Project Jigsaw:
The Problems of Accuracy & Detailing in VRML
A VRML presentation models the real world by breaking it
down into a series of lines in space. The more complicated
the objects modelled, the more storage they need, and the
more memory is required to display them;
Simple objects - such as a cardboard box - display quickly
and easily; but complicated shapes - such as a complicated cornice,
or the Euffel Tower - will take so much memory that most
computers will be unable to display them;
Whilst we can envisage a time when displaying and
manipulating such models will be trivial, this is not the case
at the moment. The strategy we have adopted is to model
Borobudur in as sophisticated a manner as possible, using
AutoCad, and hope that, sometime in the future, its full
glory can be handled in VRML;
For the time being, however, compromises have to be made,
and these have involved: (1) the simplification of profiles;
(2) the copying of one model onto many where possible (e.g.
Buddha niches; the 72 stupas on the circular terrace); and
most noticeably (3) the disaggregation of the stupa into
constituant parts so that each may easily be loaded into
a VRML browser: because of size problems, each gallery
has been quartered, and each quarter is again divided into
two section comprising (a) the main wall; and (b) the balustrade
wall - that is, 32 separate VRML presentations for the four
galleries, plus another four for the Hidden Basement;
In our presentations, the VRML vectors make polygons, and
each poygon is "clothed" with a photographic image, in an
attempt to give the user the "photorealism" of standard
photographs together with the manipulability of VRML vectors.
Of course, the dimensions of the photographs used impact
heavily on the flexibility of the model; so once again we
have adopted a strategy which will be robust enough for the
future. That is, whilst our photographs of Borobudur are 1.6
megapixels each (about A3), we are currently using a cut-down
series of images for testing purposes. We should be able to
present the iweb-based user with a choice of large or
small image-suites - always depending on network speed,
of course;
On a fast machine with a good graphics card (Pentium
Pro 400 with 128Mb RAM and a Diamond FFireGL 1000Pro
with 8Mb RAM) the manipulation is smooth and easy. With
a "normal" machine (Pentium 133 with 64Mb RAM and
a common-or-garden video card) the presentation will
be slow and jerky;
The presentation will also be offered on CDROM (very
probably on at least three CDROMs), in which case the user
should be able to choose large, medium or small image-suites.
As technology gets faster, so our presentations should look
even better.