Depth Cues
• What is a cue– Independent source of information about depth
(when interpreted)– Cue types
• Monocular static
• Monocular dynamic
• Binocular
• Metric, relative, ordinal
Possible Cue List
• Accomodation/
• Convergence
• Arial perspective
• Stereopsis
• Height in visual field
• Motion disparity
• Occlusion
• Relative Size
• Relative density
• Linear Perspective• Shading/shadows• Texture gradients• Kinetic depth (depth
from motion)• Dynamic occlusion
(accretion deletion)• Gravity
Range of Cue Effectiveness
Cue strength
Occlusion
Relative Size
Eye Height
h
Atmospheric Perspective
Motion Parallax
http://psych.hanover.edu/Krantz/MotionParallax/MotionParallax.html
Convergence
Known angle, inter-ocular separation,Known angle => Depth of fixation point
Accommodation/Blur1) Knowing your current focal length2) Blur gradient
Stereo Disparity
Texture GradientSize, Shape (compression), Density
Knill, 1998
Perspective
Shadows/Interreflections
Shadows
QuickTime™ and aCinepak decompressor
are needed to see this picture.
GravityAcceleration profile => Size + DepthCan affect scale of whole layout
Cue Combination
• Weighted combination (weak fusion) of estimates
• Cooperative combination– Disambiguation (cue promotion)– No indendepent estimates are possible
• Suppression (Veto)
What’s wrong?
Ron Davis Six-Ninths Blue, 1966 Ames Room
Quant. Immersion
Why did we read this?1) controlled evaluation of performance in VR2) Illustrates problems in purely empirical approach to
quantifying cue effects in VR.
3) Cue du jour: Head movements
Problems
• Shows difficulties in direct empirical approach.– Can’t test everything– Prediction? What prediction?
• Quant. Immersion? Hey, wait a minute. Did they ever measure immersion?
Horopter