Lecture 2 Summary
The Immersed User & Natural User Interfaces
1. What Determines Visual Reality?
For a display to be perceived as "real," it must satisfy several perceptual criteria:
Image fills the entire field of view (no external frame)
Resolution and intensity limited only by the visual system's sensitivity
Dynamic depth information (movement parallax) is coupled to observer motion in
real-time
Static depth cues (linear perspective, interposition, texture gradients, binocular
disparity) are consistent and spatially coherent
2. History: From Cave Paintings to CAVEs
A long lineage of technologies has attempted to create immersive experiences:
Era Technology Key Feature
Prehistory Cave wall paintings Earliest spatial narrative
1792 Panoramic paintings (Barker, 360° immersive scenes
Mesdag)
Mid-17th Magic Lanterns / Phantasmagoria Projected moving images
C
1839 Daguerreotype (Daguerre) Photography
1870s Chronophotography (Muybridge) Sequential motion capture
1894 Edison Kinetoscope Individual motion viewing
1895 Lumières' cinema Projected moving images for audiences
1939 RCA Teleceiver Television
1950s Stereoscopic 3-D film Binocular depth in cinema
1952 Cinerama 146° wide-screen + 7-channel sound
1955/62 Sensorama (Heilig) Multi-sensory (3D, smell, wind,
vibration)
1965 Sutherland "Ultimate Display" Interactive graphics + force feedback
, Era Technology Key Feature
1967 Sutherland HMD First head-mounted display
1980 Minsky – Teleoperation & "Sense of being there"
Telepresence
1991 Krueger / Lanier – Virtual Reality Goggles 'n' gloves paradigm
1992 Four-sided CAVE (Univ. of Illinois) Room-scale VR
1998 Six-sided CAVE (KTH) / CyberSphere Full immersion systems
2012+ Oculus Rift / Google Cardboard Consumer VR
Morton Heilig: "Virtual reality is dreams — sophisticated instruments give you the
power to do it more easily."
3. Defining Virtual Reality
Technology-based definition (Greenbaum)
VR = alternate world with computer-generated images responding to human movements,
visited via data suits, stereoscopic goggles, and fiber-optic gloves.
Limitation: excludes CAVEs, Oculus Rift, etc.
Experience-based definition (Ellis)
VEs are interactive, head-referenced computer displays that give users the illusion of
displacement to another location.
Presence-based definition (Steuer) ⭐
A VR is a real or simulated environment in which a perceiver experiences telepresence.
Steuer's Two Dimensions of VR
Vividness = richness of representation
Breadth: sensory channels (sight, sound, touch, smell)
Depth: quality/fidelity per channel
Interactivity = extent user can modify the environment
Speed: update rate, latency
Mapping: text → speech → gesture → gaze → complex behaviour
The Immersed User & Natural User Interfaces
1. What Determines Visual Reality?
For a display to be perceived as "real," it must satisfy several perceptual criteria:
Image fills the entire field of view (no external frame)
Resolution and intensity limited only by the visual system's sensitivity
Dynamic depth information (movement parallax) is coupled to observer motion in
real-time
Static depth cues (linear perspective, interposition, texture gradients, binocular
disparity) are consistent and spatially coherent
2. History: From Cave Paintings to CAVEs
A long lineage of technologies has attempted to create immersive experiences:
Era Technology Key Feature
Prehistory Cave wall paintings Earliest spatial narrative
1792 Panoramic paintings (Barker, 360° immersive scenes
Mesdag)
Mid-17th Magic Lanterns / Phantasmagoria Projected moving images
C
1839 Daguerreotype (Daguerre) Photography
1870s Chronophotography (Muybridge) Sequential motion capture
1894 Edison Kinetoscope Individual motion viewing
1895 Lumières' cinema Projected moving images for audiences
1939 RCA Teleceiver Television
1950s Stereoscopic 3-D film Binocular depth in cinema
1952 Cinerama 146° wide-screen + 7-channel sound
1955/62 Sensorama (Heilig) Multi-sensory (3D, smell, wind,
vibration)
1965 Sutherland "Ultimate Display" Interactive graphics + force feedback
, Era Technology Key Feature
1967 Sutherland HMD First head-mounted display
1980 Minsky – Teleoperation & "Sense of being there"
Telepresence
1991 Krueger / Lanier – Virtual Reality Goggles 'n' gloves paradigm
1992 Four-sided CAVE (Univ. of Illinois) Room-scale VR
1998 Six-sided CAVE (KTH) / CyberSphere Full immersion systems
2012+ Oculus Rift / Google Cardboard Consumer VR
Morton Heilig: "Virtual reality is dreams — sophisticated instruments give you the
power to do it more easily."
3. Defining Virtual Reality
Technology-based definition (Greenbaum)
VR = alternate world with computer-generated images responding to human movements,
visited via data suits, stereoscopic goggles, and fiber-optic gloves.
Limitation: excludes CAVEs, Oculus Rift, etc.
Experience-based definition (Ellis)
VEs are interactive, head-referenced computer displays that give users the illusion of
displacement to another location.
Presence-based definition (Steuer) ⭐
A VR is a real or simulated environment in which a perceiver experiences telepresence.
Steuer's Two Dimensions of VR
Vividness = richness of representation
Breadth: sensory channels (sight, sound, touch, smell)
Depth: quality/fidelity per channel
Interactivity = extent user can modify the environment
Speed: update rate, latency
Mapping: text → speech → gesture → gaze → complex behaviour
