NURBS Extension to VRML: TrimmedSurface Node Problem 
Author Message
 NURBS Extension to VRML: TrimmedSurface Node Problem

Hallo Peoples

I'm trying to do some stuff with the new NURBS enhanced vrml Nodes
from Blaxxun. Problem is I cannot seem to get the TrimmedSurface Node
to work. Has anyone used the this TrimmedSurface Node? If so could you
post a sample *.wrl illustrating the use of this node.

Here is my code/script (with PROTOS omitted for brevity)

_______________________________________

#VRML V2.0 utf8

# PROTOS go Here ...

Shape {
        appearance Appearance {
                material Material {
                        diffuseColor .3 .09 .21
                        specularColor .67 .58 .83
                        ambientIntensity .0467
                        shininess .07
                }
        }
        geometry TrimmedSurface {
                t{*filter*}Contour []
                surface NurbsSurface {
                ccw     FALSE
                solid FALSE
                vDimension 4
                uDimension 4
                uOrder 4
                vOrder 4
                uKnot [0 0 0 0 1 1 1 1]
                vKnot [0 0 0 0 1 1 1 1]
                controlPoint [

                                -4 -4 0
                                -1.333333 -4 0
                                1.333333 -4 0
                                4 -4 0
                                -4 -1.333333 0
                                -1.333333 -1.333333 0
                                1.333333 -1.333333 0
                                4 -1.333333 0
                                -4 1.333333 0
                                -1.333333 1.333333 0
                                1.333333 1.333333 0
                                4 1.333333 0
                                -4 4 0
                                -1.333333 4 0
                                1.333333 4 0
                                4 4 0
                        ]
                }

        }

Quote:
}

# The End
___________________________________

As you will see the browser loads the file OK (without errors) but
nothing appears!?!

OS: WinNT/2000
Browsers: IE 6 & Netscape 6.1
Hardware: PIII, GeForce 256

P.S:
The NurbsSurface Node works fine.



Wed, 13 Oct 2004 02:11:52 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem
  Nurbs Surfaces are helpful for creating
  small models that can yield disproportiately
  detailed & natural looking images by using
  a little math to fill in some data points.

  I've done it with VRML & Java,
  both with & without VRML plug-ins,
  and have created Movie Animations with
  Java3d, VRML, JMF, and a little math.

  Nurbs, Bezier Surfaces, & Level of Detail Modeling
  ------------------------------- with VRML, Java
  http://www.*-*-*.com/ ~imaging/nurbs.html
  http://www.*-*-*.com/ ~imaging/lod_modelling.html
  http://www.*-*-*.com/ ~imaging/Bezier.java
  http://www.*-*-*.com/ ~imaging/java3d_and_vrml.html
  http://www.*-*-*.com/
http://www.*-*-*.com/ ~imaging/shout3d/models/Nurbs/tall_ship_nu...

  | Nurbs Demo & Mini-Tutorial ( VRML, Java, Shout3d )
  | --------------------------------------------------
  | The following is a NURBS model of a piston
  |  from an automobile engine made in 3D Studio MAX.
  |
  | It was the subject of a NURBS modeling tutorial,
  |  some lessons ago, and was built with a very
  | high level of detail and precision for
  | photorealisitc rendering. Of course, its original
  | polygon count was quite high, in excess of
  | 40,000 triangles. But I managed to adjust
  | the surface approximation downward in MAX
  | to create a version with under
  | 9,000 triangles. Smaller, but still a huge
  | model for realtime purposes. I converted it to
  | an Editable Mesh (polygonal) object in MAX,
  | and then used MAX's excellent export tools
  | to create a VRML file for use with Shout.
  |
  http://www.*-*-*.com/

  Nurbs Docs for Blaxxun VRML plug-in follow.
( note: Blaxxun is dancing with Chapter 11
  and we hope it will succesfully emerge
  but making money from "free" plug-ins is
  a business model with obvious problems ).

