Re: A full-fledged VRML proposal

Mark Waks (justin@dsd.camb.inmet.com)
Fri, 16 Sep 94 11:04:56 EDT


Dave writes:
>I liked the subset of Inventor you selected in your proposal
>for VRML, but have reservations about how Inventor scene graphs
>are expressed as ASCII text. In particular, I think we should
>be using a structured programming style which is cleaner and easier
>to read and modify. Computer science has come a long way from the
>bad old days of using flow charts for program design. An explicit
>syntax for scene graphs with separator nodes etc. is hard to read
>and understand in just the same way that flow charts were.

You're comparing apples and oranges here. A structured programming
style isn't appropriate, because this is *not* a programming
language that we're talking about. Rather, Inventor is an
object-description language. And it's *quite* well structured
for that purpose -- it's hierarchical in much the same way that
reality is. The only real weakness of the Inventor language is
the way that properties apply to *everything* after them -- on the
other hand, this takes only a little getting used to, and is quite
easy to deal with once you have...

>I will work through the Inventor Mentor and your proposal to try
>and come up with cleaner syntax than can be easily parsed into
>the underlying scene graph.

No. I'm sorry, but this kills the whole idea. The point of using
Inventor in the first place is that it's a language that's already
out there, being used by a whole lot of people. There are changes
that can be made relatively easily, such as limiting ourselves to
a subset of the language. (Although our parsers should try to be
forgiving if elements of Inventor that we don't understand sneak in.)
But the syntax is the heart of the language. Change that, and we've
got an entirely different language, and have just sacrificed the
benefit that would have accrued from using Inventor...

-- Justin
Wearing his Languages Mavin hat...

Random Quote du Jour:

"The gardan party is a scrum of 1,000 people wishing they were indoors and not
standing in the pouring rain (Britain) or sweltering in 90 degrees F (America).
... Houston is always sweltering. It is therefore ideal for garden parties."
-- From "A Guide for the Bewildered", in The Economist