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The first two values in step 4 can be seen as the depth and height offset between the optical center of the eye tracker, i.e. the point inside the device where the sensor(s) are located, and the top-front edge of the eye tracker, i.e. the edge you used to calculate the screen depth and height offset in step 3.
These two values only depend on how the eye tracker is constructed, so we have provided default values for the eye trackers currently supported by the Gaze SDK:
– Tobii EyeX Controller: 10.3 mm and 10 mm respectively
– Tobii REX: 9.5 mm and 14 mm respectively
As discussed earlier in this thread, the Tobii REX values are also applicable for other eye trackers with the same form factor, such as X2-30 and PCEye Go.
The mounting angle is the angle between the screen plane and the plane parallel to the eye tracker front surface. If you use the standard mounting brackets, this angle is 20 degrees for all supported eye trackers. If you have your own custom mounting, you need to calculate this angle yourself with a tool of choice.
I’m looking forward to the day when all eye trackers are built into the screens, so this kind of configuration can be done by hardware manufacturers and not software developers or end users. Until then, if you’re not using the standard screen configuration provided by the EyeX Engine, I wish you luck!