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Martin Konopka edited this page Apr 23, 2018 · 3 revisions

GazeData

Data structure containing raw gaze data from eye tracker.

  • trackerTicks : long number - Eye tracker timestamp ticks of the current sample.
  • validity : GazeDataValidity - validity code of the eyes tracked by the tracker.
  • leftEye : EyeGazeData - gaze data for the left eye.
  • rightEye : EyeGazeData - gaze data for the right eye.
  • timestamp : DateTime - local timestamp when the data was received from the eye tracker.

EyeGazeData

Data structure describing one eye in GazeData object.

  • validity : EyeGazeDataValidity - validity of this eye.
  • gazePoint2D : Point2D - normalized 2D coordinates of the gaze on the screen.
  • gazePoint3D : Point3D - eye gaze point on the calibration plane given in millimeters (User Coordinate System, see Tobii Pro docs - Coordinate system).
  • eyePosition3D : Point3D - position of the eye in 3D space given in User Coordinate System.
  • eyePosition3DRelative: Point3D - position of the eye in 3D space relative to the track box given in the Track Box Coordinate System (see Tobii Pro docs - Coordinate system).
  • pupilDiameter : double - estimated diameter of the eye pupil in millimeters (see Tobii Pro docs - Pupil diameter).

GazeDataValidity

Enumerated value of valid eyes tracked by the eye tracker, see Tobii Pro docs - Validity codes. Only samples with value of Both, Left or Right should be used for data analysis. All possible values:

  • None
  • Both
  • Left
  • Right
  • ProbablyLeft
  • UnknownWhichOne
  • ProbablyRight

EyeGazeDataValidity

Enumerated value of single eye data validity. Only samples with value of Valid should be used for data analysis. GazeDataValidity value is combination of these validity codes for both eyes. All possible values:

  • Invalid
  • Valid
  • Probably
  • Unknown

EyeMovement

Data structure containing data of an eye movement - fixation, saccade or unknown movement. Each movement sample contains single eye data samples belonging to the movement and average sample.

  • samples : EyeVelocity[] - array of data samples belonging to the movement with velocities.
  • startTime : TimeSpan - start time of the eye movement.
  • startTimeTrackerTicks : long - start time in the tracker ticks.
  • endTime : TimeSpan - end time of the eye movement.
  • endTrackerTicks : long - end time in the tracker ticks.
  • duration : TimeSpan - duration of the eye movement.
  • position : Point2D - average coordinates of the gaze position on the screen.
  • averageSample : SingleEyeGazeData - average data sample of this movement.
  • movementType : EyeMovementType - one of the following values:
    • Fixation - movement is a fixation.
    • Saccade - movement is a saccade, position and averageSample contain irrelevant information.
    • Unknown - samples are invalid or the fixation was very short, e.g., invalid samples due to blinks.

SingleEyeGazeData

Similar to the EyeGazeData, contains gaze data about the single eye, but also contains trackerTicks and timestamp fields.

EyeVelocity

Contains measured velocity of the eye single eye.

  • velocity : double - measured velocity of the eye in deg/s.
  • eyeGazeData : SingleEyeGazeData object.

Examples

GazeData

{
    "TrackerTicks": 1520491769077825,
    "Validity": "Both",
    "LeftEye": {
        "Validity": "Valid",
        "GazePoint2D": {
            "X": 0.46933363141852169,
            "Y": 0.51498941371824
        },
        "GazePoint3D": {
            "X": -16.718640160093628,
            "Y": 163.48952878874729,
            "Z": 42.647255706260921
        },
        "EyePosition3D": {
            "X": -45.379814880740469,
            "Y": -3.4555283009722189,
            "Z": 719.08776186704858
        },
        "EyePosition3DRelative": {
            "X": 0.592995630632231,
            "Y": 0.51050877960119578,
            "Z": 0.89695922851547039
        },
        "PupilDiameter": 5.102020263671875
    },
    "RightEye": {
        "Validity": "Valid",
        "GazePoint2D": {
            "X": 0.46317361098044785,
            "Y": 0.39192965301344884
        },
        "GazePoint3D": {
            "X": -19.9666710966535,
            "Y": 201.59785098340171,
            "Z": 56.517628984696557
        },
        "EyePosition3D": {
            "X": 13.621915290749939,
            "Y": -2.1574217305044385,
            "Z": 717.62854757687751
        },
        "EyePosition3DRelative": {
            "X": 0.47044326728382657,
            "Y": 0.509012008807531,
            "Z": 0.89209513346349922
        },
        "PupilDiameter": 4.93511962890625
    },
    "TimeStamp": "2018-03-08T08:18:03.2678927+01:00"
}

EyeMovement

{
    "Samples": [
        {
            "Velocity": 22.920168142086538,
            "EyeGazeData": {
                "TrackerTicks": 1520516990797623,
                "Timestamp": "15:10:02.8110203",
                "Validity": "Valid",
                "GazePoint2D": {
                    "X": 0.49453242795080238,
                    "Y": 0.45397839568698339
                },
                "GazePoint3D": {
                    "X": -1.7683422177170882,
                    "Y": 181.01195183044325,
                    "Z": 49.024677921135066
                },
                "EyePosition3D": {
                    "X": -61.361474077682196,
                    "Y": 74.2998112986488,
                    "Z": 475.93469848863481
                },
                "EyePosition3DRelative": {
                    "X": 0.70613610433811547,
                    "Y": 0.2050880884143029,
                    "Z": 0.0864489953195856
                },
                "PupilDiameter": 6.1072311401367188
            }
        },
        ... other EyeVelocity samples
    ],
    "StartTime": "15:10:02.8009586",
    "StartTrackerTicks": 1520516990789105,
    "EndTime": "15:10:03.1439721",
    "EndTrackerTicks": 1520516991136178,
    "Duration": "00:00:00.3430135",
    "Position": {
        "X": 0.50614810577243186,
        "Y": 0.45700155159782729
    },
    "AverageSample": {
        "TrackerTicks": 1520516990966991,
        "Timestamp": "15:10:02.9781278",
        "Validity": "Valid",
        "GazePoint2D": {
            "X": 0.50614810577243186,
            "Y": 0.45700155159782729
        },
        "GazePoint3D": {
            "X": 4.3019877805214364,
            "Y": 180.08335230760596,
            "Z": 48.686694834297519
        },
        "EyePosition3D": {
            "X": -63.391866833864512,
            "Y": 77.018571985377221,
            "Z": 485.32904569036054
        },
        "EyePosition3DRelative": {
            "X": 0.70656203404287643,
            "Y": 0.20036576206055706,
            "Z": 0.11776349136098156
        },
        "PupilDiameter": 6.05218505859375
    },
    "MovementType": "Fixation"
}
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