No Subject

Date: Thu, 27 Jan 1994 11:27:18 +0000 

From: Lou Burnard <lou at vax.ox.ac.uk>

>I would like to see a graphics composition language which allows a structured  
>display to be composed on the screen from a number of items, which may be
>local or remote.  For example, I would like to see a chess screen made up
>There will be those who suggest adapting PDF, which is basically
>There will be those who suggest augmenting TIFF, using its general
>There will be those who say it should be SGML.
>There will be those who say that HyTime ought to be used for this,
>There will be those who feel like writing it in an afternoon from
> scratch.


Actually, I think most graphics people would say it should be CGM.
Indeed, I think there are some who would say it *is* CGM. 

But I am no expert in this field...

regards

Lou


From: Dave_Raggett <dsr at hplb.hpl.hp.com>

Date: Thu, 27 Jan 94 15:42:24 GMT 

I too have been putting thought into a similar scheme. It seems to me
that the processing power of workstations and high end PCs is now
good enough to support platform independent VR with Web style global
hyperlinks. Like Tim, I believe that the way forward will naturally lead
to non-proprietary VR, and think now is the time to start exploring
how we can do this.

A key to allowing effective platform independence is to use logical
descriptions so that viewers can fill in the details according to their own
rendering capabilities. As an example, you could describe a room in terms of
the polygon defining the floor plan, the height of the walls, and categories
for the textures of floor, walls and ceiling. Hierarchical descriptions of
wall textures could include: raw color and a link to the tiling pattern for
an explicit design of wall paper. Low power systems would use plain walls,
saving the cost of retrieving and patterning the walls. Fractal techniques
offer interesting possibilities too.

Shared models would avoid the need to download detailed models, e.g. for
wall paper, window and door fittings, chairs, tables, carpets etc. These
models, by using well known names can be retrieved over the net and cached
for subsequent use. The models would include hierarchical levels of detail.
This is important for "distancing" and reducing the load on lower power
clients. In addition to appearence, models could include behaviours
defined by scripts, e.g. sound of a clock ticking, the way a door opens
and functional calculators, radios and televisions.

Full VR needs expensive I/O devices, but we could get by with side-ways
movement of the mouse (cursor keys) to turn left or right and up-down
movement of the mouse to move forwards and backwards in the scene. I believe
that allowing a progression from simple to sophistocated I/O devices with the
same VR interchange formats will be critical to broad take up of VR.

So far I have outline a way in which you could click on an HTML link and
appear in a VR museum and wander around at will. Pushing on doors would
correspond clicking on hypertext links in HTML. The next step is to get to
meet other people in these VR environments. The trick here, is to wrap
real-time video images of people's faces onto 3D models of their heads.
This has already been done by a research group at ATR in Japan. Our library
couldn't find any relevant patents, so it looks like there are no problems
in defining non-proprietary protocols/interchange formats for this approach.

The bandwidth needed is minimised by taking advantage of the 3D models
to compress movements. By wrapping the video image of a face onto a 3D model,
you get excellent treatment of facial details, as needed for good non-verbal
communication, while minimizing the number of polygons needed.

The effectiveness of this approach has been demonstrated by Disney who
project video images on onto a rubber sheet deformed by a mask pushing out
of the plane. Needless to say, there remain some research issues here ...

The first steps in achieving this vision is to start work on a lightweight
interchange format for VR enviroments and experimenting with viewers
and http. A starting point is to pool info on available software tools
we could use to get off the ground.

Regards,

Dave Raggett (looking forward to the Web's VR version of the Vatican Exhibit). 

-----------------------------------------------------------------------------
Hewlett Packard Laboratories,           +44 272 228046
Bristol, England                        dsr at hplb.hpl.hp.com


From: vinay at eit.COM (Vinay Kumar)

Date: Thu, 27 Jan 94 11:07:43 PST 



Very interesting indeed. Recently i saw a running demo from General Magic's
"MagicCap" UI environment. It seems to do a lot of the stuff mentioned by others on
this list earlier (assuming i understand the emails correctly ofcourse). MagicCap UI
shows a downtown view on the desktop, using a mouse one could navigate (VR style)
around houses, rooms, hallways, libraries, etc...One could customize wall colors, wall
papers, posters, and other artifacts in and outside the rooms. Drag and drop feature is
supported. Linking of objects is thru drag and drop. However i am not sure if linking
of objects over distributed networks is supported. They claim everything in their
environment is an "object" and almost every object could be linked to any other
object. I will recommend everyone on W3 to atleast take a look at this product. (I
apologize if this sounds like infomercial on General Magic's product, certainly didn't
mean that way). In essence, it makes lot of sense in viewing W3 alternatively in a
"non-document" centric manner as well. At this point, i am not sure what is the best
way to do this in W3, certainly W3 is powerful and flexible enough to allow us to
accomplish such a thing. Sounds like there is need for a
multimedia-scripting-and-synchronization language (whatever that means....). Shall
get back to you on this more after careful thinking. 


Vinay Kumar

vinay at eit.com 

CGM

From: ansi at niwot.scd.ucar.EDU (lofton henderson)

Date: Wed, 2 Feb 1994 13:12:49 -0700 

I have recently seen some pieces of email dialog on the subject
of a Universal Network Graphics Language.  I have comments to
offer on a couple of aspects of the issue.

It is interesting that no one has mentioned the format that seems
to be the obvious solution -- Computer Graphics Metafile (CGM).
The mail dialog that I have seen so far proposes PostScript/PDF,
TIFF, NAPLPS, and various other private formats.

