BPC: Art and Computation – Fall 2006BPC: Art and Computation – Fall 2006
Introduction to virtual environmentsIntroduction to virtual environments
Glenn Bresnahan
BPC: Art and Computation – Fall 2006 2
OutlineOutline
High level overview of VR hardware and software (details will be covered throughout the year)– Demonstration of a VR world– 3D Display Wall – how we see in 3D– Animation– Rendering– DAFFIE VR software environment
BPC: Art and Computation – Fall 2006 3
Intro to demo – physical environmentIntro to demo – physical environment
3D Display Wall– Stereoscopic– 3D glasses
Navigation– Game controller– Left joystick:
• Moves U/D• Moves R/L
– Right joystick:• Moves F/B• Turns P(L)/S(R)
– Start button: reset
BPC: Art and Computation – Fall 2006 4
Intro to demo - virtual environmentIntro to demo - virtual environment
Multi-person, multi-site shared virtual space– Navigation– Avatar representation– Telephony
BPC: Art and Computation – Fall 2006 5
3D Display – stereopsis3D Display – stereopsis
Stereoscopic display– Stereopsis – left and right eye view
BPC: Art and Computation – Fall 2006 7
3D display - polarization3D display - polarization
Light is a wave
BPC: Art and Computation – Fall 2006 8
3D display - polarization3D display - polarization
Polarization aligns light in a plane
BPC: Art and Computation – Fall 2006 9
3D display - polarization3D display - polarization
Polarizing filters used to align light Filters rotated 90 degrees block light
Two projectors, one per eye view– Polarizing filters rotated 90 degrees– Matching glasses
BPC: Art and Computation – Fall 2006 10
3D stereoscopic displays – other 3D stereoscopic displays – other techniquestechniquesColored (red-blue) glasses
– Anaglyph
Circular polarizerShuttered glassesDual (head-mounted) display
BPC: Art and Computation – Fall 2006 11
AnimationAnimation
What is animation?
Animate: to give life to; to bring to life
BPC: Art and Computation – Fall 2006 12
AnimationAnimation
What is animation?Traditionally applied to
cartoonsCreation of apparent
motion from still images
BPC: Art and Computation – Fall 2006 13
Animation – pictures in motionAnimation – pictures in motion
BPC: Art and Computation – Fall 2006 15
Animation - principlesAnimation - principles
Creating moving image from a sequence of still images– Each image is displayed for a fraction of
a secondBasis for film,
video, computer graphics, etc.
BPC: Art and Computation – Fall 2006 16
Animation – traditionalAnimation – traditional
Each image (cell) was hand drawn
BPC: Art and Computation – Fall 2006 17
Animation – film and videoAnimation – film and video
Film – individual images (frames) are photographically reproduced on film strip
Video – individual images (frames) are recorded or transmitted as electrical signals
BPC: Art and Computation – Fall 2006 18
Animation – computer graphicsAnimation – computer graphics
Computer generates individual images (frames) and displays them rapidly on a monitor– Technology is very similar to video– Images may also be recorded to film
(e.g. CG special effects) or video
BPC: Art and Computation – Fall 2006 19
RenderingRendering
Creation of a pictorial representation– Generally applied to a realistic depiction
of a 3D scene or objectTypes of rendering
– Artistic rendering– Photographic rendering– Computer rendering
BPC: Art and Computation – Fall 2006 20
Artistic renderingArtistic rendering
Rendering realistic images (perspective)
BPC: Art and Computation – Fall 2006 22
Photographic renderingPhotographic rendering
Camera and film
BPC: Art and Computation – Fall 2006 24
Computer rendering (3D)Computer rendering (3D)
Computer creates an image from a model
A model is a (mathematical) description of the 3D object
BPC: Art and Computation – Fall 2006 26
Computer rendering (3D)Computer rendering (3D)
Computer takes into account the position of the object, as well as the position of the viewer (simulated or virtual camera).
Computer will shade the objects based on position of lights and the surface's material properties.
