Search
This was the title of the workshop held at the end of November at Cosener's House, Abingdon. This is a very pleasant setting by the river for 3 days work. 33 people from 20 different institutions participated in the workshop and although 23 papers were presented, there was plenty of time for discussions. The workshop report is available as AGOCG Technical Report 24.
A report of the event is given inside this Newsletter. The main results recognised the need for support to underpin the communities increasing use of multimedia. This suppport is likely to be most efficiently provided through the appointment of a Support Officer who would run a helpdesk, run courses, disseminate information etc. It was also agreed that the community needed advice of hardware and software and best practices. This should be carried out by a series of short term projects which were timely. Any funds for this being spent in small chunks with work being done by relevant experts.
One important thing is to ensure that there is no overlap between work carried out by AGOCG and other initiatives. The Support Officer could play a vital role in working with other initiatives to ensure that this does not happen.
This event is aimed at support staff wanting to learn more about current directions, software deals, exchange ideas, meet other support staff, escape from phone and email for 2 days.
The event is being supported by the Joint Information Systems Committee through its grant to AGOCG. The cost will be £45 plus VAT to members of UK HE institutes.
Many evaluations and deals have focused on the scientific side. I intend to call a meeting in the Easter vacation to bring together people in the areas of graphic art and design to find out what their needs are and what AGOCG and other community organisations can do for them. If you would like an invite, or know someone who would then let me know.
If you have any thoughts on this or would like to make any proposals to ACOCG then please let me know. The next meetings are on 9th March and 28th June.
Why are there three encodings for CGM and how do I know which one to use?
A CGM can be encoded as Binary, Character or Clear Text. Each encoding was designed to satisfy different requirements. The Character encoding is concise and only uses the ASCII printing characters. This ensures that it can be transmitted over any networks. It does, however, require more processing to generate and interpret a character encoded metafile. The Binary encoding is easier, and thus quicker, to generate and interpret on most computers and it is fairly concise. But because it uses 8 bit bytes it causes problems for some networks. The Clear Text encoding is human readable. It is not at all concise but has the advantage that it can be edited with a normal text editor.
A metafile in one encoding can be translated to another encoding with no loss of information. A number of graphics packages can read in a CGM in one encoding and output it in another. There are also graphics utilities, such as RALCGM, which will convert from one encoding to another.
In practise one rarely encounters a CGM in anything but the Binary encoding. If no encoding is specified for a CGM then it is most likely to be Binary encoded. These files often have the .CGM or .BIN extension. Even though many networks still cannot handle binary files it is now common practise to encode/ decode binary files for transmission over such networks. Unencode/ decode and Binhqx are common formats. The combination of the Binary encoding and the encode/decode utilities largely satisfies the requirement that the Character encoding was designed to satisfy. Consequently the Character encoding is not often encountered these days. Clear Text encoded CGMs tend to be used only as a debugging aid, not for the actual transfer of graphics.
Many applications which generate or interpret CGM files do not offer a choice of encoding. They assume the Binary encoding. If, when creating a CGM file, a choice of encoding is offered then you should select Binary encoding, unless the user who will interpret the CGM has specifically requested one of the other encodings.
A revised set of workbooks for Cricket Graph and Cricket Presents (both PC and Mac), and a new workbook for Micrografx Draw! for pc, are now available.
The specific versions covered are:
| Package | Version | System |
|---|---|---|
| Micrografx Draw! | 1.0 | Microsoft Windows |
| Cricket Graph | 1.3 | Microsoft Windows |
| Cricket Presents | 1.5 | Microsoft Windows |
| Cricket Graph | III | Macintosh |
| Cricket Presents | 2.1 | Macintosh |
The workbooks are designed to provide a step by step introduction to the basic facilities of the packages involved. The work to produce the new workbooks, which was funded by AGOCG, was carried out by Computing Services at the University of Edinburgh.
Machine readable postscript copies of the workbooks can be obtained via anonymous ftp from unix.hensa.ac.uk. The files are in compressed tar format and are located in the directory /pub/misc/agocg/workbooks. The index file gives details of the contents.
