> Glen Wheless wrote:
>
> >the suggestion of a fourth axis for temporally varying data
> >is a good one.
>
> It actually struck me as completely unworkable.
Yes, I agree. This would be using a simple mathematical scheme to try to
represent a whole different problem.
> What's needed is a language for *describing* movements, rather than
> explicitly drawing them. To explicitly draw each object at a point in
> time would be a step backwards from what VRML represents. It seems to
> me that VRML is about describing rather than drawing. So we need a
> behavior description language.
Yes, and it does not need to be (and should not be) part of the VRML spec.
VRML (IMHO) is intended to be a method for representing static spaces.
Another language can be used to represent changes to those spaces.
Certainly you could load a .wrl file, make changes and save it, but that
is not what I mean by static. A dynamic space would be one which changes
due to external influences, like server updates. A movement file
containing statements written in the same language, along with a .wrl file
which represents a starting point, would be enough to run a 3D
non-interactive movie. Dynamic Data Exchange could also be used to build
the server setup.
This brings up a question: Is there any persistent, general way to refer
to an object in a .wrl space after we are through rendering the space? In
other words, after the browser loads the space, it has internal references
to each of the objects. If you change your point of view (or move
something) the browser (editor) uses the internal reference to change the
location of the affected objects, and renders the new view. I assume it is
not referring to the objects by name. My question then, restated, is: Can
an external server say "Move 'tea-party.wrl/teacup-03' to these
coordinates ..." to my browser?
I realize that there is no such thing as an external server at this
point, but if there were, it would have to refer to the contained objects
by some sort of system which translates into whatever the browser will
understand internally. The reference would have to be exact, and robust
enough to represent any object. At the same time, it could no make any
assumptions about the internal workings of any particular browser.
We need named objects. These are the hooks that a movement language would
have to use to 'enact' a .wrl file.
---
Andrew C. Esh mailto:[email protected]
Computer Network Technology [email protected] (finger for PGP key)
6500 Wedgwood Road 612.550.8000 (main)
Maple Grove MN 55311 612.550.8229 (direct)
<A HREF="http://www.mtn.org/~andrewes">ACE Home Page</A>