[X3D-Public] Examples for X3D Nurbs Component

Don Brutzman brutzman at nps.edu
Mon Feb 13 07:17:31 PST 2012

On 2/13/2012 5:30 AM, Vincent Marchetti wrote:
> On Feb 12, 2012, at 12:38 PM, Don Brutzman wrote:
>> Can we copy CAD and X3D public mailing lists on this?
> Yes, certainly.

thanks, done

>> Please advise what tool(s) you used to create these examples so that we can update
>> the meta-tag references
> I made these files with software I have developed in Python using Numpy and SciPy libraries
> How about
> <meta content='Python language scripts using Numpy, SciPy libraries' name='generator'/>

Great, interesting.  I also included the following url:  http://numpy.scipy.org

> Also, I had seen the license terms at http://www.web3d.org/x3d/content/examples/Basic/license.html and those are agreeable to me for publishing the examples.

Excellent.  Again thanks for the contribution.

>> ===================================================================
>> The third scene appears to have problems: TrimmedNurbsWithHole.x3d
>> - BS Contact reports:
>> X3D syntax error: in C:\www.web3d.org\x3d\content\examples\Basic\NURBS\TrimmedNurbsWithHole.x3d:
>> Unknown node class 'NurbsTrimmedSurface'
>> X3D syntax error: in C:\www.web3d.org\x3d\content\examples\Basic\NURBS\TrimmedNurbsWithHole.x3d:
>> Could not understand child element 'NurbsTrimmedSurface' of 'Shape'
> I think this is because BSContact has not implemented the NurbsTrimmedSurface node

sounds likely, issue report submitted to

>> - InstantReality reports:
>> WARNINGAvalonNurbsTrimmedSurface/104173728 has ambiguous fields (2) adding Contour2D/528465216
>> WARNINGAvalonRemap bestMatch Field in addChild(): 2/0
>> WARNINGAvalonNurbsTrimmedSurface/104173728 has ambiguous fields (2) adding Contour2D/528468768
>> WARNINGAvalonRemap bestMatch Field in addChild(): 2/0
> These messages look like they arise from removing the containerField attributes from some nodes. The NurbsTrimmedSurface node
> contains child-elements for two separate X3D fields:
> -- a single Coordinate node for the controlPoint field of type SFNode
> -- multiple Contour2D nodes for the trimmingContour field of type MFNode

hmmm.  these look like they match the default containerField values, which is why
they aren't in the file.  I pushed them back in.

Made some changes to X3D Schema and X3D-Edit, will run a new release today.

>> WARNINGOpenSGCan't create geometry with glu version Microsoft Corporation. Version 1.3 and above is needed!
>> ===================================================================
> I think this is because Microsoft is not keeping up with the latest OpenGL library version in the implementations in the Windows system libraries. I get this same message on my Windows install of Instant Player, but not on my Mac OS X install. However, (see below), both the Windows and Mac Instant Player browsers can display a NurbsTrimmedSurface node.

Just the notion of depending on Microsoft to keep up with OpenGL
doesn't sound very likely to happen.

I checked the NVIDIA Quaddro 4000M driver for my laptop, it says
that it is up to date.

Hopefully the InstantReality folks will look at this scene.  Let's
post to their forum.  http://forum.instantreality.org/

... now posted at

I will post these update examples later today.  Modifications already
checked into subversion.

> The TrimmedNurbsWithHole.x3d example, in any case, will not render correctly in InstantPlayer because of the disagreement (or ambiguity, or discrepancy) in how NURBS internal coordinates are to be placed. The screenshot I supplied in TrimmedNurbsWithHole.jpg was made with the Octaga browser. I am attaching an X3D file (trimmed_nurbs_with_hole_transposed.x3d) which has had the X3D field values rearranged and transposed so as to render the same shape as the TrimmedNurbsWithHole, in the Instant Player browser. It renders in both Windows and Mac versions.
> I have no objection to publishing the transposed version somewhere on the Web3D site. I think it would be confusing to place it in the examples section if we would have two contradicting files ostensibly rendering the same shape. It's my judgement that the current TrimmedNurbsWithHole.x3d example represents a correct implementation of the X3D standard for a NurbsTrimmedSurface node.
> Vince Marchetti

Vince, how about we do both?  We could put both versions side by side
in one scene to clearly illustrate this issue.

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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