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