Re: Non-geometrical things

Eugene Chalfant (chalfant@zappa.jpl.nasa.gov)
Fri, 24 Jun 94 10:53:08 PDT


It seems that, due to the complexity of describing a 3d environment vs. text,
that we should "hierarchicalize" the description, which allows a browser to firs
first load the simplest description (perhaps a vertex list or just a bounding
box), which allows the user to see the object immediately, and then have the
browser auto-load hierarchically to the limit of its capabilities.
So, for a particular scene, the browser first loads a light source, object
blobs or wireframes along with location/orientations, and displays that.
As the user looks around, the browser can at the same time load colors, tex
maps, additional vertices, polys, or volumes. Once the browser has loaded
all the static info for a scene, it can then start with the dynamic aspects:
how does the object react to stimuli, how does it move, what sounds does it
make? These behavioral processes need to be downloaded in a standardized way,
like as a C program perhaps, or some specialty language. But, there'll be
plenty of time for that later.

Does Inventor or any of the other object description protocols have such a
hierarchical structure?

The hierarchical structure solves the problems of multiple platforms,
scalability, simple extension to future capabilities, best use of bandwidth,
and probably some others.^C

-- Gene