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Convergence vs accommodation

it happens when your brain recieves mismatching ues between the distance of virtual object and the focusing distance required for the eyes to focus on that object

Accommodation

It's the process of changing the shape of eye, contracting or relaxing muscles in the eye. This helps us to judge distance from an object we look at

Stereo vision as depth cue

each eye recives slightly different view of world, which is then combined to percieve 3D depth. Object is projected onto 2 reinae depening on the distance of object. The disparity varies with the object distance

Cave and HMD rendering frame?

60 fps for CAVE, 90 for HMD

Human field of view (horizontal, vertical, stereoscopic)

horizontal - 2*90, vertical - 120, stereoscopic - 100-120

HMD, CAVE field of view od regard

HMD: FOV-much smaller than human eye, FOR - can get to 100% with good tracking system//// CAVE FOV-might get up to the same as human eye, FOR: depends on arragment and distance of projection surface

color fidelity of polarization and infinitec

polarization +, infinitec -

Broad Phase?

can objects possibly intersect? Test bounding volume

Narrow Phase

Test the individual primitive intersections. Use individual triangles etc.

gain of the screen material: polarization vs active stereo

polaritzation: screen material may not be destroyed, brightness uniformity(-), active stereo: screen material may be diffuse, brightness uniformity (+)

pros and cons of passiive stereo with polarization and active stereo with shutter glasses in a projector based VR system

polarization: ghosting may occur, good colors, buffer snap, medicore cost, screen material must maintain polarization./////// Shutter Glasses: no ghosting, good colors, buffer snap, glasses, projector, cost: expensive, screen material: arbitary

name cues that provide depth in VR

stereopsis, ocular motor factors, motion paralax

describe HOMER and pros and cons of homer

Hand-cetnered Object Manipulation Extanding Ray-casting///selecting objects later manipulated by natural hand (+)unlimited selecation range (-)limited manipulation range

Voodoo Dolls

manipulating miniature copy of objects (+) manipulation independant of distance, size or occlusion (-) requires two 6DoF devices

2 handed ray

+more precise than one handed +specify ray length via distance between hands, -2device, -fatigue, -cumbersome

ray

+easy,+accurate, -hard to select small or far away objects, -high angular precision needed

flashlight

+not high precision needed, -hard to point at small and crowded objects

interSelect

+reduces jittering, +easy to select small, crowded, moving objects////////// -only works for lines/points/objects they can approximate

Convergence

depth cue about focusing distance for the eye to focus on the object

Name the difference between and the advantages/disadvantages of active and passive optical tracking.

active: LEDs, require cabling. ///// passive: retro-reflecting markers, no cabling.