WebOOGL demo online

Mon, 1 Aug 94 15:05:18 -0500

The Geometry Center now has a demonstration implementation of
WebOOGL, its WWW-aware extension to the OOGL language, at:


Some interesting points about the system:

We found it helpful to adopt HTML's "link relationships" as
attributes of the WebOOGL hyperlink object. In 3D, the semantics of
a link become much more important. For example, it's desirable to
distinguish REL="Embed" links from default "teleport" links, without
requiring scripting.

The system uses both symbolic references ("handles") as well as URL
caching to provide object standardization and thus avoid excessive
downloads. For example, there are predefined handles for letters and
numbers to provide a standard 3D font (so { : A } gives the letter
A, and so on). The URL caching can also provide standardization in
conjunction with WebOOGL object repositories, such as the one we've
started (so { < http://www.geom.umn.edu/objects/cube.off } provides
a standard cube which will be downloaded only once).

It is worth noting that no new features had to be added to Geomview
itself -- the demonstration relies only on the extensibility of
Geomview, X Mosaic, and the OOGL language. In fact, the system is
currently implemented as a pair of Perl scripts.

Although it would not be difficult to enable downloading of scripts
(in arbitrary scripting languages) as well as WebOOGL, we decided not
to do this because Geomview doesn't yet have a "secure" mode which
disables potentially destructive command verbs.

Paul Burchard <burchard@geom.umn.edu>
``I'm still learning how to count backwards from infinity...''