Eye tracking: Difference between revisions

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Now rotate your head and keep looking at the same spot.  
Now rotate your head and keep looking at the same spot.  
Your pupils are moving from left to right, the place it should detect does not move at all.
Your pupils are moving from left to right within your eye sockets -- yet the place it should detect does not move at all.
 
From ''just'' the image of the pupil in the eye, you would not get a halfway decent direction.
 
We can fix that by clamping your head in place, except a lot of people will not like you for that.
 
Another fix to this is to also track the cornea.
 
Corneal-reflection-style eye tracking (there are others) adds a reference.
That reference is the back of the eye. It is also free to move but, being (roughly) spherical,
whatever the backmost part of the eye is (which is the part that will reflect),
the place of most reflection will barely move when the eye looks around,
so it acts as an anchor.
 
This definitely still has limitations, but is also a good step less janky than just pupil.


From ''just'' the image of the pupil in the eye, you would not get a halfway decent direction
unless we clamp some heads in place.




"Can't you add, I dunno, 3D head tracking?"
"Can't you add, I dunno, 3D head tracking?"


Yes, and that does help, but also adds assumptions to the whole, as well as another limited-accuracy thing .
Yes, and that can help, but at the same time also adds assumptions to the whole, as well as another limited-accuracy thing .
 


The corneal reflection style eye tracking adds a reference that is also free to move - the back of the eye.


This definitely still has limitations, but is





Revision as of 15:48, 29 April 2024