Re: LANG: Text in VRML

Andrew C. Esh (andrewes@cnt.com)
Thu, 23 Mar 1995 09:03:41 -0600 (CST)


On Wed, 22 Mar 1995, Linas Vepstas wrote:

>
> Hi,
>
> Whoops! I am trying hard not to flame in the note below ...

Thanks for that.

[big snip]

> I percieved the original note as OpenGL-bashing. I was attempting to
> defend OpenGL, describe why its slower than doom, and to characterize
> what the traditional OpenGL marketplace is like, and what it's customers
> look for. I did not mean to put down DOOM. DOOM is excellent.

I came in in the middle of the thread, and gave it a good topspin lob
back over the net, so the outcome is probably very different from where
the discussion started.

> > poster was referring to Doom to make a point about differences in
> > performance, not exact comparisons. Doom is obviously a toy. His point is
> > that even for a toy, it comes close, and it is a very successful product.
> > Maybe we should think about all those PCs out there that DON'T have extra
>
> Yes. Absolutely.
>
> > special hardware for all this intricate rendering. The average consumer
> > isn't going to want to buy a hulking SGI box just to do virtual
> > walkthroughs of the local shopping mall.
>
> Agreed.

OK. We're on the same track then. I thought the point was that Doom is to
be blown off since it's a toy, as are PCs, and that the only way we should
be thinking about doing VR is with extremely complex software systems
running on (Advertisement!) SGI(tm) hardware. (Call now for pricing and
availability!)

> > > The point is that no serious CAD/CAM vendor would even think of using DOOM
> > > for thier engineering drawings -- its too broke, and too feature-limitied
> > > in too many ways. OpenGL was/is designed to be a very general-purpose,
> > > do-it-all, easy-to-use, h/w-acclerated 3D API. DOOM was designed to be
> > > a cut-corners, never-mind-the-hacks, who-cares-if-looks-wiggy-if-its-fast
> > > game application. It's kind of a mistake to point at DOOM and say, "do
> > > that", and "ohh, do that in a general-purpose way".
> >
> > CAD/CAM? So 3D is reserved only for high minded Visual Engineers doing
> > animated 3D renderings of jet engines and the Space Shuttle?
>
> Never said that. Don't put words in my mouth.

I'm not. You said CAD/CAM, in a context which I took to mean "We can't
use Doom-style software systems because no serious CAD/CAM vendor would
use it." I thought the subject was VR, in general, not specifically what
was going to be of use to a CAD/CAM engineer, and nothing else.

> > Think! Don't throw wet blankets.
>
> I thought, and now I'll throw a real wet blanket:
>
> Is it obvious to everyone on this list that the current vrml, as spec'ed,
> can be made to run fast on a pentium/power-pc class machine?
>
> It's NOT obvious to me. Clearly, VRML, in the form of Iris Inventor,
> runs fine on SGI boxes (and I've seen betas on other platforms). But
> in all cases, (SGI & betas) Inventor is built on OpenGL, which had
> just been flamed for poor performance. So ... what are we saying, again?

I'm saying that if we have a problem, let's fix it. Doom is an example of
a crude but successful system which does run on the PC. I look to that as
motivation to find a solution so that we can all run VR applications, not
just the folks who can afford expensive SGI hardware.

I'm not afraid the market will get reserved and sat upon by SGI. I'm
afraid SGI will make the mistake of centering on it's own systems, and
thereby exclude itself from what is to come. Notice I have been referring
to VR, not VRML. If VRML gets sequestered (a little O.J. lingo here)
among the high priced machines, then something else will become the
standard, as defined down here in the broad market. The home/desktop
system (not necessarily the PC or Mac) is where the money is. Any fool
can do great VR on a Cray.

> Is someone implying that vrml is being ported to a doom-like code base
> for performance? If so, Great! Yes! Do It! Lets discuss what we like/hate
> about the current VRML w.r.t. some non-OpenGL rendering engine! Lets fix
> the vrml spec so that it runs fast, lean, mean on one of these other API's!

The beauty of any software system is that it is limited enough so it runs
well, and thereby can run well anywhere. It may be that the full blown
VRML spec is too complex for any software system that has to run on PC
level hardware. We may need a VRML-lite, composed of Doom-like
constructs, in order to shoehorn it into a PC.

> To the best of my knowledge, no one anywhere has yet indicated, implied,
> insinuated, announced, anything about a/an/some/any implementation of
> VRML that DIDN'T run on top of OpenGL. So if you don't like the
> performance of OpenGL, just wait till you see VRML. So, lesse, where did
> that wet blanket go?

Sounds like OpenGL is going to be a millstone around the neck of VRML.
Watch out. This could be a problem.

> > It's about time 3D came out of the lab. Doom is that first big step. Give
> > it credit for sparking the minds of all those little game crazy
> > teenagers, some of whom will some day join our ranks as top notch
> > computer scientists and engineers, building what THEY envision.
>
> Jeez, I did NOT put down DOOM !

Here is what you said:

"The point is that no serious CAD/CAM vendor would even think of using
DOOM for thier engineering drawings -- its too broke, and too
feature-limitied".

The term "too broke", to me, is a put down, if you mean "broken". If you
mean broke as in "out of money", then yes, Doom has reached its limits.
It's "exhausted", as a technology. Doom is the Apple II of the VR effort:
A bunch of kids in a garage, who make a big breakthrough and become rich
by founding an industry. Let's try to avoid having VRML become an Osborne
Computer.

What's the next stepping stone in the journey to bring VR to the masses?
Let's move on.

---
Andrew C. Esh                 mailto:andrew_esh@cnt.com
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