Short report from Computer Graphics 91 (UK) 
Author Message
 Short report from Computer Graphics 91 (UK)

Last week I managed to make it down to the CG91 exhibition, staged at
London's Alexandra Palace.  Here are a few impressions/comments.

This event was disappointing considering that it's supposedly the UK's
major graphics show.  There was a "virtual world" area, but even this
was not very well represented.  The two main exhibitors there were
Virtual Presence Ltd, who are the UK Distributors for the Sense8
WorldToolKit, and Division Ltd who are currently receiving media
attention due to their PROvision system (see BYTE Oct 1991, [p.80IS-53
in UK edition]).  It may be worth mentioning Dimension International who
were also exhibiting what they called a VR product.  What this comes
down to is - essentially - a 3D modelling system.  They had a reasonable
frame-rate on their "Virtual Reality Toolkit" running on a 486 PC with
TMS34020-based graphics card, with navigation being provided by a 6-axis
"spaceball" and the image displayed on a desktop monitor.  They referred
to the concept as "Desktop VR", but I can't help thinking that this
smacks of bandwagonism...

Virtual Presence had a Sense8 system using either VPL eyephones or
another headset from the US that looked like a white metal welding
mask perched on top of the wearer's head.  This latter unit was the
one being used for today's demo, but the Logitech tracker being used
to track head movement had died, reducing the effect somewhat.  The
monitor displaying the victim's virtual view showed virtual rooms
with window frames, doors and pictures on the walls that had all been
chosen from the large collection of predefined textured objects
supplied with the WorldToolKit.  Even some tropical fish could be
seen swimming around nonchalantly in virtual space!  The system runs
on a 4 Mb 386 or 486 PC with an Intel i750 graphics board (or two
boards if eyephones are to be used).

On the stand next door, Division had a healthy-sized queue of eager
{*filter*}nauts waiting to try out their PROvision system.  The
demonstration system had a "free" 6-axis joystick with 2 top buttons
to move forward and backward and a trigger button for grasping
virtual objects.  The headset was another VPL unit including
headphones.  I was told that this unit has a field of view of 100
degrees horizontal by 60 degrees vertical.  Compared to some other
systems, the frame rate of the animated display - which could be seen
on the usual monitor - seemed quite slow and jerky.  We were told
that the image rendering subsystem was implementing radiosity, which
could explain the relative slowness of the display, although
something was muttered on the demonstration videotape about using
pre-calculated radiosity values.

The demonstration world available for exploration looked pretty good
on the monitors: a corridor with many doors, each of which opened
onto a room featuring a variety of objects.  One room had a TV and a
Teapot (with shading) while another had a giant chessboard floor
complete with black and white chesspieces that could be picked up and
hurled around (the rate of gravity had been set fairly low, so they
took a while to fall to the ground).

Donning the eyephones and entering the virtual world revealed the
immersed view to be quite different: the heavy use of lenses meant
that the image was marred by concentric rings, although though these
disappeared somehow after a minute or two.  The eyephones were
uncomfortable, with a tendency to slip forward and away from the
eyes, due to most of the weight being concentrated at the front of
the unit.  The goggles also seemed rather warm, causing slightly more
discomfort to the eyes.  Despite the problems I managed to stumble
into the Teapot room and inspect the teapot in the middle of the
floor by kneeling close by.  I then picked it up and walked over to
the TV and inserted the Teapot into the side of the TV.  This
revealed two problems that I presume are common to most VR systems
today.  

Firstly the lack of depth cues meant I was having difficulty
finding the television because I was so close to it and it seemed to
have disappeared.  Secondly, due to the lack of any force-feedback or
"bump-detection" I found myself bumbling around inside the space
occupied by the television wondering where it had gone.  Still
confused I managed to find the door and went back into the corridor -
teapot still in hand - and entered another room after being greatly
baffled by the door due to standing in the doorway intersecting the
closed door!  

My brain gave up at this point and all I could make out
in the new room were the light blue walls, apparently missing the
sticks-and-balls molecule-like creature bouncing up and down on the
floor (this could easily be seen on the monitors, however).  Despite
the visual problems the sound was helpful, with the doors creaking
opening when necessary (sometimes).  The teapot also made a sort of
quacking noise that become louder as it was approached (!).

CG91 also featured a half day tutorial on VR by Charles Grimsdale,
Division's Managing Director, as well as a 1.5 day conference chaired by
Iann Barron, Divsion's Chairman.  Among those billed as being present
was Scott Fisher, who I presume we all know (his new company
Telepresence Research is using Division's PROvision system, according
to Division's press release).  I'm sure the other readers of this group
would be interested in hearing the comments of any netters who managed
to make it to this conference.

