RE: VRML output

Hi Don,

I looked into automated export of VisAD displays a bit ago.  The
quickest way that I found used the package CyberVRML97
(http://www.cybergarage.org/vrml/cv97/cv97java/index.html).  Export was
easy as all one had to do was created a VRML tree using the VisAD root
branch group from a DisplayRendererJ3D instance and then write it out
using the cv97 API.

When using cv97 with VisAD (as implemented at that time) the issues
were:

1)  Each node in the scene graph had to have CAPABILITY_ALLOW_READ set.
The required changes were implemented in VisAD at one time, but had to
be reverted for compatibility with older Java3D releases where the
required capabilities didn't exist.

2) The polygon winding orders in the VisAD marching cubes implementation
are inconsistent as the polygon normals of the triangle strips appear to
alternate pointing towards increasing and decreasing values of the 3d
scalar grid.  The VRML renderer we used (Cortona) culled polygons based
on the winding order and the surfaces would display with alternate
polygons culled.  VisAD turns off culling so this artifact isn't visible
until export.

We ended up implementing our own export implementation.  If you have
specific questions I should be able to help you...

Tom Kunicki - Senior Software Engineer
Imago Scientific Instruments Corporation
6300 Enterprise Lane
Madison, WI  53719
Voice: 608.274.6880 x203
Fax:  608.442.0622
mailto:tkunicki@xxxxxxxxx 


> Subject: VRML output
> 
> I looked through the archives and found a couple of people 
> who were investigating outputing the Java3D scene graphs as 
> VRML.  Has anyone done this and if so, are they willing to 
> share the code?
> 
> Don

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