BPC: Art and Computation – Fall 2006 Introduction to virtual environments Glenn Bresnahan

BPC: Art and Computation – Fall Outline 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 Intro 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 Intro to demo - virtual environment Multi-person, multi-site shared virtual space –Navigation –Avatar representation –Telephony

BPC: Art and Computation – Fall D Display – stereopsis Stereoscopic display –Stereopsis – left and right eye view

BPC: Art and Computation – Fall Stereoscopic display Viewmaster

BPC: Art and Computation – Fall D display - polarization Light is a wave

BPC: Art and Computation – Fall D display - polarization Polarization aligns light in a plane

BPC: Art and Computation – Fall D 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 D stereoscopic displays – other techniques Colored (red-blue) glasses –Anaglyph Circular polarizer Shuttered glasses Dual (head-mounted) display

BPC: Art and Computation – Fall Animation What is animation? Animate: to give life to; to bring to life

BPC: Art and Computation – Fall Animation What is animation? Traditionally applied to cartoons Creation of apparent motion from still images

BPC: Art and Computation – Fall Animation – pictures in motion

BPC: Art and Computation – Fall Animation – component images

BPC: Art and Computation – Fall Animation - principles Creating moving image from a sequence of still images –Each image is displayed for a fraction of a second Basis for film, video, computer graphics, etc.

BPC: Art and Computation – Fall Animation – traditional Each image (cell) was hand drawn

BPC: Art and Computation – Fall Animation – 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 Animation – 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 Rendering Creation of a pictorial representation –Generally applied to a realistic depiction of a 3D scene or object Types of rendering –Artistic rendering –Photographic rendering –Computer rendering

BPC: Art and Computation – Fall Artistic rendering Rendering realistic images (perspective)

BPC: Art and Computation – Fall Artistic rendering Trompe l’oeilGone bad

BPC: Art and Computation – Fall Photographic rendering Camera and film

BPC: Art and Computation – Fall Photographic rendering Camera obscura

BPC: Art and Computation – Fall 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 Computer rendered image

BPC: Art and Computation – Fall 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 Computer rendering process

BPC: Art and Computation – Fall Computer models Conceptually like a blueprint

BPC: Art and Computation – Fall Computer models

BPC: Art and Computation – Fall Computer models begin./table/items setxfm e e e e e e e e e e e e e e e e+00 putprp cull 1 begin./table/items/cube polygon setxfm e e e e e e e e e e e e e e e e+00 defpnt e e e+00 defpnt e e e+00 defpnt e e e+00 defpnt e e e+00 defpnt e e e+00 defpnt e e e+00 defpnt e e e+00 defpnt e e e+00 defpoly defpoly defpoly defpoly defpoly defpoly putprp color 3ff end./table/items/cube

BPC: Art and Computation – Fall Computer animation Generate multiple images by changing the viewing (i.e. camera) position Reposition one or more objects between frames

BPC: Art and Computation – Fall Computer animation Render a sequence of models

BPC: Art and Computation – Fall Computer animation

BPC: Art and Computation – Fall DAFFIE Software DAF FIE D istributed A pplications F ramework F or I mmersive E nvironments Glenn Bresnahan Erik Brisson Robert Putnam

BPC: Art and Computation – Fall What is VR/VE Definitions –Immersive, natural interaction, believable Characteristics –3D appearance –Stereoscopic display –Large display, wide field of view –1 st person view –Navigation within 3d space (natural interface) –Response to physical position of viewer –Realistic audio

BPC: Art and Computation – Fall DAFFIE Worlds Multiple participants –Represented by an avatar –Interact with each other Telephony –Interact with virtual objects Shared virtual space –All participants experience the same virtual world

BPC: Art and Computation – Fall DAFFIE Worlds rooms Shared space divide into rooms portals Doorways (portals) between rooms objects Rooms contains objects Objects model –3D appearance (3D model) sequences –May be animated (sequences of models) textures –May have an appliquéd (2D) image (textures) audio –May have associated sounds (digital audio) agents –May react to avatars (people) or other objects (behaviors via agents)

BPC: Art and Computation – Fall DAFFIE Worlds – Using images Images may be appliquéd to the surface of an object

BPC: Art and Computation – Fall DAFFIE Worlds – Using images Objects may be flat or curved Images may be animated by using a sequence of images

BPC: Art and Computation – Fall DAFFIE 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 DAFFIE Software Environment viewer behavior agent sound player viewer telephony sound player behavior agent behavior agent event server

BPC: Art and Computation – Fall DAFFIE 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 DAFFIE 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 DAFFIE 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

BPC: Art and Computation – Fall DAFFIE Behavior Agents Control object behavior Proximity triggers Portals Device interfaces –Kinematic sculptures Video sourcing (camera) Audio and video processing