DCS861D: The User Interface from Front to Back
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Collaboration
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Computer-supported Cooperative Work, Telepresence, and Collaborative Virtual Environments
Cyberspace
Definition (Michael Benedikt, editor, Cyberspace:
First Steps, 1994)
"Cyberspace: A word from the pen of
William Gibson, science fiction writer, circa 1984 . . . A new universe, a
parallel universe created and sustained by the world's computers and
communication lines . . . The tablet become a page become a screen become a
world, a virtual world . . . A common mental geography, built, in turn, by
consensus and revolution, canon and experiment . . . Its corridors form
wherever electricity runs with intelligence . . . The realm of pure
information . . . "
Computer-Supported
Cooperative Work (CSCW)
- Computer-assisted coordinated activity carried out by groups of
collaborating individuals
e.g.
- communication
- problem solving
- co-authoring a document
- Groupware - information technology used to help people work
together more effectively.
- Groupware makes user aware that he is part of a
group.
- Groupware defined by Peter and Trudy
Johnson-Lenz (1982) their ideas included:
- messaging
- conferencing
- filtered exchanges
- relational structures
- voting
- decision support tools
- Computer Supported Cooperative Work (1984) coined by Gireif and Cashman
- Today serves as a forum -
collaborative/cooperative a metaphor, it could support competition.
Paradigm Shift for Computing
- Transformation from human-machine to human-human interaction
Results from several convergent phenomena:
- Pervasive networking
- Growth of workgroup computing
- Growth of technology supporting executive and
managerial group decision making
- Merging of telecommunications and computing
supporting applications such as video conferencing
- Advancement in work-at-a-distance
- New technologies - ISDN, DSL, cable modem
- Widespread groupware:
- Email
- Computer conferencing (aka
structured email)
- Teleconferencing (use of audio/video)
- Joint problem solving:
- Collaborative writing or drawing
- Group decision support systems (with
electronic meeting rooms)
CSW Taxonomy
- DeSanctis and Gallup (1987) - 2x2 matrix differentiates groupware
technologies into two groups - bridge time and bridge space
- Today systems are moving toward anytime/anyplace
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One
Meeting Site
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Multiple
Meeting Sites
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Synchronous
Communications
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Face-to-Face
Interactions
- Public Computer Displays
- Electronic Meeting Rooms
- Group Decision Support
Systems
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Remote
Interactions
- Shared View Desktop
conference Systems
- Desktop Conferencing with
Collaborative Editors
- Video Conferencing
- Media Spaces
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Asynchronous
Communications
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Ongoing
Tasks
- Team Rooms
- Group Displays
- Project Management
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Communicationand Coordination
- Vanilla email
- Async conferencing bulletin boards
- Stuctured messaging systems
- Workflow management
- Version Control
- Meeting Schedulers
- Cooperative hypertext,
organizational memory
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Asynchronous Groupware
- Supports communication and problem solving among groups of
individuals who contribute at different times
- Email and computer conferencing systems
- Structures messaging systems
- Cooperative hypertext or hypermedia systems
- Email and Computer Conferencing
- Most successful: asynchronous, fast, can be
sent to multiple receivers, has built-in external memory
- Can contain text, image, video, sound
- Organized email:
- Computer conferencing system:
Messages organized by topic, emphasizing
dialogue
e.g.
Comic Chat (Microsoft)
(D. Kurlander, David
H. Salesin, T. Skelly. "Comic Chat." Proceedings of SIGGRAPH 96,
in Computer Graphics Proceedings, Annual Conference Series, 225-236, August
1996.)
