Re: VRML Survey now online

Mark Waks (
Wed, 20 Jul 94 13:22:46 EDT

Paul writes:
>> Matrix Representations
>The issue was not the format, but the generality of the supported
>transformations (all projective transformations vs. just rigid

Just a comment here -- the format is *an* issue. Personally, I want
to see simpler tranformation commands also available (eg, "shift",
"scale", etc), so that someone can write basic transforms without
knowing the relevant math. That wasn't covered in the survey; I
plan on bringing the point up again later...

However, I suspect that having the general matrix representation is
*also* quite useful (and arguably should come first)...

>> Two-tier system: object description files and scene layout files?
>Since we want to be able to inline and embed objects from around the
>Web into a single scene, we obviously don't want to require every
>object file to be a complete scene (with lights, camera position,
>etc). I'm probably misunderstanding the question.

I dunno -- that's how I read it also. I regard it as absolutely
*critical* that we have the ability to define files that just contain
objects; without that, I don't see how we could ever hope to
distribute the object base. I was a little surprised that this was
even a question; I had figured it obvious that we needed to be able
to separate objects from scenes. (Fortunately, most (all?) of the
proposed systems allow that fairly easily...)

>> Engines
>What exactly is an "engine"? Are you asking if the language itself
>should be required to predefine interactive behaviors for specific
>objects like doors? Or are you asking whether the language should be
>capable of supporting references to common scripts?

I think the concept here is taken from Inventor. Inventor systems are
made up entirely of nodes and graphs; one type of node is an "engine",
which allow you to manipulate the fields in related nodes in various
simple ways. Basically they allow you to attach simple dynamic
properties to the graph in a fairly elegant way.

I assume that the question is, should we have something like this
in VRML?

-- Justin

Random Quote du Jour:

"And David did see Bathsheba bathing and did exclaim 'Yum!'"
"And Jesus did say 'I....hurt.'"
-- from the King Chris Edition of the Bible, courtesy tyg