1. 1VG99 Volume Graphics and the Internet Ken Brodlie and Jason Wood School of Computer Studies University of Leeds

2. 2VG99 Internet n The Internet brings connectivity n Connectivity means… – humans can collaborate – systems can collaborate

3. 3VG99 Why Collaborative Visualization? n Visualization IS a collaborative activity! n Scientific research is carried out in multi-disciplinary teams – each person brings individual skills – teams may be geographically distributed n Influence of the Internet and Web – collaborative culture n BUT existing visualization systems: – single user model and pre-Web

4. 4VG99 How Can We Collaborate? n General application sharing – one host acts as master, broadcasts screen display to other participants – collaboration at the operating system level – SharedX, MS NetMeeting – high bandwidth requirement n Collaborative visualization systems – use knowledge of application to get a better solution

5. 5VG99 Collaborative Visualization - Outline of First Part of Talk n Influences – other work on collaborative visualization n Concept – linked dataflow n Realisation – IRIS Explorer COVISA toolkit n Application – collaboration in volume visualization

6. 6VG99 Tempus Fugit - Sharing Geometry n CFD visualization system developed by Michael Gerald-Yamasaki at NASA Ames - Eurographics 93 Simulation Visualization supercomputer Geometry list workstation Rendering workstation Interview

7. 7VG99 ONERA - Sharing Control n In the EU PAGEIN project, Michel Grave at ONERA developed a ‘shared interface’ approach above n Parameters to be shared extracted into a shared interface above the visualization system

8. 8VG99 CSpray - Collaboration Issues n Extension of Alex Pang’s Spray rendering n Particles fired into data with specific objective - eg locate isosurface n In CSpray, each person has a spray can n Careful study of issues – floor control – privacy – audit trail

9. 9VG99 COVISA Research Objective n Our aim was to evolve a collaborative extension of Modular Visualization Environments – IRIS Explorer, AVS, IBM Data Explorer, Khoros – usability: – usability: keep same metaphor – sharing: – sharing: share data and control with other participants – flexibility:program – flexibility: program the collaboration to allow network efficiency, privacy, join-at- any-time

10. 10VG99 We have this...

11. 11VG99 … we want this

12. 12VG99 Back to the Visualization Reference Model n To design a collaborative visualization system, we return to the underlying Haber-McNabb reference model - and think how to extend it: FILTERMAPRENDER INPUT DATA simulation measurement geometry (surface/volume) image filtered data

13. 13VG99 Collaborative Dataflow Model FILTERMAPRENDER INPUT DATA FILTERMAPRENDER INPUT DATA

14. 14VG99 Collaborative Dataflow Modules FILTERMAPRENDER INPUT DATA ADVISOR Internet FILTERMAPRENDER INPUT DATA SHARE PARAM SHARE DATA

15. 15VG99 Use My Network... ADVISOR FILTERMAPRENDER INPUT DATA Internet FILTERMAPRENDER INPUT DATA senior scientist junior scientist

16. 16VG99 See What I Can See... FILTERMAPRENDER INPUT DATA ADVISOR Internet FILTERMAPRENDER INPUT DATA SHARE PARAM senior scientist junior scientist

17. 17VG99 See What You Can See... ADVISOR FILTERMAPRENDER INPUT DATA Internet RENDER SHARE DATA

18. 18VG99 Do Your Own Thing... ADVISOR FILTERMAPRENDER INPUT DATA Internet MAPRENDER SHARE DATA

19. 19VG99 Can I Use Your Expertise? FILTERRENDER INPUT DATA ADVISOR Internet SHARE DATA MAP SHARE DATA

20. 20VG99 IRIS Explorer COVISA Toolkit n This research is now available as the COVISA add-in to IRIS Explorer n Advisor, ShareParam, ShareData modules... n...wired in to networks exactly like any other n See IRIS Explorer Centre Web Site: – http://www.scs.leeds.ac.uk/iecoe

21. 21VG99 COVISA Architecture

22. 22VG99 Starting a Session

23. 23VG99 New Modules

24. 24VG99 Advisor Module

25. 25VG99 Collaborative Modules n Modules can be written as directly collaborative – for example, MSharePointer

26. 26VG99 Collaborative Applications n End-user applications can be built as a layer on top of a dataflow network – selected parameters exposed to users in a simple interface – collaboration can be included in these

27. 27VG99 Application n Video will show application to volume visualization n Radiologist studying abdominal aortic aneurysm.. n … collaborates with a medical physicist with segmentation skills

28. 28VG99 The Story Begins With...

