2009

nature of the position data it creates. In general, one would like to see a
"snap shot" of the performers skeletal position rather than a time-skewed
data stream. This position data is typically applied to an inverse kinematics
system, which in turn drives an animated skeleton.
See also:
Importing Motion-Capture Data on page 4576
Filtering Motion-Capture and Marker Data on page 4577
Sliding Footsteps on page 4581
Prop Bone on page 4583
Importing Motion-Capture Data
In character studio, you can import both rotation and position type
motion-capture files.
BioVision (.bvh) files contain limb and joint rotation data.
character studio marker files (.csm) contain raw marker position data
generated by a motion-capture device: markers are attached to an actor
during a motion-capture performance.
Marker files typically require some calibration. If necessary, the biped is
sized to fit the markers first, then the biped limbs are oriented to align
them to the markers. Marker files should be loaded with keys at every
frame and no footstep extraction; this is required for calibration, and also
enables the calibration controls. Calibration controls are the second row
of buttons on the Motion Capture rollout.
In character studio, the .csm marker file format supports a prop bone in
either or both hands. See
Prop Bone on page 4583.
Key reduction, track selection, footstep extraction, and clip looping are some
of the options available using the Motion Capture import filter. Key reduction
makes it easy to manipulate the biped and personalize the imported
motion-capture data. Extracting footsteps from motion-capture data prevents
inappropriate sliding feet, which are a common problem with motion-capture
data.
Typically you do not use an entire motion-capture clip as is, unless you capture
motions at a studio for your own production. You should become familiar
4576 | Chapter 17 character studio