Art Flystick3, Руководство пользователя системы, Страница: 176 / 275

8
DTrack2
frontend software
to confirm the resulting transformation and to close the dialogue. Pressing Apply accepts
the current changes and leaves the dialogue open. Discard all changes by pressing
Cancel .
8.6.5 Body calibration
8.6.5.1 Body calibration overview
The process of teaching a target’s geometry to the tracking system is called body calibra-
tion. For a body calibration, the target (= rigid body) to be calibrated has to be in the field
of view of the IR cameras.
The body can be moved during body calibration, always considering that the cameras
should see each marker of the body at the best.
If the body is not moved during the body calibration it should be considered that each
marker of the target has to be seen by at least two cameras and should be seen by as
many cameras as possible. If two markers, seen from one camera’s point of view, are
merging to one reflection, body calibration may be affected. These "merging marker situ-
ations" should be avoided during body calibration, i.e. the target should be oriented in a
way that reduces merging markers to a minimum. The target orientation can be checked
using
DTrack2 ’s Monitor 2DOF display , which is opened automatically in the background
after starting the body calibration. The following figure 8.30 on page 176 shows a rigid
body with five markers that are all correctly seen by the IR camera.
Figure 8.30: Recognized target in DTrack2 Monitor 2DOF display
Furthermore, the absence of any additional markers in the measurement volume has to
be ensured for body calibration. If additional markers that are not part of the target to be
calibrated are in the field of view of the IR cameras during body calibration, these mark-
ers will be assigned to the target. That means, the target is not correctly calibrated and,
therefore, tracking problems may occur.
176