carnival by xiaopangnv




"Carnival" or "Farewell to Meat" was an event that NVRCAD set up to promote the use Collaborative
Virtual Environments (CVE's) to allow artists and designers to explore ideas of virtual body and event. This
document describes the technical challenges and organisational tasks involved should you wish to try
something similar.

More details can be found at

Note: Its is worth noting that if 3D on the Macintosh were better supported we would have used a
Macintosh based system as Art and Design Schools still favor the AppleMac.


1.    Abstract
2.    Contents
3.    Keywords
4.    Introduction
5.    What is a Collaborative Virtual Environment
6.    A review CVE software
7.    Software for avatar construction and tutorials
8.    Getting people to participate
9.    Organising the event
10.   Keeping in contact
11.   Controlling the event
12.   Conclusion
13.   Appendices-Mailshot
14.   References

"Organising a complex virtual event uses the same amount of time as organising a complex real


Collaborative Virtual Environment, CVE, Virtual Reality Modeling Language, VRML, Avatar, Carnival,
Artist, Theatre, Blaxxun, Higher Education, HE, Internet, Web Browser, Web Server.


The idea of Carnival was for students and lecturers in UK HE's to design and create imaginative costumes
or floats using 3D software and to 'wear' these to a Carnival in a place called CyberTown. The Carnival
event took place on the 7th of December 1999 in Blaxxun's CyberTown, starting at 5.00pm GMT (12.00pm
CyberTown Time) and carried on for two hours.

The Carnival itself consisted of a procession of avatars through various virtual worlds. We met in the
CyberTown Plaza a gave people time to familiarise themselves with the environment, we then proceeded to
vist three world in the CyberTown suburbs. First we went to TeenZ town, a recognisable and familiar street
setting, we then proceeded to Stonehenge, from there we went to Rickilees Parking Garage finally returning
to the Plaza just under two hours later.

CyberTown is a Virtual Community that runs with the Blaxxun Multi-user world server and Contact
VRML browser pair.
The nature of the event means that there are several elements to its organisation:

1.   Deciding on CVE software and Modeling software
2.   Getting people to come
3.   Helping people build things for the event
4.   Building or choosing an environment in which the Carnival can happen
5.   Timing and arranging the procession
6.   Mediating and policing the procession

What is a Collaborative Virtual Environment?

For the purpose of this document we are going to describe a Collaborative Virtual Environment or CVE is a
simulation of 3D space that is shared across a network of computers. The CVE consists of some interactive
representation of 3D space and some method of passing events between those sharing the representation.

NVRCAD chose to use a Virtual Reality Modeling Language (VRML) based CVE. All the CVE's that
NVRCAD looked at using for the Carnival event were built around the Virtual Reality Modeling Language
VRML specification and follow a simple client and server model. In these systems, although the impression
is given the all users share the same model, each of these representations separate all that is shared are
indicators as to changed of state.

While it is not necessary to have a detailed technical knowledge in order to work with VRML CVE's, it is
useful to understand some of the general aspects of the CVE. When a user first enters a VRML CVE they
are registered as being present and then they are served the representation of 3D space this is interpreted by
the VRML browser. The 3D representation is in general a polygonal geometry rendered in real time with
textures but with no shadows or reflection at what can be quite high frame speeds. Interaction is essentially
triggered animated events of one form or another. An triggered event is then propagated throughout the
representations of those sharing a world.

The server also displays a representation of you in each of the other clients sharing the environment with
you. The representation is referred to as an avatar, its position is tracked and relayed to all clients it also has
an associated set of gestures. Your avatar is a piece of geometry, which can to all intents and purposes be

The Carnival event was about building the Geometry referred to as avatars.

A review CVE software

The CVE divides into two parts, the server and the client. All four sets of CVE software we looked at had
clients and servers that where easy to use for one reason or another. The charts below outline some of the
basic differences between the various bits of software. We have discussed the clients and servers separately
though they can only be used as pairs (mostly).

Review of Servers

You will use the server, you know how easy you need the server to be to use. In the end for Carnival we did
not administer the server and this effected out decision on what software to use.






                                                   Set up




 Blaxxun                       No       NT         easy     easy/h   very            good         yes        No
 DeepMatrix         Java         Yes?     All?         easy/h           easy                                  ok     yes   Yes
 Community          Java         No       NT/9x        easy             easy       very                       bad    ?     No
 Vnet               Java         Yes      All?         easy/h           easy                    Free          good   no    Yes

Review of Clients




                                                                          Set up


 Blaxxun            Appli        Free     NT/9x        Easy             Easy       very         easy
 DeepMatrix         Java         Free     All?         Non              Non        Very         easy
                    applet                                                         unstab
 Community          Appli        Free                  Easy             Easy       very         easy
 Vnet               Java         Free                  Non              Non        stable       easy

Notes: All? Refers to the platforms supported by Java.

