LANG: Open Inventor

Mark Waks (
Mon, 20 Jun 94 16:23:52 EDT

And on to the next. I've read the documentation that I've found on the
Web about Open Inventor: the "Nodes Quick Reference" and "How to Write an
Open Inventor File Translator". I would *love* to get more information --
does anyone have any pointers to harder info than this? (This appears to
be all that's available on the SGI Home Page.) I'd prefer not to have to
buy the Inventor Mentor if I can avoid it -- I'm a bit poor this month...

Anyway, this is a first impression, based on what I can glean from the
aforementioned docs. Inventor looks *damned* impressive. Its level of
functionality is head-and-shoulders above all the others I've seen --
they've already defined how to deal with problems we haven't even started
to think about yet (eg, animation). The attitude looks right, reasonably
object-oriented and flexible. The file format looks easy to parse, and --
perhaps more important -- easy to subset.

It's not perfect, of course -- we'd still have to add the functions for
fetching objects over the Net. But we might even conceivably be able to
do that without changing the language -- it appears to have a few hooks
for putting arbitrary string commands into the file, which we might be
able to adapt to our needs. Taken on its own, the language looks like a

The issue, of course, is that it's SGI's format. That has a couple of
implications. First of all, we *must* get a *clear* statement from SGI
before we even contemplate using Inventor as our file format. Yes, SGI
makes a big deal about it being an "open" standard. But it's very easy
for a company to say that, while meaning that they intend to supply
tools to anyone who will pay the price. We need an unambiguous statement
that it's okay to (for instance) write non-SGI-related tools for
interpreting this format, or modify the language slightly.

The other implication is that it's generally a poor idea to *almost*
match a standard. Inventor is one of the major players in the 3D-standard
game, and we're likely to find it to our benefit to stick to the standard.
There will be real pressure to make our extensions 100% compatible, which
*might* prove limiting (or might not).

On the other hand, I gather that there's quite a lot of existing visuals
out there in Inventor format already -- making it near-trivial to port
those to VRML would probably increase the speed with which it catches on
by quite a bit.

My feeling is that this is clearly the best format I've seen so far,
*provided* the language lives up to the hints in the online docs and
SGI is willing to be truly open with the standard...

-- Justin
Downloading Geomview even now -- my lord,
that is one *huge* tar file...

Random Quote du Jour:

>From Syr Murphy's laws of SCA combat:
"19. This is SCA. The general manages a McDonalds, and the guy guarding
your flank believes Elvis is still alive. The guy on the other flank
not only believes elvis is still alive, but talks to him at K-Mart.
...Good thing there is no steel on the field, huh?"