- Electronic bulletin boards:
Messages organized by time, emphasizing
broadcast of information
- Case study by Sproull
and Kiesler (1991)
- Electronic communications increase informational
and emotional connections of employees
Especially
those geographically or hierarchically peripheral to center of activity
- Two groups working on project
- One group used electronic communication other
not
- e - supported group achieved greater breadth
of access and greater opportunity to lead or participate
- Result: higher degree of contact, felt more
involved in group work, reported less communication isolation
Structured Messages, Agents
and Workflow
- Structured messaging systems - better methods of organizing, classifying, filtering, and
managing messages
- Agent - create
intelligent messaging system delegating tasks to computer process
- Workflow - focus on
messages that define processes - sets of rules which create conversations
Cooperative Hypertext and
Organizational Memory
- Applications which focus on messages or documents and their
interrelationships - cooperative hypertext systems
- Support:
- collaborative knowledge building
- Asynchronous collaborative writing
- Creating organizational memory
- e.g. Schatz (1991-1992)
- Community systems project - build electronic
scientific community by collecting all community's scientific Knowledge
and make available
- The Telesophy System
- 500 researchers studying the nematode worm
- Extend support beyond document to include
process. (Conklin 1992)
- Software integrates three technologies:
- Hypertext, groupware, and a rhetorical method
(improves dialogue and conversational record and Organizational memory
- Most successful organizational memory - Lotus
Notes
- Integrated communications and database network
application
- Designed to gather, organize, distribute
information among workgroups
- Platform for developing workgroup applications
- Used for message routing, report distribution,
idea discussion, and for tracking and managing projects
- Biggest application - Price-Waterhouse (tens
of thousands of notes licenses) why?
- No on knew who had knowledge to solve a
particular problem
- Constantly reinventing wheel worldwide
- Need for better communication
- Results:
- Retention of knowledge
- Support for global collaboration and global
discussion
- Enhanced communication
Synchronous Groupware
- Software that assists a group of individuals in working together simultaneiously to carry out a task
- Four classes:
- Desktop conference systems (e.g. outlining,
writing, sketching, spreadsheet)
- System infrastructure for desktop conferencing
- Electronic meeting and decision rooms
- Media spaces that include computer controlled
AV networks and virtual meeting environments
- Desktop Conferencing Systems
- NLS shared-screen conferencing systems 1968
-augment face-to-face communication
- Xerox Parc Colab Project 1987
- Tools for collaborative brainstorming,
argument development, free style sketching
- Workstation-based with large touch screen in
front of room
- WYSIWIS (what you see is what I see)
- System Infrastructure for Desktop Publishing
- Two approaches to developing groupware:
1.
Collaboration
transparency - single user software
made available to group
2.
Collaboration aware - rewritten software for group use
- #1 is simplest approach - some software run on
multiple workstations under control of screen sharing software
- Example Systems:
- Electronic Meeting and Decision Rooms
- Decision support systems - work in electronic
meeting room
Supports
parallel or sequential activity
- Support:
- Idea generation
- Idea organization
- Voting
- Media Spaces
- An electronic setting in which:
- groups of people can work together, even when they are not resident in
the same place or present at the same time.
- people can create real time visual and acoustic environments that can
span physically separate areas.
- people can control the recording, accessing of
recorded images and sounds from those environments"
- Research Agenda the move from PERSONAL to
INTERPERSONAL computing
- Use new media (audio and video transmission)
to create a space for human-human interaction
- Always on
- You don’t “connect
to” a space, you are “in it”
- Provide opportunities for engagement
- Support social interactions
- Informal and serendipitous interactions
- Support awareness
- Existence and presence of colleagues
- Work status (e.g., for communication
coordination)
- Beginnings:
- Picture (Video) Phones
- “When two-way television is added to
telephones, […] direct interaction will finally be available to those
who are widely separated” - Erving Goffman, Behavior in Public Places, 1963
- Bell Telephone - 1964 NY World’s
Fair
- “Mod 1” (AT&T Picture phone)
- Connection from New York to Disney World in Florida.
- Picture quality bad -
screen too small , frame rate low (~ 0.5 fps).
- Hole-in-Space
Experiment (1980)
- Artists Kit Galloway and Sherri Rabonwitz set up a two way video connection between
outdoor public pedestrian spaces in Century City, CA and Lincoln
Center, NYC.
- Images of pedestrians were projected at
approximately full-scale, and transcontinental casual pedestrian
encounters could take place.
- Mid 1980s XeroxPARC
- Media Space
- (R.Stults, Media
Space. Xerox Corporation, Palo Alto. 1986)
- Geographically split between Palo Alto, CA and Portland, OR.
- Maintain single group & explore
technologies to support collaborative work
- The media space provided a sense of PERIPHERAL
awareness
- being aware of the coming and goings
required no response,
- provided an overview of who was around and
what was happening (and afforded the possibility of joining in)
- Used for:
- chance encounters
- locating colleagues
- video phone conversations
- group discussions
- replaying video records
- records of meetings/talks were available
- use of video memos
- Project reconfigured "media space"
to enable the distributed group's
presentations
social activities
- Success of media space due to its ability to
support a wide range of work related activities
- Findings
- Frequent and regular use of the media space
for awareness, informal interactions, and for sharing culture indicated
that is supported MORE than task specific interaction.
