[X3D-Public] CAD conference call Tuesday; revising CADInterchange profile

Don Brutzman brutzman at nps.edu
Mon Aug 13 21:49:41 PDT 2012

Since it does not look like there is a Declarative 3D call Tuesday,
Hyo and I are hoping to have a CAD group call 8-9 pacific at the
regular time on the regular Web3D phone line.  Dick can attend too.
Vince and Marc, can you join us?

1.  First topic will be to briefly review a number of discussion points
from SIGGRAPH.  All issues are showing forward progress.  I can send a
scan of meeting notes to teleconference participants, we will get the
details online later.  No doubt these will deserve deeper treatment
on future calls.

2.  Second topic will be to review recent changes to X3D DTD and Schema:

14 August 2012, brutzman, Hyokwang Lee
- CAD nodes not allowed to include Switch (since events not provided by CADInterchange profile)
    or StaticGroup (since reaarrangement/removal of children nodes can break CAD product structure).
    Neither of these nodes are listed in CADInterchange profile.

11 August 2012, Hyokwang Lee, brutzman
- CADAssembly is not allowed to include CADFace as an immediate child since that does not match
    CAD product structure as defined in X3D specification clause 32.4.1

10 August 2012, Hyokwang Lee, brutzman
- CADAssembly:  allow grouping nodes that make sense for CAD, adding Anchor and Inline to match allowed DTD children

3. Third topic: there are a number of issues with the current
CADInterchange profile:  some valuable/essential nodes are missing,
and some questionable nodes are included.


As discussed in recent CAD working group meetings, we are hoping to
build the list of what nodes/components each browser should implement
well to support the forthcoming conversion of many CAD models into X3D.

- Anchor, Inline
- FillProperties
- OrthoViewpoint
- NURBS component
- Geometry2D component

Not needed (or at least very questionable):
- Shader nodes (not portable)
- Multitexture nodes (is there a common use case?)

Other nodes?

4. Fourth topic:  These proposed changes to CADInterchange Profile
look to be quite important, so much so that it doesn't make sense to
recommend the existing CADInterchange Profile to authors or players.
I expect that we are likely to agree that these changes fix some
fundamental errors.  It will be good to learn from Dick what our
options are at the upcoming ISO specification review meeting in
Belgium next week.

That is a lot for one hour, but if we review points 1 & 2 quickly
we should be able to do it.

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

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