Toward Collaborative Construction and Design of Interactive Virtual Prototypes

1
Toward Collaborative Construction and Design of
Interactive Virtual Prototypes
The CAVALCADE project
2
Presentation
3
Presentation
CAVALCADE consortium
Partners
CS-SI
AIS
CRS4
IRIT
Partners
Associate Partners
CSTB
SEAT
SNCF
ESA
4
Presentation

• CAVALCADE purpose
• To study Virtual Reality technologies benefits
  for the interactive construction and use of
  virtual mock-ups.
• To develop a simple and intuitive software
  (compared to existing CAD/CAM software) product
  for decision-makers and for other contributors
  not used to computers in earlier project stages
• To support concurrent engineering processes and
  collaborative working

5
Interactive Virtual Prototyping
6
Interactive Virtual Prototyping

• Goals
• To use mock-ups to make good decisions as soon as
  possible, to be able to correct errors as soon as
  possible and at the lowest cost
• assessment, realisation, test and validation
• To avoid physical mock-ups which can be extremely
  expensive and which are not flexible

7
Interactive Virtual Prototyping

• Needs
• A very interactive solution which can be used
  during pilot study phases by people who are not
  CAD gurus or even computer scientists

Traditional CAD/CAM tool
8
Interactive Virtual Prototyping

• Needs
• A tool which may be able to ease communication
  between the different teams involved
• A software base for concurrent engineering and
  remote working
• The use of 3D visualisation and interaction as
  access metaphors to non-graphical information

9
Interactive Virtual Prototyping

• Solutions
• Use of Virtual Reality technologies
• natural man-machine interaction

10
Interactive Virtual Prototyping

• Solutions
• Use of Virtual Reality technologies
• stereoscopic visualisation

Stereoscopic glasses with eye shutters
Head-mounted display
11
Interactive Virtual Prototyping

• Technical solutions
• Use of optimisation techniques for real-time
  rendering
• level of detail generation and management
• progressive meshes

12
Interactive Virtual Prototyping

• Technical solutions
• Use of optimisation techniques for real-time
  rendering
• culling out-of-sight or hidden objects

13
Interactive Virtual Prototyping

• Examples
• FlyThru system
• put at engineers disposal in 1992
• used during the 777 program to fill in CATIA for
  interactive visualisation of large databases
  (40000 models)

14
Interactive Virtual Prototyping

• Examples
• CERNs VENUS project
• based on i3D system developed by CRS4
• used for visualising and assembly planning of the
  Large Hadron Collider

15
Interactive Virtual Prototyping

• Examples

 Gare du Nord  project
ISS interactive prototype project
16
Collaborative Virtual Prototyping
17
Collaborative Virtual Prototyping

• Introduction
• Need for a software platform for data
  distribution among a computer network (DVise,
  World2World, VIPER, HLA RTI, Corba)
• Consistency control of the distributed virtual
  prototype
• Teleconferencing support

18
Collaborative Virtual Prototyping

• Example PROVIS project
• Initiated by the CNES in 1995
• Developed by CS in collaboration with IRIT
• Dedicated to the virtual prototyping of satellites

19
Collaborative Virtual Prototyping

• Example PROVIS project
• Function requirements
• library of prototypes and virtual components
• interactive assembly of these items thanks to
  mechanical links
• interactive manipulation of built mechanisms for
  validation purposes
• component validation depending on domain-specific
  constraints (weight, electrical consumption)
• on-line documentation associated to components
• support for concurrent engineering and for
  collaborative working

20
Collaborative Virtual Prototyping

• Example PROVIS project
• Distributed architecture for co-operative
  working VIPER
•  Desktop VR  multimodal interface

21
The CAVALCADE projecthttp//www.cisi.fr/cavalcade
22
The CAVALCADE project

• Introduction
• CAVALCADE Collaborative VirtuAL Construction And
  DEsign
• Interactive tool for collaborative virtual
  prototyping
• Based on the VIPER system

23
The CAVALCADE project

• Distributed architecture
• VIPER VIrtuality Programming EnviRonment (IRIT)
• Entities wrap application services, graphical
  objects and their behaviours

Virtual Environment
Entities
24
The CAVALCADE project

• Distributed architecture
• Entities may be located on different networked
  machines
• Entities may either be Unique or Duplicated
  entities

Distributed Virtual Environment
machine1
machine2
machine3
25
The CAVALCADE project

• Distributed architecture
• Messages are exchanged by the system in order to
  preserve consistency and to ensure interaction
  between entities

Virtual Prototypes
Stimulus
Stimuli
26
The CAVALCADE project

• Interaction model
• Stimuli (phenomena or events perceptible by an
  entity)
• Stimuli spaces (interaction media, ease
  distribution)
• Effectors (production modification of stimuli)
• Sensors (receive perceptible stimuli)

