Re: my two more 2 cents on VRML (was Scripts vs. APIs)

Linas Vepstas (
Thu, 8 Sep 1994 19:20:57 -0500

Hi Wei,
I suspect the following will reveal my ignorance ...

>Date: Thu, 8 Sep 1994 12:42:04 -0700
>Subject: my two more 2 cents on VRML (was Scripts vs. APIs)
>* Uses SGML, so that it might blend in with HTML better.

I have a copy of the SGML spec on my desk, and it is well-nigh
incomprehensible. Bubble diagrams everywhere, with UI1's and
Msg div's and Doc navig's and Alt title's and Biblio Subdiv's
and Excerpt Source's and Misc Msg Descrip's and Msg Audience's
and Aud Response's and (lang)=NLS ...

And not a single example of what the ASCII syntax is supposed
to be! I find this very scary ...

>* Objects can send and receive messages. Scripts can be attached to
> the object to program the behaviour of the objects...

I would be happy to see a 3D analogue of HTML's href= ... syntax.
Thus, clicking on a 3D object would cause an http request to be sent.
The reply could, for instance, be a change request that would
change, e.g. the location or the color of some 3D object.

I am nervous about trying to define some sort of autonomous agents
that go around sending messages to one another (imagine ... my home
page talking to your home page ... while nobody is watching ...)

>* There is an set of standard messages that objects send&receive.
> This is the "API" part I suppose.

API == Application Programming Interface, which (to me) means a
C-language binding to a set of subroutines ... so I'm not sure
quite what you mean here ...

>* Some kind of objects changes synchronization/propagation mechanism
> such that changes to one object instance on machine A will be
> reflected on machine B,C,D... (ie: move a chess piece on a board,
> and everyone watching the board sees the piece moved).

Hmm. Interesting. This is obviously of general use, and not limited
to 3D. A kind of "cache invalidate" message ...

There is some group that is working on developing a standard way of
caching/mirroring commonly referenced HTML documents, so as to
avoid network overhead & overburdened HTTP servers. Maybe they
have a mechanism already worked out for doing this?

>-Pei Pei Y. Wei