Master (paper) copies of the workbooks can be obtained at a cost of £15 each from Marie Cope, Graphics Workshop, EUCS, Edinburgh
This is the report of the Workshop on the theme of Multimedia in Higher Education: Portability and Networking organised by the Advisory Group On Computer Graphics (AGOCG - an initiative of the HEFC's Joint Information Systems Committee). This was held on 29th November to 1st December 1993 at the Cosener's House, Abingdon, UK. 33 participants from 20 different institutes in UK Higher Education attended. A total of 23 papers were presented in plenary and group sessions with considerable time set aside for discussion of the issues raised and for recommendations to be agreed.
The very nature of multimedia means that the issues discussed and the recommendations made are wide ranging and it is the intention of AGOCG to ensure that other initiatives in UK Higher Education (for example, New Technologies Initiative, CTI, ITTI, TLTP, NISS) are appraised of the recommendations. AGOCG will be looking to work with other groups in carrying out the proposals from the workshop. AGOCG will be seeking funding to ensure that those recommendations that lie within its remit are carried out.
Multimedia is a collection of technologies that have wide applicability and can now be economically integrated. It is technology which will be industry driven and there is a need for the UK Higher Education community to respond to the growth by actively coordinating its activity to maximise the effective and efficient use of this key technology.
Multimedia includes a range of components: images, video, text, sound, voice and a rich range of inpu t devices. These require integration and synchronisation. The skills required for this are wide and the experts in the community need to work together to maximise the benefits of the technology.
Multimedia has a wide range of applications. The major ones identified at the workshop being in teaching and learning situations, cooperative working, visualization and in the provision of information resources.
Within UK Higher Education we have seen a commitment to multimedia in training, teaching and learning through initiatives such as CTI, IITI and TL TP. The use of IT in teaching is also one of the criteria being used in the teaching quality assessment. Information resources are also being funded through initiatives such as NISS and NISP, though the use of media beyond text is very limited at this point in time. The Follett report on Libraries in UK Higher Education (due out at the end of 1993) is expected to make recommendations regarding the use of information technology in libraries and in document delivery.
Multimedia is important for both passive teaching and in active teaching. It enables teachers to take advantage of a wide range of resources and to assist the student in effective learning by choosing the right set of delivery vehicles for imparting knowledge. The use of multimedia materials may enable the widespread use of rare resources. These resources may be rare manuscripts, medical images and operations, the teaching staff themselves who may be geographically distant from students and/ or few in number in specialist areas. The student can be highly motivated to use multimedia materials (a transfer of motivation from use of computer games).
Multimedia provides capabilities for discovery, access and distribution of a wide range of resources. These may be images, soundclips, animated sequences, fully authored packages, journals, online conferences.
Multimedia data is also crucial to many fields of research, including applied research in medicine and engineering.
Current work is only beginning to scratch the surface of the potential of multimedia as a key new technology. Many of the applications require some form of underpinning to avoid unnecessary duplication of effort and to ensure that experience is rapidly circulated within the community. This is particularly important given the projected very rapid growth in the availability and use of this technology. The advice required ranges from choice of equipment, authoring software, availability of material, to effective linking of media by providing guidelines.
The key recommendations are:
In March when the advert went out, I wondered whether I had done the correct thing in persuading Advisory Group on Computer Graphics (AGOCG) and my boss to fund 7 students to work on visualisation and related topics in the CGU over the summer. Would anybody apply, could we think of the right projects, would they all fit in, both socially and physically, did we have enough resources for them to work,...?
I guess I should have known better when on the closing date we had over 214 applications for 4 of the posts. From then on the pace never seemed to slow down. The students we employed demonstrated fantastic enthusiasm, commitment, ability and dedication. However the other highlight of the period for me was being summoned out of a meeting with very senior MCC staff and Thinking Machines Corporation, to rush home to collect Jan (my wife), to rush back to St Mary's Hospital, to witness the arrival of Sam Peter Hewitt, some 5 hours later. Both the students and Sam Peter have made it a summer to remember.
