Re: *Inner parallax*

[T3D Larry Berlin <lberlin@xxxxxxxxx>]

Bill Stratemeyer  writes:
>  I just finished a test of modifying deviation only for 
>objects in a stereo pair. 
>
>  This is what I did.  First I rendered a ray traced stereo
>pair for cross eyed viewing.  In The left image the near
>object a dolphin has .25" deviation difference as compared 
>to the same object in the right image.(5"x4" image size) 
>  Next I masked the left images near object and cut & repasted 
>it to a new position with .0" deviation.  Then I cloned in 
>missing back ground information (Photoshop allows you to clone
>from one image to another).
>  When viewing and comparing the 2 sets of stereo pairs the
>only difference appears to be the depth of the dolphin with no 
>distortion (Bulge or stretch)and the object size seems to be
>the same as in the unmodified pair.
>  I would have expected this to have made the dolphin a hyper view 
>object (smaller)?  Maybe I need to redo this with an exaggerated
>amount of parallax in the near object to see any distortion or
>change of apparent object size?
>  Would the results be different when seen in a viewer or in
>projection?

So far you're observing what I expected from my own work in the computer. As
you exaggerate the parallax of the object, the mind will interpret the depth
placement and parallax structure in relation to what else is in the image.
It will be interesting to try this with images intended for projection and
see what if any noticable effects may appear. One thing to keep in mind is
that if a close up object is being moved back in the scene, you may be
shrinking its size as well as placing it deeper. The shrinking step
proportionally reduces the *internal* parallax of the object. BTW, are there
existing terms for these different types of parallax? (now that they can be
used as separate but related entities)

Larry Berlin


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