Entity
Sensor
Stimuli Space
Effectors
27
The CAVALCADE project

• Distributed interactions management
• Orders ( CORBA messages)
• messages, object manipulations, collisions...
• Distributed order space ( CORBA ORB)
• Order routing space

s1
site
Order space
Manipulation order
s2
s3
s4
28
The CAVALCADE project

• Teleconferencing
• A synchronous collaborative application often
  requires transportation of audio and video
  streams in order to keep users in touch
• Encoding a media stream without compression leads
  to a huge waste of bandwidth which can saturate
  the network
• 705 Kbits for 1 second of monophonic Compact Disc
  quality
• 8 Mbits for 1 second of video at 352288 at 10 Hz

29
The CAVALCADE project

• Teleconferencing
• VIPER has audio/video compression features in
  order to reduce the flow on the network gt
  encapsulated into Stimuli
• GSM compression for audio

Original sound 705 Kbits/second
Compressed sound 13 Kbits/second compression
time 30 ms
30
The CAVALCADE project

• Teleconferencing
• MJPEG for video threads encoding

(M)JPEG compressed image 128 Kbits/second at 10
Hz compression time 40 ms/image
Original image 2 Mbits/second at 10 Hz
31
The CAVALCADE project

• Architecture
• CAVALCADE is defined by 4 types of entities
  (CS-SI)

32
The CAVALCADE project

• Avatars teleconferencing module

Video reception for user 1
General video emission
General audio emission
General audio reception
Dialog with computer
Teleconferencing groups management
Audio emission to user 1
Audio reception for user 2
Microphone sensitivity
Volume setting
Video emission to user 1
User 2 colour
33
The CAVALCADE project

• Avatars visualisation module (CS-SI VERTIGO
  library)

34
The CAVALCADE project

• Avatars GUI module

35
The CAVALCADE project

• Architecture the Builder
• Cavalcade modelling features

Builder entity
Device orders
Dialog management module
ltcommandgt
Interpreter module
Orders
36
The CAVALCADE project

• Builder dialog module
• In charge of multimodal dialog management
• several expression modalities may be combined to
  form a command
• references to deictics ( this ) are resolved by
  this module

 Put this antenna
on this 
Speech
Time
tp4
tp5
tp1
tp2
tp3
tg2
tg1
Gesture
Time
entity  antenna  click
2nd entity dick
37
The CAVALCADE project

• Builder interpreter module
• In charge of command execution
• Fuzzy operator management move it to the
  right 
• object size function
• command history function
• Commands
• Primitive creations, 3D objects CAD models
  import (IGES, DXF, 3DS, VRML) and model
  simplification (CRS4 progressive meshes)
• Moving, rotating and stretching objects
• Mechanical links definition
• Enabling/Disabling collision detection/avoidance
• Path definition

38
The CAVALCADE project

• Architecture the Expert
• Definition of object classes (name, colour,
  attributes)
• Assigning classes to objects and defining domain
  specific attributes (weight, power consumption)
  
• A shell for CAVALCADE customisation
• Could be in charge of checking the coherency and
  the validity of a prototype thanks to
  domain-specific rules (what an expert is supposed
  to do)
• Could allow data input from external sources
• ...

39
The CAVALCADE project

• Architecture prototypes
• 3D objects handled by the users

Prototype Entity
Interpreter module
Orders
Orders
Sound
Access rights
Documentation
3D shape
http//kiswa/doc.html http/kiswa/son.wav http//k
iswa/note.txt
Doc. Sound Note
A E M V
Paul Paul Designers ANYBODY
40
The CAVALCADE project

• Visualisation
• Horizontal/L-shaped stereoscopic interactive
  device with head tracking (AIS)

41
Conclusions Future Work
42
Conclusions Future Work

• Conclusion
• We have presented the technical basis necessary
  for co-operative and interactive virtual
  prototyping
• Some tests have been made to assess the ergonomic
  quality of our system
• Force feedback is an essential vector of
  information which is still missing for a good
  man/machine interaction
• Such a system does not replace CAD tools but
  fills them in for pilot studies

43
Conclusions Future Work

• Conclusion
• The first release of CAVALCADE is available and
  being tested by end-users
• Former internal use of such tools for virtual
  mock-up construction has enabled us to validate
  the interactivity of our solutions

44
Conclusions Future Work

• Future work
• Interoperability with CAD tools
• CAD ð VR to improve (currently IGES, DXF, 3DS,
  VRML) gt CATIA, STEP...
• VR ð CAD to realise
• Customisation for architecture design
• Integration of realistic rendering effects (real
  time reflexion and shadow casting, radiosity
  lightening)
• Integration of crowd simulations
• Customisation for space industry
• Acquisition/Display of data from external systems
  (hardware simulators)