Of course I did not do it all myself! All of the CGU staff were actively involved in supervising students: Tony Arnold, Yien Kwok, Andrew Grant, Steve Larkin, David Yip, Chris Lilley, Un Fenqiang. I must also thank the MSc and PhD students who also helped significantly: Dean Gammage, David Hutchinson, Martin Preston and Neil Gatenby.
As usual last, but not least a big thanks to Mary McDerby, from all of us. She keeps us all supplied with happiness and coffee, and somehow manages to find the time to do her own work.
The output of each student far exceeded our expectations, and they developed (in summary):
Much of this will be available directly to the academic community.
Well I guess not only am I crazy, but so are my bosses (Louis Blanchet and Ron Chisnall) and AGOCG, because we have all agreed to do it again! The advert for the posts will appear round about Easter time.
As an additional feature we will introduce a series of lectures from members of the CGU Staff and some external notables, to the students covering a number of hopefully interesting topics. These lectures would be advertised more widely and open to anyone to attend.
There will be one feature removed from next years programme: No more children for me!
Helen is a mathematics graduate of UMIST. Subsequently she has been appointed to replace Mr D Yip on the CGU Staff. Recently the CGU purchased, with funds from the Supercomputing Management Committee, a colour A0 PostScript plotter: the NOVAJET. This is a 300 dpi ink jet printer, which is front ended by a PC running the freedom of the press PostScript interpreter. The central printing software expects to be able to communicate directly (through LAT, TCP/IP or terminal lines) with the printer. This was not possible with this new configuration.
Helen designed, implemented and documented a system for spooling documents sent to an OpenVMS print queue to the NOVAJET large format PostScript printer connected to a PC in the CGo. The system is sufficiently general that the software could be used for other output devices such as the 35mm slide production facilities in the Staff Development Unit. Ownership of documents printed on the NOV AJET should be easily identified. In addition accounting information must be saved. The system consists of the following parts:
This software is now undergoing field tests and will be released soon.
Alex is just about to enter his second year in the Department of Computer Science at the University of Edinburgh.
In May the CGU had installed some equipment for creating video tapes from a sequences of images. To use this facility the CGU had developed:
Videoprint: a program which accepts instructions on how to lay a number of images onto tape. It supports TIFF, RLE, SGI, and PBMPLUS format images, and a number of interpolation effects for scrolling titles, fading from one image to another, and linear interpolation between images. A prototype AVS module to place AVS images onto video tape for a defined number of frames at a specified position.
Alex extended Videoprint and developed a fully functioning AVS module suite:
In addition, Alex produced a document describing how to make video tapes and MPEG movies from AVS, and finally with Paul made some movies.
Apart from Create Video which is specific to the hardware configuration at the CGU these modules will be placed in the public domain.
Emily has just graduated in English from the University of Newcastle. Note that this project was only 7 weeks.
Emily produced a number of publicity documents for the CGU, so that our facilities and services can be ad vertised around the University and UMIST campus and also to external academic and commercial sites.
In summary, the brochures are:
They can be obtained from MXX and/or the CGU.
Andrew has just completed his 2nd year in the Department of Computer Science, University of Manchester. We have been testing a beta version of AVS on the Meiko Computing Surface, the local parallel processing facility. It became clear that additional teaching materials were needed if other people were to avoid the struggle of using AVS in this 80 processor environment.
Andrew developed a self-help tutorial for using parallel AVS on the Meiko. He developed a sample application based around the edge detection algorithm. This was chosen as it would be easy to understand by all. It shows how to write an simple parallel AVS module (executing on the Meiko, while AVS executes either on the Meiko, or for example, a HP workstation) using the CS Tools parallel communications library. A detailed self-help tutorial document has been prepared by Andrew and will be issued shortly, as an MCC document.
Matthew has just graduated in geology from the University of Durham. The aim of this project is to demonstrate the use of AVS in geology and related sciences. Matthew has produced a separate article in this edition of the newsletter.
Paul has just graduated in Computer Science from the University of Manchester. His main role was to produce examples of various techniques in scientific visualization, for educational purposes. The examples were produced on 35mm slides, PHOTO-CD and video tape. These examples will be distributed nationally as part of the ITTI project to produce training materials in Computer Graphics and Scientific Visualisation. This project is hosted at the University of Manchester and these materials form part of a module being developed in conjunction with AGOCG.
