Process and export Tobii gaze vector data

Reprocessing of gaze vector data

The Gaze vector data can be reprocessed in a file, both in reprocessing and batch processing. This is useful if you need to update the gaze vector data because of changed 6DOF data.

If you have changed the 6DOF data then you need to reprocess the Gaze vector data to update it. Follow these steps to reprocess it.

  1. Click on Reprocess on the Capture menu.
  2. Then select Calculate gaze vectordata in the Processing steps.
    • If you need to change the rigid body that is associated with the gaze vector, then go to the Gaze vector page and double click on the gaze vector in the list.
  3. Click OK in the File reprocessing dialog.

Export formats for gaze and eye tracker data

The gaze vector and eye tracker data can then be exported and analyzed in external programs. You can either export it to TSV or MAT files.

TSV

To export the eye tracker data select the data type Eye tracker in the TSV export options. The gaze vector and eye tracker data will be exported in separate files, for example *_g_1.tsv and *_g_2.tsv with gaze vector data for the left and right eye, respectively. The data included in the gaze vector export (_g.tsv) is:

  • GAZE_VECTOR_NAME
    The name of the gaze vector.

  • NO_OF_SAMPLES
    The number of samples in the gaze vector data.

  • FREQUENCY
    The frequency of the gaze vector data.

  • TIME_STAMP
    Date and time when the motion capture file was made. The date and time is followed by a tab character and then the timestamp in seconds from when the computer was started.

  • START_OFFSET
    The offset time for the first gaze vector frame. It is needed since you may not always cut the measurement range at the start of gaze vector frame. Reduce the start time of the gaze vector data with the offset so that it actually starts before the marker data.

  • HW_SYNC
    Indicates if hardware sync was used (value: YES) for the eye tracker data or not (value: NO).

  • FILTER
    Indicates if the gaze vector data was filtered (value: YES) or not (value: NO).

  • Gaze vector data
    Columns with the gaze vector data in the following order: X Pos, Y Pos, Z Pos, X Vec, Y Vec, Z Vec.

For Tobii Pro Glasses 2 devices, the eye tracker data is exported as *_e.tsv files. The data included in the eye tracker data export (_e.tsv) is:

  • EYE_TRACKER_NAME
    The name of the eye tracker device.

  • NO_OF_SAMPLES
    The number of samples in the eye tracker data.

  • FREQUENCY
    The frequency of the eye tracker data.

  • TIME_STAMP
    Date and time when the motion capture file was made. The date and time is followed by a tab character and then the timestamp in seconds from when the computer was started.

  • START_OFFSET
    The offset time for the first eye tracker data frame.

  • HW_SYNC
    Indicates if hardware sync was used (value: YES) for the eye tracker data or not (value: NO).

  • Pupil diameter data
    Columns with the gaze vector data in the following order: LEFT_PUPIL_DIAMETER, RIGHT_PUPIL_DIAMETER.

For Tobii Pro Glasses 3 devices, the eye tracker data is exported as analog data, see chapter Analog data (_a.tsv).

MAT

To export the eye tracker data select the Eye tracker option for the MATLAB file export. The struct array of the MAT file then includes the following data:

  • GazeVector
    The struct array consists of the following elements for each eye. For example write GazeVector(1).GazeVectorName to access the name for the left eye.

    • GazeVectorName
      The name of the gaze vector.

    • NrOfSamples
      The number of samples in the gaze vector data.

    • StartOffset
      The offset time for the first gaze vector frame. It is needed since you may not always cut the measurement range at the start of gaze vector frame. Reduce the start time of the gaze vector data with the offset so that it actually starts before the marker data.

    • Frequency
      The frequency of the gaze vector data.

    • HWSync
      Indicates if hardware sync was used for the eye tracker data or not. The values can be 0 (no hardware sync) or 1 (hardware sync).

    • Filter
      Indicates if the gaze vector data was filtered or not. The values can be 0 (not filtered) or 1 (filtered).

    • GazeVector
      Array with the gaze vector data in the following order: X Pos, Y Pos, Z Pos, X Vec, Y Vec, Z Vec.

  • EyeTracker
    Struct array with the following eye tracker data.

    • EyeTrackerName
      The name of the eye tracker device.

    • NrOfSamples
      The number of samples of eye tracker data.

    • StartOffset
      The offset time for the first eye tracker data frame.

    • Frequency
      The frequency of the eye tracker data.

    • HWSync
      Indicates if hardware sync was used for the eye tracker data or not. The values can be 0 (no hardware sync) or 1 (hardware sync).

    • EyeTracker
      Array with the pupil diameter data in mm in the following order: left pupil, right pupil.

For Tobii Pro Glasses 3 devices the eye tracker data is exported as analog data, see chapter MAT file format.