Re: VRML usage

Jon Russell ([email protected])
Tue, 18 Apr 95 23:52:55 BST


[snip ...]

>Is VRML defined to be Client/Server, Peer-to-Peer, or Single System?

IMHO I would say client / server .. even in your stand alone CD ROM example
the CD ROM could still be classed as a server ..

>Another conceptual trauma, even more basic: Are VRML spaces static, or
>dynamic? Obviously there is some dynamism in the use of a link, but does
>that mean that each link simply takes you to another static space? I
>think the answer is "No".

Agreed ..

>This brings us to the question of how interaction is defined (is it part
>of the VRML language?). The reaction some folks had recently to simple
>"rotating" objects leads me to think that such things are not intended to
>be part of VRML.

Why ... v1.0 handles static worlds but v4.0 .. ? we've started now .. why
not extend VRML instead of going off with something different .

>Do we need to limit VRML to the simple process of "marking up" a static
>scene?

Is markup _the_ important feature or just one of many ?

> Should we then define another language for interaction and motion
>("what to do when the user does something"), to add the dynamism of an
>interactive environment?

It depend what you mean by, dynamic, interactive, and motion .. I would say
interactive means to be able to pick up objects, press buttons, move around.
Motion means independent movement that objects possess whether you interact
with them or not (like spinning objects) and Dynamic means events that occur
from external stimuli (perhaps an mpeg stream being played on the screen of
a TV in your world, or another user walking around).

Motion and interaction can be modelled with in VRML as parameters of the
objects : splines and time parameters can be attached to objects to model
motion, and interaction could be defined by bounding boxes, splines etc.

Its' dynamic objects that cause a problem .. you need to be in touch with
the 'server' to update the client view

>This leads me to my last question: Since the dynamic part of VRML is at
>the client, don't we now need yet another language and transport system
>for the servers to run which distributes the changes to the space that
>one user makes, to all the other users who are in that same (multi-user
>interactive) space? Do we need a VR Interaction Protocol (VRIP)?

I would agree that a dynamic transport or protocol is needed ... the dynamic
objects are still VRML objects though except they change with time from an
external source .. the protocol or transport system needs to be able to
update the client with new objects .. this opens a bit of a can of worms :-o

But hey .. it's all possible ... I want to be able to 'jack in' to my VRML
deck and meet the 'matrix'

:-)

Jon.

___________________________________________________
Jon Russell. ( [email protected] )
Microcosm Support & Development,
Department of Electronics and Computer Science,
Southampton University, Southampton.
SO17 1BJ England. Tel : +44 (0)1703 594490
http://bedrock.ecs.soton.ac.uk/Jon/