| 1.1 Basic NURBS Support
| -----------------------
| This section describes the __ proposed __
| VRML nodes and some of the basic
| characteristics of NURBS.
|
| The proposed nodes comprise a basic
| set of NURBS types that allow to
| describe arbitrary shapes. There are
| many surface construction techniques.
| To name a few:    ...
|
|
| 1.2 Trimmed NURBS
|
| ______ (  not  yet  implemented  ) _____
| _______  ~~~~~~~~~~~~~~~~~~~~~~ ________
|
|
| The t{*filter*} curve specifies a NURBS-curve
| that limits the NURBS surface in order to
| create NURBS surfaces that contain holes
| or have smooth boundaries.
|
| T{*filter*} curves are curves in the parametric
| space of the surface. An implementation approach
| can be based on the OpenGL t{*filter*} definition: ...
|
  http://www.*-*-*.com/

  http://www.*-*-*.com/
  http://www.*-*-*.com/
  http://www.*-*-*.com/

| TrimmedSurface
|
| TrimmedSurface {
|  eventIn      MFNode  addT{*filter*}Contour
|  eventIn      MFNode  removeT{*filter*}Contour
|  exposedField MFNode  t{*filter*}Contour   []
|  exposedField SFNode  surface          NULL
| }
|
| The TrimmedSurface node defines a
| NURBS surface that is trimmed by a
|  set of t{*filter*} loops (see also 1.2
| Trimmed NURBS).
|
| The surface field contains the NurbsSurface
| that shall be trimmed. The t{*filter*}Contour
| field, if specified, shall contain a set of
| Contour2D nodes.
|
  http://www.*-*-*.com/ #1.2

  Note the above refers to t{*filter*}Contour and
  further above it says TrimmedNurbs are NOT YET
  implemented, and this section is "spec/concepts"
  so I believe -- but CANNOT say definitively --
  that the VRML content you're trying to run
  doesn't run ( as you say ) because the features
  have not implemented yet.

   Moving to Java from the VRML plug-ins ( as I have )
  may be best solution for the problems of the VRML
  plug-ins including lack of portability ( to Linux
  and other Unixes -- I'm running Linux ), lack of
  features, support, extensibility, and lack of
  confidence that they will be able to support you
  in the future.

  The Sun VRML Loaders can be used to load &
  run VRML Animations with the support of PROTOs,
  TouchSensors, and animate Web3d's H-Anim Avatars,
  lies to the contrary from Justin Couch, Alan Hudson
  ( both of Yumetech ) and Aaron Walsh & Prentice Hall
  should be ignored as self-serving ( and unethical ) lies,
  and the fact that Couch & Hudson involved people
  funded by the National Science Foundation with
  Tax Payer Funds at the University of Pennsilvania
  in their illegal and unethical conduct, is dispicable.

  I'm working on relasing my simple highly portable
VRML Reading, Rendering, wRiting Applet & Application
that works on Windows-Linux-Machintosh & More
( it doesn't use Java3d ).

  You can _ see _ it here ( top left ) with female torso:

http://www.*-*-*.com/ ~imaging/sc_java3d_in_a_browser_with_vrml.jpg

  -- Paul, Java Developer & Web Animator.
  ---------------------------------------
"Imaging the Imagined: Modeling with Math & Keyboard"

[ in reply to ]:

Quote:

> Hallo Peoples

> I'm trying to do some stuff with the new NURBS enhanced VRML Nodes
> from Blaxxun. Problem is I cannot seem to get the TrimmedSurface Node
> to work. Has anyone used the this TrimmedSurface Node? If so could you
> post a sample *.wrl illustrating the use of this node.

> Here is my code/script (with PROTOS omitted for brevity)

> _______________________________________

> #VRML V2.0 utf8

> # PROTOS go Here ...