BPC: Art and Computation – Fall 2006 28
Computer modelsComputer models
Conceptually like a blueprint
BPC: Art and Computation – Fall 2006 30
Computer modelsComputer models begin ./table/items <default> setxfm 1.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 1.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 1.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 1.000000e+00 putprp cull 1 begin ./table/items/cube polygon setxfm 1.500000e+00 0.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 1.500000e+00 0.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 1.500000e+00 0.000000e+00 2.000000e+00 -1.500000e+00 -1.250000e+00 1.000000e+00 defpnt 1 -1.000000e+00 -1.000000e+00 -1.000000e+00 defpnt 2 -1.000000e+00 1.000000e+00 -1.000000e+00 defpnt 3 1.000000e+00 1.000000e+00 -1.000000e+00 defpnt 4 1.000000e+00 -1.000000e+00 -1.000000e+00 defpnt 5 -1.000000e+00 -1.000000e+00 1.000000e+00 defpnt 6 -1.000000e+00 1.000000e+00 1.000000e+00 defpnt 7 1.000000e+00 1.000000e+00 1.000000e+00 defpnt 8 1.000000e+00 -1.000000e+00 1.000000e+00 defpoly 1 2 3 4 0 defpoly 8 7 6 5 0 defpoly 3 7 8 4 0 defpoly 2 1 5 6 0 defpoly 2 6 7 3 0 defpoly 1 4 8 5 0 putprp color 3ff end ./table/items/cube
BPC: Art and Computation – Fall 2006 31
Computer animationComputer animation
Generate multiple images by changing the viewing (i.e. camera) position
Reposition one or more objects between frames
BPC: Art and Computation – Fall 2006 32
Computer animationComputer animation
Render a sequence of models
BPC: Art and Computation – Fall 2006 34
DAFFIE SoftwareDAFFIE Software
DDistributed AApplications FFramework
FFor IImmersive EEnvironments
Glenn BresnahanErik Brisson
Robert Putnam
BPC: Art and Computation – Fall 2006 35
What is VR/VEWhat is VR/VE
Definitions– Immersive, natural interaction, believable
Characteristics– 3D appearance– Stereoscopic display– Large display, wide field of view– 1st person view– Navigation within 3d space (natural interface)– Response to physical position of viewer– Realistic audio
BPC: Art and Computation – Fall 2006 36
DAFFIE WorldsDAFFIE Worlds
Multiple participants– Represented by an avatar– Interact with each other
• Telephony
– Interact with virtual objectsShared virtual space
– All participants experience the same virtual world
BPC: Art and Computation – Fall 2006 37
DAFFIE WorldsDAFFIE Worlds
Shared space divide into roomsrooms Doorways (portalsportals) between rooms Rooms contains objectsobjects Objects
– 3D appearance (3D modelmodel)– May be animated (sequencessequences of models)– May have an appliquéd (2D) image (texturestextures) – May have associated sounds (digital audioaudio)– May react to avatars (people) or other objects
(behaviors via agentsagents)
BPC: Art and Computation – Fall 2006 38
DAFFIE Worlds – Using imagesDAFFIE Worlds – Using images
Images may be appliquéd to the surface of an object
BPC: Art and Computation – Fall 2006 39
DAFFIE Worlds – Using imagesDAFFIE Worlds – Using images
Objects may be flat or curved
Images may be animated by using a sequence of images
BPC: Art and Computation – Fall 2006 40
DAFFIE Software ComponentsDAFFIE Software Components
3D viewer Sound server
– Telephony– Audio mixer & player
Navigation Behavior agents Audio/video generators/processors Object generators/manipulators DAFFIE components communicate over
the network
BPC: Art and Computation – Fall 2006 41
DAFFIE Software EnvironmentDAFFIE Software Environment
viewerbehavior
agent
soundplayer
viewer
telephony
telephonysoundplayer
behavioragent
behavioragent event event
serverserver
BPC: Art and Computation – Fall 2006 42
DAFFIE ViewerDAFFIE Viewer
Supports multiple display devices from workstations to CAVEs
Directly supports advanced input devices (3D trackers, wands, etc).
Simple script-based world description– Geometric models– Animation– Sounds
Many 3D model formats Local control of time-sensitive animation and sound Broadcasts avatar motion and object state
information to other components
BPC: Art and Computation – Fall 2006 43
DAFFIE Sound ServerDAFFIE Sound Server
Provides telephony between participants Mixes and plays multiple sound sources
– Real-time audio streams (e.g. telephony)– Prerecorded object sound files
Sound is localized in 3D space– Originates at 3D virtual object location– Heard relative to the avatar’s position– Played relative to listener position in physical space
(when tracked) Sound player output
– Multi-channel localized audio signals which can be played into a speaker array
BPC: Art and Computation – Fall 2006 44
DAFFIE NavigationDAFFIE Navigation
Advanced device support built-in to the viewer
Windows-based navigation client– Game controllers– Hand-held pointing devices (Gyro Pointer)– Mouse– Keyboard
Can control one or more avatars
Top Related