The 3D illision

Biophysics of the 3D illusion
Seeing
The eye as an imaging system
Vitreous
humor
Macula
Aqueous humor
Crystalline
Ciliary muscle
Figure courtesy of the National Institute of Health
Accommodation and Vergence
Lensmaker’s Formula
1 1 1
= +
f u v
Lens
focal point
Object
Optical axis
f
v
u
Accommodation and Vergence
Lensmaker’s Formula
1 1 1
= +
f u v
focal point
Object
Optical axis
f
v
u
The Retina – Light Detection
• 125 million light
sensitive cells
• CONES
– sense colour
• RODS
– more sensitive to
light
– NO colour sensation
Image of the Retina showing cones (green),
rods (yellow). STEVE GSCHMEISSNER / SCIENCE
PHOTO LIBRARY
The Colour Wheel
R
M
Y
G
B
C
Afterimages
Depth Perception
Occlusion
Carte Blanche, René Magritte (1965)
Size consistency
• Familiar objects appear the same size
• But the brain can be tricked!
Ames Room
from “The computer
that ate hollywood”
Perspective
A painting by pre renaissance artist
Cimabue
A painting by Renaissance artist
Raphael
Motion Parallax
A train journey
in Hokkaido, Japan
The effect of ‘wiggle’
Image of the sun from Nasa’s STEREO solar observatory
Binocular Cues
• Each eye sees a slightly different view of the
world
• Disparity (pixel-by-pixel differences) of these
images gives depth cue – Random dot autostereograms
Random dot Autostereograms
3D Projection – Color schemes
• Anaglyphs
Menger sponger anaglyph by David C Pearson
3D Projection with Linear Polarizers
From the 3D Zone: Its Past & Its Future by Ray Zone
3D Projection – Circularly Polarized Scheme
Figure from Optics by Hecht