- The media space supported group maintenance
across distance
- Issues
- Scalability
- Did not replace face to face communication,
but acted as a sustainer of working relationships
- Integration of shared technologies was not
sufficient to support focused task activity
- Other Early Systems
- Hiroshi Ishii - Teamwork System
- Display of shared digital workspaces with
displays of drawing surfaces and desktop materials
- Implements seamlessness between individual
and workgroup by overlaying translucent workgroup by overlaying
translucent workspace images-live video analog images of computer
screens and desktop surfaces
- Computer screen overlay is a shared screen
combining windows from individual collaborators
- Creates shared interpersonal space using
small windows displaying live video of one's collaborator
- Extended with ClearBoard
- VideoWindow: Bellcore
- Large screen display with live audio between
two public areas on different floors of a research lab.
- Oft-repeated “video wall” concept
Another attempt at joining break rooms see for
example: Gavin Jancke, Gina Danielle Venolia, Jonathan Grudin, J. J.
Cadiz, Anoop Gupta," Linking public
spaces”, Proceedings of CHI '01, March 2001, pp. 530-537
- Try to join to spaces (break rooms) by
placing camera and (very wide) video display against a wall
- Other space looks like its “past the wall”
- High quality media setup (special camera
& display, etc.)
- Some success
- Remote participants interacted (much like
local)
- But not “being there”
- (Fish, RS, Kraut, RE & Chalfonte, BL (1990) The VideoWindows
system, Proceedings of CSCW90, LA, CA)
- Cruiser: Bellcore
- Designed explicitly around social phenomena
- (Partially) modeled after walking down the
hall - “Cruising”
- More like random telephone calls than walking
down hall
- Connection of offices for informal
interactions.
- Based on a model of walking down a hallway
and popping ones head into a doorway.
- Incorporated reciprocity (i.e. one could see
who was popping in)
- User access control.
- (Fish, RS, Kraut, RE, Root, RW & Rice RE.
(1993) Video as an technology for Informal Communication, Comms of the ACM, Vol 36,
No 1, 8-61)
- RAVE: Xerox EuroPARC
- Support of both offices and common areas.
Important addition was the extensive use of audio for
a variety of informational cues, (eg signalling that it is time for a meeting).
- The interface provided the following actions:
- glance
- video phone calls
- office sharing
- background viewing
- User controlled access both to view and of
responses to access requests. Audio feedback was also provided on the
occurrence of a glance.
- (Gaver, WW, Moran
TP et al (1992) Realising a Video
Environment: EuroPARC¹s RAVE System, Proceedings of CHI92)
- CAVECAT (University of Toronto)
- Investigation of how the combination of
groupware and audio/video technologies could becombined
to enhance collaboration at a distance.
- System supported 10 offices in a single
building.
- Same low level infrastructure RAVE
- Same computer controlled analog switch
- Used 4-up display
- Small group instead of simple point-to-point
- (Marilyn M. Mantei,
Ronald M. Baecker, Abigail J. Sellen, William A. S. Buxton, Thomas Milligan,
Barry Wellman, “Experiences in the use of a media space”, Proceedings
of CHI '91, March 1991, pp. 203-208. )
- Some identified needs from early systems
- Informal communications support
- Social interactions are inherently informal
- Need spontaneity and serendipity
- A lot of work gets done “bumping into” people
in the hall
- Requires very lightweight interactions
- Low intentionality
- Need to support unstructured, complex, &
equivocal communications
- Awareness
- General (background / peripheral) information
about collaborators makes interaction smoother
- Lots of very informal information
- Existence, presence/absence
- Activities, busyness, mood, habits, …
- Not (necessarily) task-oriented
communications but still makes tasks smoother
- e.g., coordination of communications (when to
interrupt)
- Each piece of information has low value, but
valuable in the aggregate
- Can’t incur much cost to get each piece
- Leads to need for ambient displays
- Smooth transition from informal to direct
communications
- Direct communications still critical for
“getting work done” (task oriented actions)
- Shared artifacts / documents very important
for direct communications
- Media-related issues
- View
- Field of view & resolution
- Perceptual and privacy implications
- Anisotropic views
- Loss of gaze awareness, social distance
distortions
- Missing view control
- Missing movement parallax & stereopsis
- Audio
- General quality and noise
- Loss of localization
- Control & Privacy
- Most early systems (partial exception Bellcore) were used mostly by creators and their
friends
- Highly motivated and self-selected
- Still privacy issues raised by all
investigators
- Camera is like working in front of a 1-way
mirror
- Can’t tell who’s
looking (loss of reciprocity)
- Like real world situations
- e.g., the man lurking behind the bush
- Loss of reciprocity breaks social convention
=> unease
- Other social aspects
- Missing cues for public / private nature of
space
- Missing cues for approach & negotiation
- Social interaction prerequisites
- Concentration of suitable partners
- Co-Presence
- Opportunity to engage
- Low personal cost
- Visual channel
- Cues for engagement are primarily visual
- Distance related issues
- Time zone issues
- Cultural issues
Virtual
Communities
"Virtual communities are social
aggregations that emerge from the Net when enough people carry on those public
discussions long enough, with sufficient human feeling, to form webs of personal
relationships in cyberspace"
- Characteristics(Quentin Jones)
-
- Minimum Level of Interactivity
- Variety Of Communicators
- Common-Public-Space Where a Significant Portion
of a Community's Interactive Group-CMC Occurs
- A minimum level of sustained membership
- Example Communities:
- BBs
- The WELL
- Considered to be one of the oldest virtual
communities on the Web.
