[X3D-Public] [Cad] revising CADInterchange profile

[Don Brutzman]

Also needed:

* ViewpointGroup
** Allows nesting of Viewpoints within models without exploding or overloading the Viewpoint list, which is an essential tool for user navigation.

Tesselation consistency
    Exporters can significantly reduce file size using primitive-geometry nodes (e.g. Cylinder, Disk2D, etc.)
    Tesselation quality is not strictly defined in X3D
    In order to match polygonal tessellation strictly and avoid "cracks" between adjacent geometry, some form of association is needed (similar to the NURBSet node)
    All CAD geometry appears inside a CADPart node, typically one-by-one within child CADFace nodes
    CADPart is a natural node for this functionality.  Node semantics can be improved to include this constraint.

These changes have been collected and will be continue to be improved
on the following wiki page.

	X3D v3.4 CAD Improvements
	http://www.web3d.org/x3d/wiki/index.php/X3D_v3.4_CAD_Improvements

I've named this "v3.4" improvements since that was what we seemed to
think best during the call, as described in the meeting minutes.

Continued consideration and improvement is welcome.  This is the list
that we want to send to browser builders so that they can support CAD.

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman