I should also add that I’ve tried the setdisplayarea utility included in the Gaze SDK but am still not having luck getting the calibration to go through. What’s odd is that in my software, if I look at my on-screen targets, gaze tracking appears to still work because I’m seeing live data come through, so it’s surprising that the calibration still fails in this case.
I see a few related threads from about a year that seem to suggest that this setup should be possible (as long as the tracker is close to the user, the user), but no reports of anyone actually having success:
http://developer.tobii.com/community/forums/topic/calibrating-a-rex-mounted-forward-of-a-large-screen/
http://developer.tobii.com/community/forums/topic/tracking-on-large-screen-user-relatively-close-to-screen/
http://developer.tobii.com/community/forums/topic/how-to-use-the-eye-tracker-for-a-large-screen/