- Currently it consists of 10,000 participants.
- Name stands for "whole earth 'lectronic link, which was an outgrowth of the whole
earth catalog started
in 1985
- Physicians'
Online® Network (POL)
- Third Age
- MUDs
(Multiple User Dimension, Multiple User Dungeon, or Multiple User
Dialogue)
- A program which users can log into and
explore.
- Each user takes control of a computerized
persona/avatar/incarnation/ character.
- Users can walk around, chat with other
characters, explore dangerous monster-infested areas, solve puzzles, and
even create your very own rooms, descriptions and items.
- MOOs -
- Internet-accessible, text-mediated virtual
environments suited for distance learning.
- Every participant can construct spaces and
objects and write code that augments or increases the functionality
with these virtual spaces.
- MOOs are constructed social spaces in a dynamic
process of continual evolution.
- MOOs are constellations of spaces, or
"rooms", within which multiple individuals can congregate
and interact.
- Sample Site:
MBone
- MBone is the Internet's multicast backbone.
- Multicast distributes data from one sender to
multiple receivers with minimal packet duplication.
- Types of _casting:
- Broadcasting - traffic sent from a source is distributed
to all segments of the network, even portions where there are no
receivers for the message.
- Used primarily on LANs where servers may
advertise their availability to small groups of machines and clients
may poll for certain services
- Unicasting - sends data only to the portions of the
network where there are users interested in receiving it BUT a new
copy of the data must be sent for each individual receiver making the
technology inefficient.
- Primary technology used on the Internet for
such applications as e-mail, FTP, and the WWW
- Used for multimedia services such as Real Audio/Real Video
- Multicasting - one copy of the data is sent only to the
portions of the network where there are users interested in receiving
it - made possible by routing processes that keep track of the data
streams in use and adjust the data routing rules accordingly.
- Not widely implemented on the Internet
- MBone is constructed by connecting together portions
of the Internet that have implemented multicasting
- MBone formed by building "tunnels" that
encapsulate multicast data into unicast data
packets while
travelling between multicast-enabled portions of the network.
The
collection of multicast tunnels forms a virtual multicast network (the MBone) that is implemented over the traditional Internet
network.
- MBone transmits across the Internet real-time
video and audio streams for conferences and
meetings.
- (e.g. congressional sessions and NASA
shuttle launches)
- MVC - MBone VideoConferencing Tools
- "VIC"
(VIdeo Conferencing), by the Network
Research Group at the Lawrence Berkeley National
Laboratory (LBL).
- VIC displays a thumbnail-sized picture of each
transmitting source along with identification and bandwidth
information.
- VIC users can select one or more of these
sources for a larger display.
- Users can control their video
transmissions by selecting options from a "menu" panel
(not shown).
- A video frame rate of 4-6 frames per
second for most video material.
- "VAT"
(Visual Audio Tool) also developed at
LBL.
- A list of users participating in the
session is displayed on the left side of the tool while microphone
and speaker controls are displayed on the right.
- VAT users can obtain more information
about other users by selecting a name in the list.
Users control various audio options from a
"menu" panel.
