Depth Cues What is a cue Independent source

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 a h

Atmospheric Perspective

Motion Parallax http: //psych. hanover. edu/Krantz/Motion. Parallax. html

Convergence Known angle, inter-ocular separation, Known angle => Depth of fixation point

Accommodation/Blur 1) Knowing your current focal length 2) Blur gradient

Stereo Disparity

Texture Gradient Size, Shape (compression), Density Knill, 1998

Perspective

Shadows/Interreflections

Shadows

Gravity Acceleration profile => Size + Depth Can 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 2) performance in VR 2) 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