We discounted Sony's Community Place browser and client pair early on. Although the applications had
been used by the BBC (because it supports sound?) and BT, we found technical support was difficult to
come by and the extensions to VRML were not well described. Blaxxun was the only CVE where the there
was a good amount of support for construction.

On paper for the technologically literate educational user Vnet is perhaps the most attractive prospect,
simply because it is Open Source and therefore can be used and adapted at no cost. In addition Both Vnet
and DeepMatrix have the distinct advantage of having very very light Java Applet Clients that will run with
virtually any platform. Having said this it has been the experience of NVRCAD that software stability is a
major factor in CVE work, people very quickly leave if they have to fight the software. In general the java
clients and servers tended to fall over with excessive communication. DeepMatrix has proved to
particularly unstable when running with Internet Explorer which we assumed would be popular software.

For the Carnival event we considered that it was an advantage to have to only support one piece of
software. So although Blaxxun narrowed our user group to PC users our task was made easier. In addition
Blaxxun had proved itself to be extremely stable and it has a strong user community. The Blaxxun user
community is not like the Vnet community where the focus is on developing software the Blaxxun
community is more actively social.

So to recap the reasons that we chose Blaxxun were:

1)   Blaxxun narrows the range of support needed
2)   Blaxxun have a very big user community which provided a context for the event
3)   Blaxxun has very good documentation and the extensions to VRML are well described
4)   Blaxxun is very stable

However having made these points Blaxxun is an expensive piece of software and therefore if ColonyCity
had not offered to host and administer the Carnival event for us we would have chosen to use Vnet which
although less stable is an good piece of software.
Software for avatar construction and tutorials

As well as deciding on the CVE software for Carnival we also decided to choose a single piece of software
to support for the development avatars. Because we had already chosen to use Blaxxun as the client and
server we opted for Windows modeling tool for consistency and availability.

Our requirements/considerations were:

1.   Demo or Free version must be available for the duration of the project as very few people could afford
     to buy software for the event.
2.   The software must generate VRML with support for scripting (ideally with support for VRML
     extension used by multi-user systems).
3.   Not overly complex to learn or use.

In a real Carnival the construction of costumes and floats is a sophisticated affair whose organisation is not
part of the main event but are built by competitive groups or organisations. Although we would have liked
to promote this form of collaborative working for our virtual Carnival it was not possible, as 3D modeling
tools do not tend to favor collaborative construction.

Note: One criteria of multi-user worlds is that the VRML geometry be compact many established tools
generated overly complex if very accurate geometry for them to be viable tools.

For the purpose of this review we considered VRML modeling tools divide into Geometry modeling tools
such as 3DSMAX and Rhino with VRML exporters, specific VRML modeling tools such as CosmoWorlds
and Platinum VR Creator and extended VRML modeling tools such as AvatarMaker which can deal with
Avatar making.

There is an enormous amount of software on the market that will create VRML geometry such as the
established and popular 3DSMax, Lightwave or FormZ. We dismissed such tools early on primarilty
because of cost but also because they tended to generate overly complex, if very accurate, geometry for use
in multi-user worlds. Of the geometry modeling tools that exported to VRML we recommended the less
known Rihno3D. Rhino3D satisfied our criteria by being available as a demo version, being very easy to
use with good help files and by allowing the user control over the complexity of their geometry.

Without the benefit of the VRML specification extension to support multi-user operation many of the well
established VRML modeling tools were of no more use than the general tools. The only advantages of tools
such as CosmoWorlds and Platinum VR Creator were that they created very good VRML and allowed the
user to create VRML animations that could be adapted to multi-user function by manipulation in a text
editor. The interfaces in general were less complex.

At the end of the day we found that we needed a tool that would automate some at least some of the process
of creating an animated avatar, not so much the form as the extensions to allow animation etc. Only two
pieces of software (at the time) had good support for the Blaxxun VRML extensions, one was the
AvatarMaker (now owned by Blaxxun) and Spazz3D. We chose to use Spazz3D predominantly because
Blaxxuns AvatarMaker only supported humanoid avatars but also because it seemed to limit the chance for

In the end we chose Spazz3D because it:
1. It was a small and stable piece of software
2. It supported the multi-user extensions to the VRML specification and had specific avatar building
3. It had good help files
4. We got a demo version for the length of the project
Getting people to participate

You have 3 problems:

1) Who do you want to participate?
2) What method and language do you use to communicate with them?
3) How do you hold their attention?

The firsts two points intersect. For Carnival we narrowed the field of participants by only sending out
communications though email thereby insuring a level of technical ability within the audience. Obvious but
it works! Our experience with NVRCAD has been that as much as you may want to give everyone a fair
crack of the whip it is simply not possible or realistic to try to support all levels of computer literacy.