> Shape {
>    appearance Appearance {
>            material Material {
>                    diffuseColor .3 .09 .21
>                    specularColor .67 .58 .83
>                    ambientIntensity .0467
>                    shininess .07
>            }
>    }
>    geometry TrimmedSurface {
>            t{*filter*}Contour []
>            surface NurbsSurface {
>            ccw     FALSE
>            solid FALSE
>            vDimension 4
>            uDimension 4
>            uOrder 4
>            vOrder 4
>            uKnot [0 0 0 0 1 1 1 1]
>            vKnot [0 0 0 0 1 1 1 1]
>            controlPoint [

>                            -4 -4 0
>                            -1.333333 -4 0
>                            1.333333 -4 0
>                            4 -4 0
>                            -4 -1.333333 0
>                            -1.333333 -1.333333 0
>                            1.333333 -1.333333 0
>                            4 -1.333333 0
>                            -4 1.333333 0
>                            -1.333333 1.333333 0
>                            1.333333 1.333333 0
>                            4 1.333333 0
>                            -4 4 0
>                            -1.333333 4 0
>                            1.333333 4 0
>                            4 4 0
>                    ]
>            }

>    }

> }

> # The End
> ___________________________________

> As you will see the browser loads the file OK (without errors) but
> nothing appears!?!

> OS: WinNT/2000
> Browsers: IE 6 & Netscape 6.1
> Hardware: PIII, GeForce 256

> P.S:
> The NurbsSurface Node works fine.

  |
  +-[ Olumide wrote to comp.lang.vrml on 4/26/2002 ]
  |
http://www.*-*-*.com/


Sat, 16 Oct 2004 02:34:40 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem
Please confirm: are you saying that Trimmed NURBS can be implemented
with java? (with or without the Blaxxun Plugin?) Have you tried it?
Can you post a link?

Comment:
It would be nice if Blaxxun cleared the air over the implementation of
the Trimmed NURBS Node. At present, the company is sending out
conflicting messages on this topic. Take for instance the paper NURBS
in VRML (pdf) presented in Monterey by Grahn, Volk & Wolters; in
section 3 (Titled: Implementation) it reads (I'm quoting) "ALL
proposed nodes except the NurbsTextureSurface have been implemented".
The paper even has a whole subsection on its implementation of Trimmed
NURBS



Sat, 16 Oct 2004 23:50:26 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem

Hi Olumide

yes we had implemented trimmed NURBS
using Norbert Immers  Lib & glut.

However we haven't include this in the standard Contact builds, due to size
constrains.
Also in our approach with real CAD data, results are not ideal without
proper topology
or contour/tesselation matching between adjacent patches.

A) you can check out the old builds with trimmed nurbs support.

ftp://ftp.blaxxun.de/pub/developer/

ftp://ftp.blaxxun.de/pub/developer/nurbspreview/

B) the code for trimmed nurbs should be in the Web3d Contact 4.3 community
source,
so you can compile it your self.

Greetings

Holger



Quote:
> Hallo Peoples

> I'm trying to do some stuff with the new NURBS enhanced VRML Nodes
> from Blaxxun. Problem is I cannot seem to get the TrimmedSurface Node
> to work. Has anyone used the this TrimmedSurface Node? If so could you
> post a sample *.wrl illustrating the use of this node.

> Here is my code/script (with PROTOS omitted for brevity)

> _______________________________________

> #VRML V2.0 utf8

> # PROTOS go Here ...

> Shape {
> appearance Appearance {
> material Material {
> diffuseColor .3 .09 .21
> specularColor .67 .58 .83
> ambientIntensity .0467
> shininess .07
> }
> }
> geometry TrimmedSurface {
> t{*filter*}Contour []
> surface NurbsSurface {
> ccw FALSE
> solid FALSE
> vDimension 4
> uDimension 4
> uOrder 4
> vOrder 4
> uKnot [0 0 0 0 1 1 1 1]
> vKnot [0 0 0 0 1 1 1 1]
> controlPoint [

> -4 -4 0
> -1.333333 -4 0
> 1.333333 -4 0
> 4 -4 0
> -4 -1.333333 0
> -1.333333 -1.333333 0
> 1.333333 -1.333333 0
> 4 -1.333333 0
> -4 1.333333 0
> -1.333333 1.333333 0
> 1.333333 1.333333 0
> 4 1.333333 0
> -4 4 0
> -1.333333 4 0
> 1.333333 4 0
> 4 4 0
> ]
> }

> }

> }

> # The End
> ___________________________________

> As you will see the browser loads the file OK (without errors) but
> nothing appears!?!

