Game Development Reference
In-Depth Information
P
P
I d
I g
Screen
Left eye
Right eye
Head movement
Figure 13.6 Pseudoscopic movements when the observer moves the non-tracked head
P
P
I g
I d
Screen
Right eye
Left eye
Head movement
Figure 13.7 Pseudoscopic movements when the observer moves the non-tracked head
The eyes of the observer translate to the right and he sees point P move to the left
to point P , because the points I d and I g are fixed. This phenomenon is rarely noticeable
because the observer is often sitting, which means that the lateral translation of the
head will be too low to sense these incorrect movements. A similar pattern helps to
understand that if the observer moves back or forward facing the screen, there is
stretching or shortening of the depth perceived (Figure 13.7).
This phenomenon implies that theoretically there is only one distance to the screen
(the orthostereoscopic distance) that is not likely to distort objects, depending on the
axis of the depth. In practice, the brain tolerates a distortion margin between the
dimension in depth and the dimensions parallel to the screen. If the observer is likely
to move his head and if you want perfect vision, it is recommended to determine the
position of the head owing to a spatial localisation sensor: suppliers recommend this
device, mainly on immersive workbenches and in visiocubes. To conclude, except in
 
Search Nedrilad ::




Custom Search