[IGSTK-Users] (no subject)

[Steve Fallows]

I have integrated the Ascension 3DG Tracker classes in IGSTK into the
NeedleBiopsy example and it is tracking. However the Z axis is reversed
from what we would like, as the data comes from the tracker. The existing
example code for Aurora/Polaris trackers provides a Z flip option, so I
tried to use that like this:

        igstk::Transform::VersorType rotation;
        rotation.Set(1.0, 0.0, 0.0, 0.0);
        igstk::Transform toolCalibrationTransform;
        toolCalibrationTransform.SetRotation(rotation, 0.1,
igstk::TimeStamp::GetLongestPossibleTime());
        tool->SetCalibrationTransform(toolCalibrationTransform);

       tool is a Ascension3DGTrackerTool::Pointer.

However there was no change to the direction of Z motion. I guess this is
due to one of two things:

1. My versor is wrong. I don't know much about them (yet). It seems the two
documents about Quaternions on the ITK site are gone. (These links
   seem to be dead: http://www.itk.org/CourseWare/Training/QuaternionsI.pdf
http://www.itk.org/CourseWare/Training/QuaternionsII.pdf<http://www.itk.org/CourseWare/Training/QuaternionsI.pdf>

2. Since the Ascension device doesn't need any calibration, the calibration
transform is ignored.

Can anyone point me in the right direction to flip the Z axis somehow?

Thanks
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