> OS: WinNT/2000
> Browsers: IE 6 & Netscape 6.1
> Hardware: PIII, GeForce 256

> P.S:
> The NurbsSurface Node works fine.



Sun, 17 Oct 2004 04:37:25 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem

[stuff deleted]

Quote:

>   The Sun VRML Loaders can be used to load &
>   run VRML Animations with the support of PROTOs,
>   TouchSensors, and animate Web3d's H-Anim Avatars,
>   lies to the contrary from Justin Couch, Alan Hudson
>   ( both of Yumetech ) and Aaron Walsh & Prentice Hall
>   should be ignored as self-serving ( and unethical ) lies,
>   and the fact that Couch & Hudson involved people
>   funded by the National Science Foundation with
>   Tax Payer Funds at the University of Pennsilvania
>   in their illegal and unethical conduct, is dispicable.

You've been ranting and raving for a long time about the "lies" in
Aaron Walsh's book "Core Web3D" published by Prentice Hall.  I decided
to try to find the "lie" for myself in the book.  Here's what I found
on page 658.

"The Human.wrl file uses the naming convention and neutral pose
defined by the H-Anim standard.  However, it does not use the PROTOs
from that specification.  This is because of some limitations in
the VRML97 class library, which cause the joint centers to be in the
wrong
location.  Future versions of the class library may correct
this problem, but for the time being you should not assume that
the VRML97 support in Java 3D is capable of handling arbitrary
H-Anim compliant files."

Is this the "lie" and "unethical behavior" on the part of Aaron Walsh
and Prentice Hall you're refering to.  If not, where is it?  I'd
hardly say that any of it is a "lie".  The reader can judge and
experiment for themselves as you have.  Give it a rest.

Quote:

>   I'm working on relasing my simple highly portable
> VRML Reading, Rendering, wRiting Applet & Application
> that works on Windows-Linux-Machintosh & More
> ( it doesn't use Java3d ).

It's about time you contributed something useful instead of your self
serving links and relentless promotion of the Sun VRML Loaders for
which you're probably the only user in the world using that technology
from the last century.

Hoppy Thing



Mon, 18 Oct 2004 03:56:53 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem
i'm writing a tutorial about the way i export nurbs from rhino3D
http://gil.theb.free.fr/ct/nurbs/nurbs.htm

i have two problems :
i can't export weights (it seems blaxxun nurbs' weights only scale the
controlpoints coordinates)
the NurbsCurve sometime has some weird behaviour (as if it has some
wrong knot number)
http://gil.theb.free.fr/ct/nurbs/bug.wrl
http://gil.theb.free.fr/ct/nurbs/bug.wrl.txt

does anyone have some answers about that?

-GiL_TheB,



Mon, 18 Oct 2004 05:59:22 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem

sorry, can't help you....
but was wondering which version of rhino you're using.

Hope you get this figured out... it'd be very useful.

s/


Quote:
> i'm writing a tutorial about the way i export nurbs from rhino3D
> http://gil.theb.free.fr/ct/nurbs/nurbs.htm

> i have two problems :
> i can't export weights (it seems blaxxun nurbs' weights only scale the
> controlpoints coordinates)
> the NurbsCurve sometime has some weird behaviour (as if it has some
> wrong knot number)
> http://gil.theb.free.fr/ct/nurbs/bug.wrl
> http://gil.theb.free.fr/ct/nurbs/bug.wrl.txt

> does anyone have some answers about that?