By the end of ten weeks Paul had produced a number of slides and over 5 minutes of video, demonstrating, among other things: animation of medical imaging data and Venus topography, aliased and antialiased text, the effects of Alex's video modules, i.e. gamma correct and video hot colours and the effect of low-pass filtering. In addition improved the AVS image-to-postscript module.
Alex has just completed the 2nd year of a Mathematics course at the University of Manchester.
GHOST-80 provides unparallelled Matthew Hall facilities for the production of two dimensional graphs. It has been primarily used for this purpose for the past twenty years. The aim of this project is to provide a cookbook for the conversion GHOST-80 to UNIRAS/FGL. The philosophies of GHOST-80 and UNIRAS mean that there is not a one-to-one mapping of subroutines. There is, however, a one-to-one mapping of GHOST-80 and UNIRAS concepts: Mapping between user/world coordinates and plot/device coordinates, Axes/Scales, Grids, Axes/Scales ticks/labels/ annotations, Titling/legends, and Contours/surfaces (isolines not filled). The approach in the cookbook is not a list of GHOST routines and corresponding equivalents in UNIRAS because that would be too time consuming to create. Instead the mapping from GHOST to UNIRAS is at the level of example programs, each illustrating a common GHOST graphics task, e.g. plotting a log-lin graph of a function with axes and graticule.
Each of the above concepts is illustrated by example GHOST-80 programs on the left-hand pages with corresponding example UNIRAS FGL/Graphics programs on the right-hand pages. The examples are in Fortran 77. Each UNIRAS program is explained with references to the UNIRAS documentation.
An appendix details the conversion of a non-trivial GHOST program provided by Dr A Nasser to UNIRAS. The cook-book addresses the vast majority of realworld applications of GHOST and shows how to implement them in UNIRAS.
The cook-book is now available as document MCM 601.
A further article on AVS and Geological Applications of AVS by M Hall and W. T. Hewitt will appear in the next issue.
Part 2 (Part 1 was contained in Graphics & Visualization Newsletter No 32)
Visualization 93 took place 25-29 October 1993 in San Jose, California, and attracted 560 delegates to the week's programme of Tutorials, Panels, Papers and Case Studies. It was also held in conjunction with the first Symposium on Research Frontiers in Virtual Reality, 25-26 October, and a Symposium on Parallel Rendering.
The Conference consisted of Paper Sessions, Panel Sessions, and Case Studies.
The paper sessions consisted of contributions in the technical areas of volume visualization, flow visualization, visualization environments, visualization techniques and algorithms, visualizing databases and parallel programs, human factors in visualization, textures and shading, and visualization applications in the sciences - 41 papers in all. There were 6 Panel and 14 Case Study papers in the theme areas of oil and CFD, high energy physics, the environment, medicine and archaeology. Case Studies were technical presentations oriented towards the application of state-of the- art visualization techniques and facilities in this wide range of application domains. Generally papers, panels, and case studies were all in parallel.
This report concentrates principally on the Panel Sessions, since the proceedings contains the technical detail presented in the papers.
The Keynote Panel on Visualizing the Environment, Visualization in the Sciences, and Visualizing the Universe was chaired by Prof Gregory McRae of MIT. He described the role of high performance computing, visualization, and data management in representing and analysing the environment. Data storage, display, and interpretation are vital to environmental problem solving. What are the best ways to grow the economies of developed countries without impacting on the environment? Control of air pollution in the USA is becoming a major issue. 80-100 cities are currently not in compliance with the regulations. The federal government has made $30 billion per annum available for pollution controls, and $200 billion on environmental issues, e.g. designing control strategies. Current studies are complex, with 12000 mesh points, 30 chemicals, and 500,000 state variables. What are the best ways to communicate the results of these investigations to those who determine the policy? The work also needs to be translated into terms that can be understood by a wider audience. Scripts were needed in order to make presentation videos quickly. Videos that were going to be used for presentations to public audiences, or busy people, need careful preparation. The film and art community know how to capture the public imagination (e.g. TV programmes) and it is a nontrivial task for the amateur to produce a presentation of quality which does full justice to the technical quality of the material. Colour needs to be used carefully, and artists' advice should be sought.
