Re: Cardboarding

[P3D Larry Berlin <lberlin@xxxxxxxxx>]

>John B. writes:
>>"...I personally reserve the term 'cardboarding' for loss of depth 
>>perception due to lack of system resolution."

>William Carter writes:
>It is my belief, and contention, that 'card boarding' is due to retinal 
>rivalry. A rivalry caused by one frames view not sharing edge elements 
>from the other frames view. 

I feel that it applies to any 3D situation where it is present. It can be
due to low resolution but I've seen it in situations that I considered to be
high resolution too. It has to do with a situation where there is sufficient
parallax to determine the relative placement of various subjects within the
scene, but insufficient parallax visible to see roundness or relative depth
of each individual subject.

It primarily relates to a lack of relative parallax which can be caused by
too great a distance from the subject or too narrow a displacement angle of
the two views, or a lack of overall resloution. You are likely to see a lot
of this if you are using a fixed base stereo camera for subjects farther
away than 10' or 15'. If it's a group of people, you may be able to easily
see each person at relative distances but not see much in the way of
roundness for each person. By cardboarding I don't mean that the objects are
perfectly flat, just that they are quite flat relative to reality and/or the
rest of the scene.

Note that you can place identical high resolution images in a side by side
viewer and see the apparently flat image at a stereo depth. Flatness is due
to the identical views which have NO parallax. The angle is more a factor in
apparent flatness than resolution though resolution can affect how much of
the existing depth cues are visible.

Larry Berlin

Email: lberlin@xxxxxxxxx
http://www.sonic.net/~lberlin/


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