Mark Waks (
Mon, 20 Jun 94 14:38:58 EDT

Okay, next set of comments. I've just dug through the draft spec for
the "File Format for the Interchange of Virtual Worlds", by Roehl and
Bonin. Quick impression: not bad, but not good enough.

The concept underlying VRIF (is this an official name? I think I
picked it up from Jerry) is a good one. It's intended to be a neutral
interchange format for VR info, and on the face of it would make a
nice starting place for us. The syntax is extremely regular and
logical, and should be easy to parse.

The problem is, the format is still *very* first-draft, and there are
some serious bugs. It assumes that file names are DOS-style. It tends
to use integer handles for referring to objects, where names would
often be clearer. (It provides a means of giving names to objects, but
provides no way of using them; this seems silly to me.)

One of the biggest flaws is that it doesn't appear to have any concept
of type hierarchies. It allows you to associate objects hierarchically,
but only in the instances (the "objects"), not in the types (the "shapes").
This would seem to make it a real pain to define complex reusable objects.
(An aside: one problem I'm observing with a lot of these VR languages is
that they don't have a clear distinction between type and instantiation;
blurring the two often results in strange gaps in functionality. I think
one reason I rather like MSDL is that it most clearly delineates what's
a type and what's an instantiation.)

It *does* have a concept of sounds, which none of the other formats I've
read so far has. I'm not sure that their sound mechanism is robust enough
yet, though (it certainly doesn't have any way of triggering sounds
dynamically yet).

And I don't believe it's got much by way of tools yet (although the
introduction makes it sound like they have some draft parsers).

All in all, while I strongly like the concept of having VRML key off
an existing or developing standard, VRIF just doesn't look like it's
far enough along yet -- its bugs are a little severe. I wouldn't mind
working with the VRIF folks and trying to merge our efforts, but it's
not clear to me whether it's worth it if we're running faster than
they are.

So far, MSDL is still my favorite, with OOGL a close second (subject
to change after I play with Geomview a bit)...

-- Justin
On to Inventor...

Random Quote du Jour:

"I ran out of Thorazine and the voices told me to miss the test.
My adolescence got the best of me.
My grandmother died. ("When?") 1974."
-- from "Final Impotence: Reasons Why I Missed the Test"