what is “device center”

[fle]

tobii_get_track_box()
Function:Retrieves 3d coordinates of the track box frustum, given in millimeters from the device center.
Syntax:#include <tobii/tobii.h>
tobii_error_t tobii_get_track_box( tobii_device_t* device, tobii_track_box_t* track_box );
Remarks:The track box is a volume in front of the tracker within which the user can be tracked.

What are mentioned above are from API.I want to know if “device center” referring to the eye tracker or the center of the screen？

[Denny [Tobii]]

Hi @fle,

The device center is a coordinate in 3d-space inside the eye tracker. From application development perspective, it’s best just to assume its a point on the eye tracker close to the center (in practice). Since it can very between tracker families, don’t see this as a well defined point. Internally we use it in our device calibration applications.

On Tobii Pro site, there is a very good overview of the different coordinate systems, please have a look there http://developer.tobiipro.com/commonconcepts/coordinatesystems.html

You see the track-box frustrum there, and now it narrows down towards the eye tracker device.

[Author]

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