Integrate Tobii Pro Glasses into Vicon Tracker

Connect a Tobii Pro Glasses 3 recording unit to the Tracker PC

To connect the Tobii recording unit to the Vicon Tracker computer, it must be able to obtain a valid IP address (IPv4 or IPv6).

To enable this, we recommend the following workflow, starting with connecting via Ethernet. Note that this method requires a valid DHCP router. (If you don't have access to a router, see Other connection methods.)

Connect via Ethernet

From the router (such as a D-Link), connect via Ethernet to:

• An Ethernet network port on the Vicon Tracker computer
• The RJ45 port on the Tobii recording unit

If you don't need to connect the Tobii Pro Glasses 3 via WiFi , you can now add the Tobii glasses into Tracker.

Connect via WiFi

1. Ensure you have successfully connected the Tobii recording unit via Ethernet, as described above.
2. Browse to http://<recording unit serial number>.local/network.html.

3. Either create a new WiFi configuration or select an existing one. To create a new configuration:

   1. Under WiFi, click Create.
   2. Set the SSID, network security type, and password, if required.
   3. Click Apply.
4. Disconnect the Ethernet cable.

Other connection methods

If you want to use an alternative way to connect the Tobii Pro (for example, if you don't have access to a router), you may find the following additional information helpful.

Connect to the Tobii 3 directly via WiFi

If you use this connection method, the Tobii Pro Glasses 3 recording unit acts as an Access Point so any device with a spare WiFi card can connect.

• SSID = <recording unit serial number> (eg, TG03B-080200013621)
• Default password = TobiiGlasses

Connect to the Tobii 3 using a direct Ethernet link

This connection method requires some configuration on the device first:

1. Connect to the Tobii via one of the methods described previously.
   • If connection is via the direct Wifi connection, go to http://192.168.75.51/network.html (assuming no other configuration has been done to change the default IP address).
   • If connection is via Ethernet, go to http://<recording unit serial number>.local
2. Do one of the following:
   • Under the wired network settings at the bottom of the page, change the profile to default-link-local and click Apply; or
   • Configure the Tobii to be a DHCP server.
3. Connect the Tobii 3 directly to the PC via Ethernet.

Add the Tobii glasses into Tracker

To add the Tobii Pro Glasses device into Vicon Tracker:

1. Ensure the Tobii recording unit is connected to the Vicon Tracker computer via Ethernet or WiFi (see Connect a Tobii recording unit to the Vicon Tracker computer).

2. Ensure that the Tobii glasses are being worn by a subject in the volume.

   (Tobii glasses connect to Vicon Tracker only when the glasses are worn: if no eye is detected, the device is gray in the System Resources tree.)

3. In the System Resources tree, right-click Devices, point to Add Digital Device and then select Add Tobii Pro Glasses 2 or Add Tobii Pro Glasses 3.

   

   With Tracker 3.9 and later, when you first create a Tobii Pro 3 or Tobii Pro 2 device, a dialog box is displayed.

   

   To continue, select from the displayed options:

   • Accept – No further dialog boxes are displayed until Tracker is restarted.
   • Accept, do not show again – No further dialog boxes are displayed until a later version of Tracker is used.
   • Cancel – No device is created and the dialog box is displayed again if you try to create a new Tobii device.

   If you select either of the Accept options, Vicon Tracker searches for the glasses on the network. When the glasses are discovered, data begins streaming in Tracker.

   This process may take some time.

4. With the Tobii Pro Glasses device selected in the System tree, in the Properties pane, ensure that in the Sampling Rate field, the required sample rate is selected.

   

5. Before capturing data, for each object, perform a calibration on each set of glasses in the same way as in the Tobii Glasses software.
   1. Instruct the subject to look at the calibration card, with the card held between 0.5 m and 1.5 m from the subject (for correct placement of the card, see the Tobii documentation).
   2. In the System Resources tree, ensure the required Tobii Pro Glasses device is selected and in the Properties pane, go to the Calibration section and click Start Calibration .

      

      Ensure the subject continues to look at the calibration card.After approximately three seconds, status information is displayed, with a success or fail status at the end of the process.
      • If calibration is successful, the Calibration Status changes to calibrated.
      • If calibration fails, see Possible calibration issues for a list of likely issues, and correct any issues that you identify.

        

      Note that, for Tobii Pro Glasses 2, data that is needed for calibration is created on the SD card and is deleted when the device is deleted. If the connection is lost, projects and participants may be left on the SD card.If no data is received for approximately one second, it is assumed that the connection has been lost and the device reverts to 'discovery' mode to try to re-connect to the device when it becomes available again.

6. The Tobii Pro Glasses 3 mocap integration kit is provided as two marker tree attachments.

   Attach the mocap integration kit by screwing it into the fittings on the frame of the glasses.

   The Vicon Tracker installer provides two VSKs for the two variants of these marker trees. If you require more objects, you can interchange the left/right trees from each of these two sets. For additional VSKs, contact Vicon Support.

7. Load the appropriate VSK. The relevant VSKs for the version of the integration kit provided in your Tobii Pro Glasses box are found in:

   C:\Program Files\Vicon\Tracker3.#\ModelTemplates

   

8. To visualize the gaze data in the Tracker workspace, with the Tobii Pro Glasses device selected in the System tree, go to the General section of the Properties pane and set the Glasses Object (left image) to the name of the object that was assigned to the glasses (right image).

   

   

   Note that specification of the Glasses object is not a requirement for receiving the data from the glasses: it is used for visualization in the Tracker 3D workspace only. Also note that if multiple Tobii Pro Glasses are in use, ensure that the objects have unique names. To do this, for each eye tracker, in the Glasses Object field, specify the subject name followed by a colon and the segment name, for example, SubjectAGlasses:TobiiGlasses and SubjectBGlasses:TobiiGlasses.

9. After you've completed these steps, notice that:
   • The eyes are displayed relative to the glasses segment at positions specified by the Left/Right Eye X,Y,Z components, and gaze direction is shown as a line from each eye to the Gaze position.
   • The eye itself also rotates to match the Left/Right Gaze value, though this may be difficult to observe.

For details of the resulting data that is reported by Tracker, see Understand output data.

Possible calibration issues

If calibration was not successful, check for these possible issues:

• Calibration card is too close (<0.5 m).
• Calibration card is too far away (>1.5 m).
• The subject is not looking at the calibration card.
• There are multiple possible calibration targets (multiple cards or objects that look like cards, or the card is visible in the displayed video that is also in view).
• The eye tracker or card moves too much during calibration.

Understand data output

Tobii Pro Glasses outputs are available for:

• Left (Right) Eye X, Y, Z position of the eye with respect to the origin of the glasses segment/scene camera and the diameter of the pupil
• Left (Right) Gaze A three-component vector specifying the direction of the gaze for the eye
• Gaze position The calculated point of focus for the combined gaze with respect to the origin of the glasses segment/scene camera