CGM:1992, especially with the pending completion of Amendment 2
(Application structuring) has all of the features named, except
for 3D.  A 3D extensions project is being studied now by ISO
graphics standards committees.

It is declarative (as opposed to procedural), and it a highly
efficient device- and application- independent graphics format.
The Version 3 definition of CGM:1992 is roughly as capable as
PostScript level 2 in graphical expressive power.

It is a composite vector/raster format, so it preserves editability
and the ability to manipulate the picture (as opposed to TIFF).
Virtually all commonly encountered 2D graphical primitives can be
translated directly into CGM elements.  Scanned images can be 
embedded as tiled raster elements.

It has two flavors of structuring.  "Segments" are a graphical
efficiency mechanism, for saving and reusing sets of primitives
(which can be instantiated with different attributes, transformations,
etc).  

The Application Structuring of Version 4 metafiles (Amendment 2,
anticipated completion summer 1994) lists among its target
capabilities "network distributed graphical applications", 
interactive electronic manuals, etc.  It includes not only the
ability to divide the metafile into pieces of application (as
opposed to graphical) significance, but also includes picture
and structure directory features.  The pictures can be completely
indexed, "objects" are randomly accessible, and any variety of
Structure Attributes can be defined and attached to the structures.

It is an ISO standard (ISO/IEC 8632), and has been around for 7 years
(it was republished in 1992).  It has been designated as the graphical
content architecture by a number of electronic documentation initiatives:
the ISO Office Document Architecture standard (ODA); the electronic
document programs of US DoD (CALS) and international commercial
aviation (ATA/AIA); it is the graphical basis of the ATA "intelligent
graphics" and intelligent electronic documents program; etc.  It is
also a European standard (EN) and national standard of most of the
main industrialized countries.

There certainly would seem to be some advantage to using ISO standards
where suitable ones exist (I have worked on ISO graphics standards 
committees for a dozen years, principally on CGM).

It is widely implemented (but not always well) -- the CALS Test Network
(CTN) lists several hundred products that claim CGM support.

A testing and certification service for products has just been
established, by the National Institute of Standards and Technology
(NIST, a part of the US Department of Commerce).

It is certainly worth looking into, as it seems an ideal candidate for
your projected application.  I'd like to offer a couple of other remarks
in closing.

Firstly, some of the mail has talked about time, the nature of time,
and synchronization.  For that aspect of the problem, there is an
ISO standard, HyTime, whose purpose is exactly synchronization and
integration.

Secondly, there are numerous standards efforts underway to look at
the whole picture of interactive electronic documents, distributed
multimedia, etc:  MHEG (Multimedia hypermedia experts group),
HyperODA, IMA (Interactive Multimedia association), OMG, SC24/PREMO
(Presentation Environment for Multimedia objects), to name just
a few (in this very crowded field).

Finally, it seems to me that there is some confusion in the mail
between the graphics formats used to support a set of requirements
for distributed interactive network graphics, and the tools that
actually provide the services.  There is obviously some relationship,
but the solutions will be forthcoming more quickly if the separation
is kept clear.  My specialty is formats, so I've limited the bulk of 
my comments to that topic.

Regards,
Lofton Henderson.

Henderson Software Inc.
1919 14th St., Suite 610
Boulder, CO   80302 
USA
ph:  (+1) 303-442-6570
fx:  (+1) 303-442-6572
Internet:  lofton at ncar.ucar.edu;  or, lofton at cgm.com

(As you might guess for the 2nd Internet address, our business is CGM).






Distributed Interactive Simulation

Virtual Reality

Anyone got any leads on this and standards in use? The following was from the IETF
list. 

From: Margaret <MLOPER at ucf1vm.cc.ucf.edu>

Date: Wed, 02 Feb 94 09:00:27 EDT 
The Distributed Interactive Simulation (DIS) standards being developed under IEEE
are for linking simulations at multiple locations to create realistic, complex, virtual
"worlds" for the simulation of interactive activites. Our work over the past 5 years
has focused on connecting military simulations; however, the DIS technology is
applicable to entertainment, medicine, education,... The FAA is even joining our
workshops.

The next workshop is March 14-18 in Orlando. To get more information on this
subject, please contact Caroline LaFave at 407-658-5518 or
clafave at admin.ist.ucf.edu. 
Margaret Loper, PM DIS Standards

Institute for Simulation and Training

3280 Progress Drive

Orlando, FL 32826

407-658-5517 

Labyrinth

From: mpesce at netcom.com (Mark D. Pesce)
Subject: VR and WWW - LABYRINTH Project...
To: timbl at www0.cern.ch
Date: Thu, 17 Mar 1994 10:28:39 -0800 (PST)


Tim -

I was on www.info.cern.ch today and saw a discussion of VR and WWW. Well, it's
already being worked on, here in SF, and I hope that we'll be able to contribute it to
the public domain before Summer is over. In any case, we'll be showing it off at
SIGGRAPH (hopefully) as part of the SIGKIDS exposition, to show how VR can
make WWW sites like the U.S. Library of Congress more navigable to everyone, not

just children.

I've enclosed a short document describing the rationale and goals of the Labyrinth
project. Any comments you care give would be greatly appreciated.

Any help/pointers you can give to people doing similar work would be greatly
appreciated. Thanks for all your great work on WWW! We're glad to be able to add
to it. 
Mark Pesce

Network Zero

San Francisco, California, USA

mpesce at netcom.com 
Tim BL