University College
London Site for MBone Tools
Telepresence
Definition
Telepresence is the use of virtual reality to enter a shared,
cyberspace, graphic environment for the purposes of human communication and
interaction, or to become electronically present in a distant real-world
environment for the purposes of remote-controlled action and / or observation.
- Key determinant of telepresence in the
mediated environment is the user's sensory immersion into the mediated
information
- Influenced by the degree to which user's sensory bandwidth is
engaged by the interface
- A user's sense of presence is related to the amount of information
coming from the physical environment versus the virtual environment
- e.g
- visual channel - sensory saturation is often manipulated by increasing
the percentage of the field-of-view occupied by the visual display
Early Work:
Myron Krueger - Videoplace - non-invasive (video camera, image
processing)
- "Videoplace" perceives one or more participants and responds to their
movements in realtime using video cameras.
- "Videoplace"
identifies each participant's head, arms, legs, hands and fingers
and determines their rate of movement.
- Each participant's image may be moved, scaled or rotated anywhere
on the screen.
- "Videoplace" has two modes:
- It interacts directly with an individual.
- It mediates a dialog between two participants:
- one who understands and controls the system
- a
second naive participant.
- The controller can interact with the other
person by using the image of his or her hands.
Contemporary Applications:
Telesurgery
World's First Full
Telesurgery a Success
- Professor Jacques Marescaux and his
40-person team from the Institute for Research
into Cancer of the Digestive System (IRCAD)
- Working from New York on September 7, Marescaux removed the
gallbladder from a 68-year-old woman in Stroudsburg, France (4300 miles)
- New York: Video screen and controllers connected
with high-speed fibre-optic line
- Stasbourg: Zeus
laparoscopic surgical robot
- Time delay between his movements in NY, action in
France and the visualization of that movement on the
NY screen was 155 milliseconds
- Operation cost $1 million
Collaborative
Virtual Environments (CVEs)
CVE is a distributed
multi-user virtual reality system:
- Networking based on IP multicasting;
- Support for the new extended spatial model of interaction,
including third parties, regions and abstractions;
- Multiple users communicating via 3D graphics, real-time packet
audio and text;
- Extensible object oriented (class-based) developers API
CVEs for CSCW:
- The ability to present a large amount of information
- Natural information lensing
- Support for many sensory modalities
- Natural multi-user interaction
- Natural awareness of co-workers' activities
Teleconferencing
in Collaborative Virtual Environments:
- Ordinary teleconferences suffer from a lack of spatial cues
- Virtual environments add spatialised
sound support for directing attention and pinpointing sound sources
outside the field of view
- Gaze direction as indicator of attention
- Spatial presence and activity of participants
Structure
of CVEs:
- Shared artifacts
- Applications can be represented in the virtual
environment and used concurrently or alternatingly
by the participants.
- Embodiments
- User representations in the virtual environment
indicate
- Presence
- Identity
- Position
- Attention
- Activity
- Hardware capabilities
- Personality
- e.g. Conferencing participants gathered around
a table:
- Embodiments with ears indicate users with
audio capability
- Those with Ts embossed in their faces are
limited to a text-only
- The "owner" of the supine embodiment
has probably left his workstation in the real world and indicated this
by lying down.
- Spatial Model (e.g. MASSIVE CVE)
- Gives support for direction of attention,
public addressing, and private
conversations using as close to normal body language as possible.
- Set of subspaces defined around the user's
embodiment
- Focus
defines the extent of the user's attention
- Nimbus defines the extent of the user's presence in
the world
- Focus and nimbus are enveloped by the aura
- When one user's focus intersects another
user's nimbus the first becomes aware of the second.
- Subjective Representations
- Different participants do not necessarily have
to see their environment in the same way
Supporting
Tele-Immersive Environments
- Communication
- Use of video and audio conferencing
- Use of avatars to provide a representation of
the participant in the environment and convey gestural
cues (pointing at objects, waving of the hand, nodding and shaking of the
head) that augment audio communication
- Synchronous and asynchronous collaboration
- Persistent environments assume ability to work
in an environment
- at the same time with other participants
(synchronously),
- in
addition to being able to work in the same environment at different
times (asynchronously).
- Any changes made to the environment must
persist for when the other participants return
- Recordability
- The ability to record virtual experiences for
later playback or continuation
- Allows participants to place annotations in the
environment so that other participants may view them at
a later time
- Collaborative interaction and manipulation
- Tools to enable participants to interact and
manipulate shared objects and datasets being visualized in
the environment
- Tools must guarantee that proper consistency is
maintained across each participant's view of the environment, especially
when multiple participants attempt to modify the same shared object.
