A few years ago we developed a program to draw polyhedrae,
using Silicon Graphics Inventor format which later became VRML.
Several members of this newsgroup (Armel le Bail, Mike Glazer,
Bob von Dreele and others) further developed the visualisation
of polyhedrae using VRML.
In the original SGI format it was possible to visualise the dynamic
tilting of the octahedrae, or indeed any periodic motion, phase T/N
etc. Unfortunately no-one has yet carried this over into VRML-2,
but if you have a Silicon Graphics machine, you can still visualise the
original dynamic models on http://www.ill.fr/dif/3D_gallery.html
using SGI system software "ivview".
Even if you don't have an SGI machine, I suggest that you would still
be better off using one of the 3D structure drawing programs (see eg
Armel's review: http://fluo.univ-lemans.fr:8001/vrml/intvrml.html
>>does anyone know of physical modelling kits
>>consisting of polyhedra (specifically silicate tetrahedra)
>>with attachable, flexible hinges on the corners that can
>>be used for modelling work? (Useful for looking at how the
>>tetrahedra/polyhedra interlink and can move)
>
>I don't have an answer to your question, but I picked up on the
>bit "looking at how the tetrahedra/polyhedra ... can move". This
>is a non-trivial issue that our research group has been looking
>at theoretically for a few years.
Alan Hewat, ILL Grenoble, FRANCE <hewat@ill.fr> tel (33) 4.76.20.72.13
ftp://ftp.ill.fr/pub/dif fax (33) 4.76.48.39.06 http://www.ill.fr/dif/