Following on from this point we further narrowed the field with the choice of language and also the subject
matter! Colin Beardon focused the event around theatre by quoting Perocchi and giving the event a theme
rather than laying out a more object oriented brief that would have appealed to the object designers!

Holding the attention of possible participants is perhaps the most difficult. NVRCAD has found that while
for academics a few months is necessary to free up some time in their diaries. For most students a couple of
weeks is all that is needed. Seeing as most such events are extra caricular studenst are going to work on a
short turn around time anyway.

NVRCAD has found that a single mailshot is often enough to scare up a whole range of interest in an event.
With the Carnival event a mailshot was sent on the ??. They event was then posponed for a couple of weeks
and therifore this meant additional mailshots had to be sent.

The time of year of the event you intend to run can have a great deal of effect on its success. For us as our
events would be a low priority on peoples calendar but actually might be something that people want to
attend, we found that it was worth watching upcoming events to see if their was any conflicts. So pretty
obviously we tried to avoid timetable clashes and to aim for a time when people would have finished of
work or not be rushing.

Organising the event

Getting people to organise themselves in a CVE is tricky even when the attendees are familiar with the
software and the protocols and methods of communication. For this reason we did not provide an explicit
itinerary. Because of the openness of the event we were also unable to judge the number of attendees in
advance, although well over 40 people expressed interest in attending there is no way to ensure attendance
at such an event when people are physically remote.

CyberTown/ColonyCity always has a floating population of around 100. We hoped that some of these
people would come along and swell the numbers.
It was hoped that the choice of environments would influence the way in which the event would progress.
For example the hope was that in TeenZ world people would naturally process up and down the main street
and in the Stonhenge world the hope was that people would circumnavigate the stone circle. By then
moving as a group form world to world we hoped that people would develop into a coherent carnival

This did not actually happen. While the event was a great success in that many people attended and enjoyed
themselves the lack of focal point a clear route lead to people simply milling about without a clear task to
perform lead to individual interaction rather than a group task being performed. What did work well was
the movement from world to world, people found that this gave them a sense of being part of something
and despite the relative inexperience of some of the participants the group held together across the virtual

In the end although the event was a success in that people came and enjoyed themselves it did not really
function as a Carnival.

Keeping in contact

The event was organised predominantly by email. Only a few phone calls where fielded and those only in
circumstances where confidence needed boosting or encouragement was sort.

Timetable and itineraries were sent by email these were backed up with a web site that people could return
to for continual updates.

Controlling the event

NVRCAD's has to put its hands up here and say that one aspect of the event that we only considered at the
last minute was security and helpers. We were fortunate in that Cybertown was able to provide 3
individuals who acted as guides/helpers on the day. From my conversations with Blaxxun I gathered these
people were chosen for there knowledge of the software and the there ability to communicate well within
the environment.


In general technically the event was a success a couple of points worth mentioning are:

1.   The files sizes of participants avatars still remained large despite warnings
2.   People who built their avatars in software other than Spazz3D found it very difficult to get the scale of
     there avatars right
3.   Signs and directions were needed for the event during the event
4.   StoneHenge world had audio we did not realise this at the outset of the event, this meant that it took a
     long time for participants to gather in this world


This mailshot was first sent out at the beginning of the summer of 99 three months prior to the event. The
mailshot was then repeated about a month later and then various mails were poste with increasing frequncy
up until the actual date of the event.

Farewell to Meat

You are invited to participate in a Virtual Carnival to be held later this year (Tuesday 30th November
1999). It will mainly involve you (or your students) designing and creating imaginative costumes or a float
using 3D software. The main theme of the Carnival will be "the hidden".
According to Perocchi, "carne, vale" (farewell to meat) is the origin of the word 'Carnival' and it is an
appropriate title for a festival in cyberspace. In losing our physicality, that which is hidden comes to the
fore - we are represented by a mask which reveals an inner truth.

To participate in this event:

(a) register your interest now (email and you will be kept up to date with
information as it becomes available;

(b) if you don't already know how to build an avatar, don't worry - you can attend one of the workshops
held in Coventry, Exeter and Middlesbrough in September and October;

(c) design and build your own avatar (in VRML);

(d) participate on the 30th November and have fun!

Virtual Carnival

The Virtual Carnival is aimed mainly at those involved with Art, Design or the Performing Arts at
University-level. We would particularly like to see groups of students collaborating to design costumes and

The Carnival itself will consist of a procession of avatars through various virtual worlds. The organisational
and technical details will be made available over the next few months.

(The Virtual Carnival is an event organised by the JTAP-funded NVRCAD project
involving the Universities of Coventry, Plymouth and Teesside.)


NVRCAD Coventry


VRML Specification

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