> -GiL_TheB,



Mon, 18 Oct 2004 08:03:41 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem
It works with both rhino3D v1.1 and rhino3D v2.2,
well it works very well for my personnal use, but as i am writing a
tutorial and i would go futher. At this state :
-nurbssurfaces are ok
-weights are allways weird
-nurbscurves are sometimes weird
-trimmedsurfaces do work i cant see why
http://gil.theb.free.fr/ct/nurbs/trim.wrl
http://gil.theb.free.fr/ct/nurbs/trim.wrl.txt

-GiL_TheB,

Quote:

> sorry, can't help you....
> but was wondering which version of rhino you're using.

> Hope you get this figured out... it'd be very useful.

> s/



> > i'm writing a tutorial about the way i export nurbs from rhino3D
> > http://gil.theb.free.fr/ct/nurbs/nurbs.htm

> > i have two problems :
> > i can't export weights (it seems blaxxun nurbs' weights only scale the
> > controlpoints coordinates)
> > the NurbsCurve sometime has some weird behaviour (as if it has some
> > wrong knot number)
> > http://gil.theb.free.fr/ct/nurbs/bug.wrl
> > http://gil.theb.free.fr/ct/nurbs/bug.wrl.txt

> > does anyone have some answers about that?

> > -GiL_TheB,



Mon, 18 Oct 2004 16:43:33 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem
oups sory i didn't read enought close Olger's post, trimmedsufaced are
working well with contact v4.03 :D, (even if no one use it anymore
hehe).

-GiL_TheB,



Mon, 18 Oct 2004 16:57:42 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem

Quote:
> i'm writing a tutorial about the way i export nurbs from rhino3D
> http://gil.theb.free.fr/ct/nurbs/nurbs.htm
> i have two problems :
> i can't export weights (it seems blaxxun nurbs' weights only scale the
> controlpoints coordinates)

dune/white_dune also has a NurbsSurface Node (no NurbsCurve or other).

Could you please public a example wrl file and the matching screenshot from
inside rhino to identify possible problems ?

so long
MUFTI
--
Wenn Ihr CD-ROM Antrieb Brief d nicht ist, tauschen Sie ihren CDROM Antrieb
fuer d in der Fuehrung aus.
           (aus einem Softwarehandbuch, Stichworte: drive und letter)



Mon, 18 Oct 2004 18:25:56 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem
here is an example
http://gil.theb.free.fr/ct/nurbs/sphere.wrl
the red "sphere" is the geometry whithout weights
the green "sphere" is the geometry whit the weights exported from
rhino3D
the blue one is a test with the weights' invers
the pointsets are the control points

it should looks like a perfect sphere
http://gil.theb.free.fr/ct/nurbs/sphere.gif
screenshot from rhino3D

so it looks like the weights are not compute in the same way for
rhino3D/wavefront and vrml, i am not a mathematician and if someone
could give me a formula to translate those i would be great.

-GiL_TheB,

Quote:
> > i'm writing a tutorial about the way i export nurbs from rhino3D
> > http://gil.theb.free.fr/ct/nurbs/nurbs.htm

> > i have two problems :
> > i can't export weights (it seems blaxxun nurbs' weights only scale the
> > controlpoints coordinates)

> dune/white_dune also has a NurbsSurface Node (no NurbsCurve or other).

> Could you please public a example wrl file and the matching screenshot from
> inside rhino to identify possible problems ?

> so long
> MUFTI



Tue, 19 Oct 2004 07:01:22 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem
Hi,

GiL_TheB> here is an example

Quote:
> http://gil.theb.free.fr/ct/nurbs/sphere.wrl

Thanks for helping to learn this.
Using local

[ "nurbs.wrl#NurbsSurface"
]

that I think is current, in pivoron I get

#Error parsing 'controlPoint' at line 234; class of IS mapped values does not
match

??

