Graphics Reference
In-Depth Information
(a)
(b)
Figure 7.4.
(a) A visible-spectrum image of markers on a performer. (b) An aligned infrared
image, showing that the retro-reflective markers appear as extremely bright dots on a dark
background.
(a)
(b)
(c)
Figure 7.5.
An example of marker placement for motion capture. This configuration uses forty-
five markers.
The performer's motion capture suit is typically outfitted with between thirty and
fifty markers. Motion capture technicians use principles from biomechanics to care-
fully and repeatably place markers on the performer's joints to give the most useful
information about the motion of his or her underlying skeleton. For this reason,
the motion capture suit must be tight-fitting, and the markers placed so that they
don't slide around the joints. In some cases, markers are directly attached to the
skin. Figure
7.5
illustrates a standard configuration for marker placement, designed