- Connectivity with external resources
- Tools to enable them to easily interface their
existing non-VR tools/applications with the virtual environment
- Application developer issues
- Modules for audio and video compression
- Modules for the rapid construction of a variety
of networking topologies and protocols (e.g., TCP, UDP, multicast, and
HTTP).
- Control of networking bandwidth, latency, and
jitter, referred to as network Quality of Service (QoS).
- Modules for avatar rendering and articulation.
- Connection scalability to allow access to
workstation compute clusters, and connectivity of
small to large numbers of participants.
- Data scalability to provide homogeneous
accessibility to small-to-enormous scientific
databases, and the ability to choose the database performance needed to
support the particular data storage task at hand
- Imbedded capabilities for performance
monitoring so an application can query itself on its
performance.
- A high-level interface that combines networking
with databases so that different Application Programmer Interfaces (APIs)
will not have to be learned and made to inter-operate.
- High-level modules containing pre-built
environments equipped with minimum Tele-Immersion capabilities, which
application programmers may extend to build domain-specific applications.
- Core development issues
- Application programmers should not have to
worry about core technology development
Sample CVE - Cavernsoft
Supports the rapid creation of new
Tele-Immersive applications and eases the retrofitting of previously
non-collaborative VR applications with Tele-Immersive capabilities
- Central structure called the Information Resource Broker (IRB)
- IRB is a relatively low-level merging of
networking and database capabilities separate from graphics
- IRB core can be placed in any software
application regardless of its graphics capabilities
- Permits graphical applications to communicate with
non-graphical applications and allows existing non-collaborative
applications to achieve networking capabilities with minimal disturbance
to their existing graphics
- Surrounded by layers of support software that
facilitate the construction of new components, as well as the
retrofitting of existing applications.
- Non-graphical template libraries support the
coordination of avatars, as well as audio and video data compression
algorithms
- Higher levels facilitate the rapid development of new
Tele-Immersive applications
- Consists of graphical versions of the lower
layer, like OpenGL, Performer, and Video avatar templates.
- Higher level templates can be gathered into
even higher-level, fully functional Tele-Immersion spaces called LIMBO
spaces
- LIMBO spaces provide:
- varying degrees of avatar rendering and
recording
- model importing, distribution, manipulation
and version control;
- and audio/video teleconferencing.
- By using a basic LIMBO space, collaborators
can work in a virtual space immediately.
Sample
Environments
SIMNET
- First standard protocol for distributed interactive simulations
- Large scale networked simulation system jointly developed by the
U.S. Army and DARPA in the late 1980s
- Links tank, helicopter, and airplane simulators into a realistic
"cyberspace battlefield.
- One of the best examples of the power of immersive
computer-based environments.
- U.S. Army still uses SIMNET daily for the training of soldiers and
the evaluation of emerging tactics, doctrine, and weapons systems.
- Much of the modern SIMNET-based training takes place at Fort Knox, KY.
- M1 Abrams tank and Bradley Fighting Vehicle
simulators linked together provide tactical training of armor and
mechanized infantry units.
- Training allows collective combat skills to be
practiced in a realistic environment.
- Leaders, commanders, and staff train command,
control, and tactical movements of platoons, companies, and battalions
under conditions which evoke the stresses of combat and the "fog of
war".
- Practical Issues
- How to fabricate low-cost, high quality
simulators
- How to network them into a consistant,
virtual battlefield
- Project created 11 site testbed
with from 50 to 100 simulators at each site
- Could be entered from anywhere on the network
using a simulator as a portal
- SIMNET Architecture
- Network Architecture
- An object-event architecture
- Modeled the world as a collection of objects
whose interactions are a collection of events
- Objects are the vehicles and weapon systems
that can interact across the network
- Events in SIMNET are messages to the network
indicating a change in world or object state
- A notion of autonomous simulation nodes
- Individual players on the network responsible
for placing packets onto the network to accurately represent their
current state
- Packet recipients are responsible for recieving such state change information and making
changes in their local model of the world
- No Central server - single point failures do
not take the system down
SGI Flight and
Dogfight
- Flight built in summer of 1983
- If you purchased an SGI, it was the program that you showed people
- Networking added in 1984
- Used serial cable between 2 SGIs and ran
at about 7 fps on a Motorola 68000 (1 MIP with about 500 polygons/sec)
- Multicasting added in 1984 over ethernet
- Distributed in network form on SGIs from
1984
- Flight turned into Dogfight in 1985
- Now players could shoot each other
Doom
- Shareware giveaway of 1st level of Doom
- Flooded LANs with packets at frame rate
- Network ability to blast people in 3D created enormous demand for
further 3D networked games
NPSNET-IV
- Capabilities
- Building walkthroughs
- Articulated humans
- Networking
- Terrain database integration, terrain paging
(70km x 70km)
- Any vehicle capability - air, ground,
articulated human
- Interoperability with SIMNET
Dive - 1991
- Internet-based multi-user VR system where participants navigate in
3D space and see, meet and interact with other users and applications.