Geographic environment modelling systems involved global and detailed views, distributed object-oriented databases, heterogeneous computing environments, interfaces tailored to probes, analysis and display.
In summary, what was needed was an integrated view of data display and analysis, links to GIS with analysis, high performance computing, and a new approach to environmental decision-making.
Prof Margaret Geller, Harvard University, used graphics and visualization to study the distribution of galaxies in the universe and also to present the information on video.
Applications in Virtual Environments: Bridging the Gap between Prototypes and Working Tools discussed current VR technology and the range of possible applications where current tools were useful. The best known attribute of VR is the sense of presence or immersion; this distinguishes VR systems from multimedia or interactive computer graphics. Understanding the nature of presence is still at an early stage.
Prof Steve Benton, Spatial Imaging Group, MIT, outlined current work on quasi holographic virtual environments. Steve Bryson, CSC/ NASA Ames, explained why applications development was currently so hard
which requires powerful and advanced equipment. Currently displays are uncomfortable, trackers are inaccurate, haptics is a research area, but some progress is being made with sound. The computational power is insufficient to support all but the simplest environments. Graphics performance is limited (currently around 2 million triangles/ sec, which equates to 200K triangles/ frame, or 100 objects with 2000 triangles each - if the triangles are small).
There are also data management problems. Data is needed within 0.1 sec. For many applications this is not a problem, but for some applications it is a serious problem; disk bandwidths are too small, and data latencies too large. Human factors are largely unknown, and immersion and task performance in VR are poorly understood. There is a lack of software models: event-driven interactive computer graphics breaks down in VR, long tasks slow down the overall system, multiple concurrent asynchronous processes have the best performance. There is a lack of applications theory: very few nontrivial application examples, no predictive theory, no criteria for which applications make sense in VR, difficult to construct non-trivial applications, and there is a need for rapid proto typing capability. However, applications are being designed: compromises enabled the designer to work around performance constraints, human factors can be improved, and it is best to work with an interdisciplinary team where the scientists are involved in the development of the application.
Prof Mark Green, University of Alberta, outlined experiences of developing the MR software toolkit, and its use in 130 sites over 2 years. What features should Virtual Environment (VE) tools support? There is a tension between three dimensions of the problem:
and deciding which is the best combination.
Prof Randy Pausch, University of Virginia, outlined the experinces of developing DIVER. Small tiger teams are best for developing applications. 1-2 computer scientists/engineers and 1-2 more creative people. User acceptance of VR depends upon more user-friendly interfaces rather than heavy helmets.
Key application areas were felt to be entertainment, communications (CSCW), and simulation. Eventually internet and Xmosaic might be used to navigate through other people's data (e.g. DNA applications).
The Panel on Visualization Reference Models looked at the benefits and problems of developing models.
Is Visualization really Necessary? The role of Visualization in Science, Engineering, and Medicine examined a number of key application areas. The Boeing 777 aeroplane is being designed and built using computer and visualization methods. The benefits are improved design, solution of integration issues, and a catalyst for new ideas.
Prof Robert Langridge summarised the progress being made in the utilisation of visualisation in molecular biology. Prof J. D. Pearlman, Harvard University, outlined the use of visualization tools in medicine to
A project on Teleradiology Diagnostic Exchange enabled simultaneous display of radiodiagnostic image and text data on multiple terminals, access across TCP /IP, interactive cursor display and control.
The Capstone Address To Understand Visualization it helps to understand Vision was given by Prof Stuart Anstis, University of California at San Diego.
There was a report on the international ONR sponsored workshop on Data Visualization: Research Issues, Applications, and Future Directions held in Germany in July 1993. The results of this workshop are being published in IEEE Computer Graphics and Applications, March 1994, and in a book "Frontiers of Scientific Visualization", Eds L. J. Rosenblum et a!, to be published by Academic Press, June 1994.
(the next issue will continue with an account of the VR Symposium Research Frontiers in Virtual Reality).
