Re: 4vectors

Mark Waks ([email protected])
Thu, 25 May 95 11:22:05 EDT


Pete writes:
>You seem to be lumping together the two different ways to make changes
>in a scene. I would call a scene "dynamic" *only* if some external
>server was making changes to it, and dynamically updating the browser.
>Therefore, a scene with animation coded into it is still "static."

Not quite the definitions I would use (and have been using). Among other
things, this is limiting -- there are a number of other "dynamic" forces
than just the server.

Rather, I'd say that a scene is "static" if its behaviour is identical
each time it is uploaded, if it is completely reproducible regardless
of the outside factors. It is "dynamic" if there *are* outside factors
that act upon and affect it, be they the server, the user, or some sort
of program.

(Indeed, I'll be surprised if server-driven dynamism ever goes anywhere.
It puts the processing requirements at the wrong end, requiring the
server to do the processing for all of its clients. That's a nasty
bottleneck for most applications. Regardless of the exact API chosen,
I expect most dynamic processing to happen on the client in some
fashion, just because clients usually have far more horsepower to
spare.)

>I don't think the animation functions completely solve the dynamic
>update problem, which is essentially a transport issue.

Well, more than just that. But the point is taken.

> However, I
>disagree with your statement that the encoded-in-the-scene behaviors
>should not be part of the spec. I think they belong in the spec even
>more than the dynamic update features.

I'd disagree with "more than", but that's because my model of the
right way to handle dynamic features (a proper programming language, a
la Java or the Geomview language) could subsume all of the capabilities
of such scene-coded behaviours. But yes, it's useful to have such
things in. When you *do* want a simple static behaviour (and they are
often quite useful), the engine model is almost certainly an easier
way to implement it than a full-fledged program. (And that _ramp
function of yours is a very nice general-purpose mechanism. Does
Inventor have anything similar? I don't notice anything quite like
it in a glance at the Mentor...)

-- Justin

Random Quote du Jour:

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a fierce race of mutants with long fingernails, screechy voices and skimpy
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alienation toward the world and each other."