P3D Re: Love those violations?

["Greg Wageman" <gjw@xxxxxxxxxx>]

From: Paul Talbot <ptww@xxxxxxxxx>


>The concepts of "window violation" and "objects coming through the
>window" ("TTW") are frequently misunderstood and/or confused with
>each other.  A window violation is (generally) an ERROR.  TTW is
>an EFFECT.  You might love it or hate it, or somewhere in between.
>Whether to use TTW or not is largely an aesthetic question for
>each particular image.


Paul speaks truth. :-)

The problem with "window violation"; that is, when an object appears to
come through, yet at the same time be "cut off" by the stereo window, is
that it causes a depth-cue conflict.  The depth cue produced by
binocular disparity indicates to our perception that the object should
be projecting in front of the apparent position of the window in
3-space.  However, the cue of occlusion suggests that since the object
is being obscured by the window boundary, it must therefore be behind
the window.  The brain tries to reconcile these clashing cues, and what
usually results is the collapse of the 3D illusion for the object in
question, and possibly for the image as a whole depending on how much of
the image the violating object represents.  Thus this situation is
considered best generally avoided. :-)

Usually this is regarded as a compositional or mounting error, depending
on severity.  "Or", because if not extreme, it can be adjusted for in
mounting by shifting the window forward to eliminate the apparent
"violation".  If the object projects significantly forward of the
window, however, it is a compositional error to have it partly obscured
by the window as well.

     -Greg W. (gjw@xxxxxxxxxx)





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