdmann, technical sales manager for Ascension, future plans for ReActor include doubling the number of performers to be tracked, and both increasing and decreasing the size of the motion-capture area. A lower height, for example, is desirable "in countries like Japan, where real estate is at a premium," says Erdmann.

A system with a 12-bar sensor rig, PC and software, one motion-capture suit with 30 markers, and a battery belt pack costs $74,990. (Ascension Technology Corp.; -JD