Overview - 3D Postproduction: Stereoscopic Workflows and Techniques - page 18

1.4 The 3D Illusion
The key aspect of 3D, of course, is the sense of “depth” it generates for the
viewer. Depth , as used in this topic, describes the illusion of physical space or
distance between elements in scene. Elements or areas of interest (a person
or object, for example) in scenes appear at the screen, behind the screen, or
in front of the screen. Simply put, image pairs generate 3D frames and 3D
frames generate the 3D illusion.
1.4.1 Binocular Vision
How do 3D frames generate the illusion of depth? Presenting 3D frames
to the human visual system simulates a fundamental aspect of everyday
human experience: binocular vision . Binocular vision is the experience most
people have when seeing with two eyes. (Research on what percentage of
people can experience 3D depth and to what degree is ongoing and outside
the scope of this topic. Remember that a small percentage of your potential
viewers may not experience 3D depth at all.)
3D is not equivalent to binocular vision. The key word here is “simulate.”
Simply put, the purpose of 3D post is to deliver a convincing illusion of
depth by delivering 3D frames that simulate the sensation of binocular vision
in viewers. The entire technical work of 3D postproduction is in service to
this illusion and to the creative possibilities it allows.
“The whole point of what we do is to create a retinal disparity
in the viewer that mimics their understanding of 3D space and
reminds them of their internal model of 3D space. If you can do
then you can manipulate people's reactions. Pushing these limits
is what 3D is all about.”
—Ray Hannisian
1.5 Core Conditions for 3D
3D postproduction maintains time and space relationships between two
2D representations from the instant of image capture to the i nal display of
the imagery to the viewer or audience. 2D motion imagery requires certain
core conditions to tell a convincing visual story. These conditions include
spatial factors such as framing or post moves as well as temporal factors