- DIVE supports the development of virtual environments, user
interfaces and applications based on shared 3D synthetic environments.
- DIVE is tuned to multi-user applications, where several networked
participants interact over a network.
- Dynamic behaviour of objects are described by interpretative Tcl
scripts evaluated on any node where the object is replicated. Script are triggered by events in the system, such as
user interaction signals, timers, collisions, etc.
- Reads and exports VRML and several other 3D formats.
- Integrated with the World-Wide-Web and is HTTP/FTP/HTML/MIME
compliant.
- Applications and activities include virtual battlefields, spatial
models of interaction, virtual agents, real-world robot control and
multi-modal interaction.
NICE - EVL -The
Narrative Immersive Constructionist/Collaborative Environments Project
- Example of a Persistent Tele-Immersive world
- Persistent Tele-Immersion is defined as
collaborative computer-generated worlds that remain extant (i.e.,
continue to exist and evolve) even when there are no human participants.
The ``world'' is a computer generated representation of a computer simulation.
- Applies virtual reality to the creation of a family of educational
environments for young users.
- Based on constructionism, where real and
synthetic users, motivated by an underlying narrative, build persisting
virtual worlds through collaboration.
- Approach grounded on paradigms in contemporary learning and
integrates ideas from virtual reality, human-computer interaction, CSCW,
storytelling, and artificial intelligence.
- The goal is to build an experiential learning environment that will
engage children in authentic activity.
- Constructionism
- Build and develop small local ecosystems on the
bare parts of the island
- Terrain serves as an open land which the child
explores to decide where to plant and populate
- When the user drops a seed on the ground, the
corresponding plant, flower or tree will start to grow
- Plant objects contain a set of characteristics
that contribute to their growth
- Visual cues aid the child in determining the
state of a plant or flower
- Collaboration
- Network architecture allows multiple networked
participants to explore the same virtual space
- Separate VR systems are connected via a
centralized database server that guarantees consistency across all the
separate environments
- Narrative
- Narrative structure captures every action that
is taking place in the form of simple sentences such as: "Amy pulls
a cloud over her carrot patch and waters it. The tomatoes complain that
they didn't get enough water. Claudio plants his first tree."
- Interaction techniques
- Standard CAVE interface device, which is a wand with a joystick and three
smaller buttons for various operations
- NICE Character - Agents and Avatars
Avatars
Agents
Garden Family
Children can plant a vegetable garden
CAVERN: The CAVE Research
Network
- CAVERN, the CAVE Research Network, is an alliance of industrial and
research institutions equipped with CAVEs, Immersadesks, and high performance computing
resources, interconnected by high-speed networks to support collaboration
in design, training, education, scientific visualization, and
computational steering, in virtual reality
- 16 CAVE and Immersadesk sites linked together
in a collaborative VR experiment at Supercomputing '97, held in San Jose, California. Using existing networks and a conference phone call to support
real-time audio, participants from these sites interacted in a persistent tele-immersive environment
CavernSoft
Applications
- The Collaborative Image Based Rendering Viewer (or CIBR View)
- CAVERNsoft-based tool for viewing animated sequences of image based
renderings from volume data
- Allows DOE scientists to view volume renderings
composed of 2D image slices.
- Allows collaboration on a variety of
visualization platforms- from desktop workstations to CAVEs
74 slices of a CT scan of a head
CAVEStudy project
- Enables scientists to interactively steer a simulation from a
virtual reality environment
- Allows interactive and immersive analysis of a simulation running
on a remote computer
Virtual Soccer
Visualization and steering of a molecular dynamics simulation