29. 29VG99 Web-based Visualization

30. 30VG99 Visualization and the World Wide Web descriptive n Early use for descriptive visualization – visualize using conventional software such as MVEs – publish as an image, or as 3D VRML model analytical or exploratory visualization n Now used also for analytical or exploratory visualization – visualization process executed as a Web- based application n Web-based visualization has become an established branch of discipline

31. 31VG99 How Did It Start? n Pioneering work by Ang et al 1994 client-side – medical volume visualization system VIS used as a client-side application linked to Mosaic browser – invoked on receipt of MIME-type ‘hdf/volume’ n Server-side example from Wood 1995 – air quality visualization service server – IRIS Explorer on server, returning VRML n Now many styles of web-based visualization client-basedserver-based – some client-based, some server-based

32. 32VG99 Client-based Systems n Action is at the client n Three flavours according to what is sent from the Web server: – raw data – script to drive software – software Web server Browser

33. 33VG99 Sending data - Vis5D n Vis5D: for meteorological visualization, from Hibbard at Wisconsin n Configured as helper application, invoked on receipt of MIME- type ‘application/vis5d’ n Daily weather forecasts

34. 34VG99 Sending a Script : Client- Explorer n Client-based system with IRIS Explorer developed by Alan Yeo and Jason Wood at Leeds n Set of instructions downloaded from server to ‘program’ IRIS Explorer on the client n Instruction file invokes application which drives IE

35. 35VG99 Sending Software : VizWiz n VizWiz is Java applet for volume visualization, from Michaels & Bailey at SDSC n Data is a problem: must be uploaded from client to server to work around Java security issues

36. 36VG99 Server-based Systems n Action is at the server n Three flavours according to what is sent from the server: – 3D graphics – 3D graphics plus software – images / video Web server Browser

37. 37VG99 Sending VRML : Air Quality Visualization Service n Air quality web- based visualization system with IRIS Explorer on server, developed by Jason Wood n User completes form saying what data, and what technique n CGI script invokes IRIS Explorer n VRML returned

38. 38VG99 Sending VRML and Java: Isosurfacing n Engel and colleagues at Erlangen have implemented their progressive isosurface algorithm as a web-based system

39. 39VG99 Sending VRML and Java: Volume Rendering n Texture-based volume rendering can be delivered as VRML n This VRML volume rendering developed by Nigel John and colleagues at SGI Biomedical n Java applet provides interaction

40. 40VG99 Sending Images/Video: Volume Render n Rather than render on the client, it is possible to render on a server and ship the images to the client… n … this approach has been used by Stredney et al at Ohio for remote volume rendering n Client uploads data to server (with 3D texture hardware)

41. 41VG99 Review n Client-based – high interactivity – needs software availability at client, plus skill to use it – needs compute power at client… but this is dedicated n Server-based – low degree of control – software provided by server – compute power provided by server … but shared between many

42. 42VG99 Extending to Collaborative Web-based Visualization n Both client and server based systems can be extended to collaborative style of working - although surprisingly little work has been done in this area

43. 43VG99 Client-based Systems n FASTexpeditions can run in a pilot- passenger mode n ClientExplorer can be extended to incorporate the COVISA shared modules n VisAD has been used in a collaborative setting, with NCSA Habanero

44. 44VG99 Server-based Systems n Air quality visualization service (IRIS Explorer on server) has been extended to support asynchronous collaboration

45. 45VG99 Collaborative Web-based Visualization n Future direction could be combination of synchronous collaboration provided by the extensions of MVEs described earlier n …and the asynchronous collaboration for which the Web is well suited, providing a sustainable environment for collaboration

46. 46VG99 Base Software Input Data Design Setup Script Reference Model - The Processes Render CSC S C C

47. 47VG99 Client-based Systems n Design executed on client-side Base Software Data SetUp Design Script RenderC

48. 48VG99 Vis5D n All components except the data are resident on the client, and executed on the client Base Software Data SetUp Design Script Render C S C CC C

49. 49VG99 FAST Expedition n FAST: CFD visualization system from NASA Ames n Setup and script can be downloaded from server - so a guided tour is possible

50. 50VG99 FAST Expedition n Distinguished from Vis5D because system ‘SetUp’ and ‘Script’ driven from server n Client can take over the ‘driving’ - hence Script is Client or Server based Base Software Data SetUp Design Script Render C S S CC CSCS

51. 51VG99 Client-Explorer n Distinctive in that ‘SetUp’ and ‘Script’ can be either client or server driven n Potential application for – education – bureau services Base Software Data SetUp Design Script Render C S CSCS CC CSCS

52. 52VG99 Java Applet Approach n Key feature is base software on server, but execution on client Base Software Data SetUp Design Script Render S S S CC C

53. 53VG99 VisAD n VisAD is novel Java based system from Hibbard at Wisconsin n Idea of linked objects - data objects linked to user interface objects etc n Objects are Java classes that can reside at any URL

54. 54VG99 VisAD n Software can be resident either on client, or a remote server Base Software Data SetUp Design Script Render CSCS C C CC C

55. 55VG99 Server-based VRML Approach n Server-side execution, with client-side rendering n Setup determined by client Base Software Data SetUp Design Script Render S S C SC S