16-17. depth 1&2 Flashcards
Many to one representation meaning?
There are many different 3D scenes that can produce the exact same retinal image
- a big balloon far away
- a small balloon really close
- a medium balloon in the middle
Retinal size depends on…? (2 things)
- size of object
- distance to object
Ways to divide depth cues?
(3 levels of tree diagram)
- oculomotor vs retinal image
- monocular vs binocular (disparity)
- mono: static vs dynamic
Oculomotor cues meaning? 2 types? Problem?
- cues based on feedback from muscles controlling shape of lens and position of eyes
- neither are very precise or super helpful
- accommodation
- convergence
2 types of monocular cues (and meaning) ?
- only need one eye to provide depth information
- static (doesn’t need motion)
–> all info is in a picture - dynamic (requires motion)
3 types of static cues?
- position based
- size based
- lighting based
2 position based cues?
- partial occlusion
- relative height
Position of things relative to each other
4 size based cues?
- familiar size
- relative size
- texture gradients
- linear perspective
change in size (relative) gives you depth info
3 lighting based cues?
- atmospheric (aerial) perspective
- shading
- cast shadows
lighting info = depth info
3 dynamic cues?
- motion parallax
- optic flow
- deletion and accretion
Accommodation def? Type? (Problem?)
Oculomotor
- detect change in ciliary muscles to adjust lens to focus on the object
- VERY limited range (<2m)
- Even within that range, may still be very imprecise
Convergence def? Type? (Problem?)
Oculomotor
- detect how converged your eyes become to focus on an object
–> far away = not converged
–> super close = very converged - VERY limited range (<2m)
–> beyond that, the angle between your eyes changes very little
Partial occlusion def? Type of cue?
Monocular - static - position based
If an object partially covers another, you perceive the former (cover-er) as closer than the latter (covered)
*very reliable
Relative height** def? Type of cue?
Mono - static - position
An object that is closer to the horizon (or eye level) appears farther away
Think of the beach/inlet scene
Size-distance relation meaning?
- the farther away an object is, the smaller its retinal image
- RETINAL size decreases proportional to the increase in distance
Familiar size def? Type of cue?
mono - static - size
- use the retinal image size of a familiar object to judge our distance to it
- we know the retinal image size of familiar objects at familiar locations
Relative size def? Type of cue?
mono - static - size
- if several objects (ex. people) are all about the same physical size, we use RELATIVE size of retinal images to judge distances
- familiar objects are the same size, but some appear much bigger –> helps judge distance
Texture gradient def? Type of cue?
mono - static - size
- if surface variations or repeated elements of a surface are fairly regular in size and spacing, the retinal image size of these equal-size features decreases as their distance increases
Accelerated texture gradient meaning?
- Adjusting the spacing between repeated elements in a design
- creates illusion to make a building look longer/taller etc