---------------------------------------------------------------------------
Contact Addresses:

DIVISION Ltd            Virtual Presence           Dimension International
Quarry Rd               25 Corsham St              Zephyr One
Chipping Sodbury        LONDON   N1 6DR            Calleva Park
BRISTOL  BS17 6AX                                  ALDERMASTON   RG7 4QZ
UK                      UK                         Berks, UK

Tel. +44 454 324527     Tel. +44 71 253 9699       Tel. +44 734 810077
Fax. +44 454 323059     Fax. +44 71 490 8968       Fax. +44 734 816940
---------------------------------------------------------------------------

Cheers,

Chris



Fri, 29 Apr 1994 05:51:29 GMT
 Short report from Computer Graphics 91 (UK)

Quote:
>Donning the eyephones and entering the virtual world revealed the
>immersed view to be quite different: the heavy use of lenses meant
>that the image was marred by concentric rings, although though these
>disappeared somehow after a minute or two.  The eyephones were
>uncomfortable, with a tendency to slip forward and away from the
>eyes, due to most of the weight being concentrated at the front of
>the unit.  The goggles also seemed rather warm, causing slightly more
>discomfort to the eyes.  

Sounds a lot like an unmodified LEEP {*filter*}face unit.  The optics
are plastic lenses, and give lots of internal reflections.  These
disappear because they are stationary to your head, and are low
resolution, so your brain edits them out fairly quickly.

The {*filter*}face mount never was much good.  I think most buyers
replace it with their own mount as soon as they try it out.

Quote:
>Despite the problems I managed to stumble
>into the Teapot room and inspect the teapot in the middle of the
>floor by kneeling close by.  I then picked it up and walked over to
>the TV and inserted the Teapot into the side of the TV.  This
>revealed two problems that I presume are common to most VR systems
>today.  

This illustrates both the problem with and the need for high-level
representational languages for VR.  Present VR languages (what there
are) aren't really set up to handle every possible object manipulation
possible, you must list them.  Sounds like someone either slipped up
in specifying one of the object's parameters, or the whole thing was
put together without a HLL at all.

What we need is libraries of objects (and a standard, first!) that have
realistic parameters automatically assigned: i.e. noninterpenetrability,
a weight (future, of course), center of gravity, sound when tapped, etc.
No one can throw together a VR world if they have to do everything in
C!  That's the VR system writer's job.

Quote:
>Firstly the lack of depth cues meant I was having difficulty
>finding the television because I was so close to it and it seemed to
>have disappeared.  Secondly, due to the lack of any force-feedback or
>"bump-detection" I found myself bumbling around inside the space
>occupied by the television wondering where it had gone.  Still
>confused I managed to find the door and went back into the corridor -
>teapot still in hand - and entered another room after being greatly
>baffled by the door due to standing in the doorway intersecting the
>closed door!  

>My brain gave up at this point and all I could make out
>in the new room were the light blue walls, apparently missing the
>sticks-and-balls molecule-like creature bouncing up and down on the
>floor (this could easily be seen on the monitors, however).  Despite
>the visual problems the sound was helpful, with the doors creaking
>opening when necessary (sometimes).  The teapot also made a sort of
>quacking noise that become louder as it was approached (!).

Sounds like a AWFULLY bad "trip"!  Wonder how much of this it would take
to drive someone completey nuts?  Seriously,  I think that the low
resolution (lack of detail) in today's VR systems make it easy for
the brain to ignore things.  This is similar to the "Ganzfeld" effect
where a lack of detail in the visual field (induced by half-pingpong
balls over the eyes) causes a subject to lose all vision after a
few minutes.  Lack of intersection feedback and force feedback
don't help make you believe, either.

Here's to a better, and let's hope, *sharper*, future.

--------------------------------------------------------------------------
| My life is Hardware,                    |                              |
| my destiny is Software,                 |         Dave Stampe          |
| my CPU is Wetware...                    |                              |

__________________________________________________________________________



Sun, 01 May 1994 13:43:05 GMT
 
 [ 2 post ] 

 Relevant Pages 

1. CFP: Short articles for SIGGRAPH Computer Graphics

2. Eurographics UK 91 conference

3. Report on Cyberspace Conference 2, Santa Cruz, CA, Apr 91

4. Kahaner Report on Japanese Artificial Reality Conference, July 91

5. Virtual Reality '91 -- brief report

6. COMPUGRAPHICS 91: Computational Graphic Conference in Lisbon

7. ONLINE: Short report on Memory in VR and Augmented VR

8. JAPAN: A short report on Japanese VR applications (In English)

9. JAPAN: A short report on Japanese VR applications

10. CONF REPORT: Kahaner Report: Computer Graphics Intl. '92, 22-26

11. JOB: Computer Science post at Sheffiled University, UK

12. INDUSTRY: Kahaner Report: Sony Computer Science Lab


 
Powered by phpBB® Forum Software