Date post: | 14-Dec-2015 |
Category: |
Documents |
Upload: | flora-arleen-sharp |
View: | 217 times |
Download: | 1 times |
Virtual Reality at Boston Virtual Reality at Boston UniversityUniversity
Glenn Bresnahan
Boston University
Scientific Computing and Visualization
(http://scv.bu.edu/DAFFIE/BVRG-Talk-Mar02)
Scientific Computing and Visualizatrion 2
AgendaAgenda
Introduction to Access GridOverview of DAFFIE systemBridging between VR and AGTiled display wallsDemonstrations
3
Access Grid OverviewAccess Grid Overview
Suite of commodity hardware and software– Open source, Open protocol
Multicast Tiled projection wall Approximately 90 installations world-wide
(7 countries)
FOR MORE INFO...
http://www-fp.mcs.anl.gov/fl/accessgrid/
http://scv.bu.edu/accessgrid
Scientific Computing and Visualizatrion 4
Distributed VRDistributed VR
Multi-person, multi-site shared virtual space– Navigation– Avatar representation– Telephony
Scientific Computing and Visualizatrion 5
DAFFIE OverviewDAFFIE Overview
Distributed Applications Framework For Immersive Environments
Component layers–Messaging system– VR protocol– Client applications (agents)
FOR MORE INFO...
http://scv.bu.edu/DAFFIE
Scientific Computing and Visualizatrion 6
DAFFIE Application ClientsDAFFIE Application Clients
ViewerSound server– Telephony generator– Sound player
Behavior agentsAudio/video generators/processorsObject generators/manipulators
Scientific Computing and Visualizatrion 7
DAFFIE EnvironmentDAFFIE Environment
viewerbehavior
agent
soundplayer
viewer
telephony
telephonysoundplayer
behavioragent
behavioragent event event
serverserver
Scientific Computing and Visualizatrion 8
DAFFIE ViewerDAFFIE Viewer
SGI Performer based Mono or stereo display Workstation, CAVE/Immersadesk,
HMD Six-degree of freedom head-tracking Six-degree of freedom navigation Texture-mapped streaming video
Scientific Computing and Visualizatrion 9
DAFFIE ViewerDAFFIE Viewer
Simple "script-based" world description– Geometric models– Animation– Sounds
Many 3D model formats Interaction by picking and/or proximity Local control of time-sensitive animation
and sound Global update of avatar motion and object
state
Scientific Computing and Visualizatrion 10
DAFFIE Sound ServerDAFFIE Sound Server
Telephony generator– Digitize microphone input – Broadcasts "packetized" audio stream – Echo suppression
Scientific Computing and Visualizatrion 11
DAFFIE Sound ServerDAFFIE Sound Server
Sound player input– Multiple sound sources
• Real-time audio streams (e.g. telephony)• Prerecorded object sound files
– Audio attachment objects (3D location)– Avatar position in virtual space– Listener position in physical space
Sound player output– Multi-channel localized audio signals
Scientific Computing and Visualizatrion 12
DAFFIE AgentsDAFFIE Agents
Control object behaviorProximity triggersPortalsDevice interfaces– Kinematic sculptures
Video sourcing (camera)Audio and video processing
Scientific Computing and Visualizatrion 13
DAFFIE ProtocolDAFFIE Protocol
Objective– State consistency– Persistence– Equipotent clients– Network visible state
Message (event) based– Message classes– Delivery service classes
• Globally sequenced, reliable delivery
– Message class subscription
Scientific Computing and Visualizatrion 14
DAFFIE ProtocolDAFFIE Protocol
Compound objects– Geometry– Transformation– Audio hook– Video texture map
Component ownership/object locking– Request ownership– Broadcast changes– Release ownership
Ownership transfer
Scientific Computing and Visualizatrion 15
DAFFIE Messaging SystemDAFFIE Messaging System
Message router (“event server”)– Multiple delivery service classes
• Globally sequenced, reliable delivery
Client application library (API)– Point-to-point and broadcast– Polled or callback (active messages)– Subscription based receive– Multithreaded, non-blocking– Services
• Registration, timing, synchronization, query
Scientific Computing and Visualizatrion 16
DAFFIE Messaging SystemDAFFIE Messaging System
Proxy routers– Fan-in/fan-out
Tunneling– Direct routing for P2P
Scientific Computing and Visualizatrion 17
DAFFIE Message routingDAFFIE Message routing
client
event event serverserver
client
clientproxyproxy
clientproxyproxy
client
client
client
client
client
Scientific Computing and Visualizatrion 18
VR/AG BridgingVR/AG Bridging
Interconnect VR and AG spaces– VR image display over AG– Bridge audio in both directions– Provide interactivity for AG participants• AG navigation• AG interaction tools
– Couple external a/v to both AG and VR
Scientific Computing and Visualizatrion 19
VR/AG BridgingVR/AG Bridging
Boston
Cyberarts
Festival
SC Global
FOR MORE INFO...
http://scv.bu.edu/hipart/GoGrid/
Scientific Computing and Visualizatrion 20
VR/AG BridgingVR/AG Bridging
viewrenderer
audiorenderer
AG node
navigationvideobridge
DAFFIEDAFFIEMulticastMulticast
viewerAGaudio
AG node
Scientific Computing and Visualizatrion 21
Tiled Display WallTiled Display Wall
Benefits– Low cost– Scalable– Multi-use– Passive stereo
Construction– Linux cluster display driver– Inexpensive LCD projectors– Cheap polarizing filters
Scientific Computing and Visualizatrion 22
Tiled Display WallTiled Display Wall
One or two Linux boxes per projector (plus control node)
Two projectors per tileLinear polarizing filtersPolarization-preserving projection
screenCustom fabricated projector mounts– 6 DoF adjusters
Scientific Computing and Visualizatrion 23
Tiled Display WallTiled Display Wall
Prototype configuration– 2x2 stereo array (8 projectors)– 4 Linux display nodes + one control node– Fast Ethernet interconnect
Final configuration– 4x3 stereo array (2 x 9.4 Mpixel)– 24 Linux display nodes + one control node– 52 Linux compute nodes– Myrinet interconnect
Scientific Computing and Visualizatrion 24
Tiled Display WallTiled Display Wall
Software– WireGL/Chromium– VTK– Performer + local synchronization– Movie player (several)– Alignment
• Custom projector mounts• Computerized motor control• Imaging transformation warps• Autocalibration
Scientific Computing and Visualizatrion 25
Tiled Display WallTiled Display Wall
Issues– Software– Alignment
• Custom projector mounts• Computerized motor control• Imaging transformation warps• Autocalibration
– Edge blending• Opto-mechanical• Software