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- From: Jean-Marc Vanel <email@example.com>
- To: firstname.lastname@example.org, Patrick Laug <Patrick.Laug@inria.fr>, Amine Hassim <Amine.Hassim@inria.fr>, email@example.com, Frederic ABIVEN <Frederic.ABIVEN@teaser.fr>, Jean Marc VANEL <firstname.lastname@example.org>, "TDWG-SDD@USOBI.ORG" <TDWG-SDD@USOBI.ORG>
- Date: Wed, 01 Mar 2000 08:44:27 +0100
I have followed the debates about VRML/X3D
for weeks, and it's time to speak.
The aim of our project is to make botanical data available on Internet,
including 3D images.
We need a compact, non proprietary, preferably XML, clean definition
for complex 3D geometries.
It seems that a representation both compact and flexible should be based
on mathematics. VRML's cones and cylinders are just special cases
of intersections of volumes defined by equations:
NURBS and Beziers patches are just special cases of surfaces defined
by 3 functions R2 ---> R3
(u,v) ---> (X(u,v),Y(u,v),Z(u,v))
A solution is to use the content part of MathML.
I have reviewed it: it has the desired capabilities, i.e. allows to define
functions and sets, it is XML. Certainly only a subset of MathML is needed:
n-dimentional geometry, n>3 is not relevant. On the other hand, some geometrical
primitives could be added :
- convex hulls,
- recursive constructs like fractals and L-systems,
- transforms, deformations, parametrization, movement
My second point is about modular schemas versus monolythic Schemas.
X3D is a very "good" example of monolythic DTD. NOTHING is taken from the
XML world outside X3D.
It seems that Virtual Reality involves several layers that can be used
and designed independently:
- volumic objects definition (see above)
- colors and textures on volumic objects
- behavior of volumic objects among them (contact, glued or sliding,
rotating, interpenetrable, etc)
- behavior of volumic objects with User Interface
- a scene as composite Design pattern of volumic objects
- light sources
- scenarios (time-dependant aspect )
This need for a compact, non proprietary, preferably XML, clean definition
for complex 3D geometries is common with other important domains:
- Computer Aided Design
- simulation in mechanics, physics, and biology
CAD is a very important field that has currently no XML non-proprietary
language. It seems that the proposed solution could bring an interesting
synergy able to speed up developments, together with a better design. And
also a common subset for CAD and Virtual Reality will bring new possibilities
to exchange data.
A well-designed model and XML syntax for virtual reality could also
be used for cartoons and video games.
<project>Worlwide Botanical Knowledge Base -
making botany available on Internet
(eventually put "wwbota" in subject to route your mail in relevant folder)</a>