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DTrack2
frontend software
(’ wand residual ’) and the maximum deviation (’ wand range ’) of wand length during the
calibration process. The value ’ Used Frames ’ represents the percentage of valid (i.e.,
used for room calibration) data for each camera.
Try to achieve a low ’ mean wand residual ’ up to 1 mm for VR installations while having
high values for ’ Used Frames ’. The number of ’ Used Frames ’ should be greater than 70%
for each camera. Values under 50% indicate poor room calibration quality. The param-
eters ’
Residual ’ for each camera and the ’ wand range ’ depend on the system geometry
and give additional information about the quality of calibration. Please call ART for further
information.
Figure 8.25: Room calibration result
The room calibration is confirmed (i.e., the data are stored) by pressing the button OK .
Z
Please note that percentages of more than 70% may not be reached in
large and complicated measurement volumes.
8.6.3.3 Room re-calibration
All camera setups may change after a certain operation time; if e.g. movement of single
cameras due to mechanical instabilities cannot be ruled out or thermal drifts occur it is
necessary to perform room calibrations periodically.
DTrack2 provides a simplified room
calibration to revise an existing room calibration without need of an calibration angle,
called room
re-calibration .
This means no calibration angle has to be present in the measurement volume; only
the wand has to be moved the same way as for a standard room calibration. The main
advantage of a room re-calibration is that
DTrack2 preserves the origin of your coordinate
system and therefore, the orientation of the coordinate system as well.
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