Best Regards,
Joe


Quote:
> here is an example
> http://gil.theb.free.fr/ct/nurbs/sphere.wrl
> the red "sphere" is the geometry whithout weights
> the green "sphere" is the geometry whit the weights exported from
> rhino3D
> the blue one is a test with the weights' invers
> the pointsets are the control points

> it should looks like a perfect sphere
> http://gil.theb.free.fr/ct/nurbs/sphere.gif
> screenshot from rhino3D

> so it looks like the weights are not compute in the same way for
> rhino3D/wavefront and vrml, i am not a mathematician and if someone
> could give me a formula to translate those i would be great.

> -GiL_TheB,

> > > i'm writing a tutorial about the way i export nurbs from rhino3D
> > > http://gil.theb.free.fr/ct/nurbs/nurbs.htm

> > > i have two problems :
> > > i can't export weights (it seems blaxxun nurbs' weights only scale the
> > > controlpoints coordinates)

> > dune/white_dune also has a NurbsSurface Node (no NurbsCurve or other).

> > Could you please public a example wrl file and the matching screenshot from
> > inside rhino to identify possible problems ?

> > so long
> > MUFTI



Tue, 19 Oct 2004 11:49:05 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem

Quote:
>> the pointsets are the control points
> that I think is current, in pivoron I get
> #Error parsing 'controlPoint' at line 234; class of IS mapped values does not
> match

I think this is a unrelated problem. The world has a PointSet node
without a shapenode around it (do someone know, if this is legal ?).

BTW: In white_dune, the nodes do not look like spheres 8-(

http://www.csv.ica.uni-stuttgart.de/vrml/nurbs_sphere.jpg

so long
MUFTI
--
Gabeln nicht m?glich: zu viele Prozesse
       (deutsche Fehlermeldung von SCO OpenServer 5.0.4, Stichwort: fork)



Tue, 19 Oct 2004 18:40:22 GMT  
 NURBS Extension to VRML: TrimmedSurface Node Problem
After 4 month of painfull research, i did find the solution to export
weight from rhino3d. It was so simple LOL.
found at :  http://developer.apple.com/dev/techsupport/develop/issue25/schneider....

"There are two different conventions for representing the control
points in terms of their four-dimensional coordinates {x, y, z, w}:
Homogeneous, in which the coordinates represent the point's position
in four-dimensional space. To project it into three dimensions, the
components must all be divided through by w. Thus the point's
three-dimensional position is actually {x/w, y/w, z/w}. (Note that w/w
is always 1.)
Weighted Euclidean, in which the coordinates are already considered to
have been divided through. Thus the first three components {x, y, z}
directly represent the point's position in three-dimensional space and
the fourth (w) represents its weight."

So vrml uses homogeneous rationnal nurbs notation and rhino3d uses
euclidean rationnal nurbs notation,
the translation is very easy : (x, y, z, w) ---> (x*w, y*w, z*w, w)
example : http://gil.theb.free.fr/ct/nurbs/euclidratnurbs.wrl  (that
is what i call a sphere !!! )
complete tutorial is coming soon, sorry for my non_conventionnal
notations.

-GiL_TheB,

Joerg Scheurich aka MUFTI wrote :

Quote:
> >> the pointsets are the control points

> > that I think is current, in pivoron I get

> > #Error parsing 'controlPoint' at line 234; class of IS mapped values does not
> > match

> I think this is a unrelated problem. The world has a PointSet node
> without a shapenode around it (do someone know, if this is legal ?).

> BTW: In white_dune, the nodes do not look like spheres 8-(

> http://www.csv.ica.uni-stuttgart.de/vrml/nurbs_sphere.jpg

> so long
> MUFTI



Thu, 28 Oct 2004 15:37:56 GMT  
 
 [ 14 post ] 

 Relevant Pages 

1. VRML browser for NURBS

2. Blaxxun VRML NURBS plug-in also in R3???

3. NURBs in VRML?

4. vrml+nurbs again

5. cool NURBS modeling program that can export VRML 2.0 -- free beta --

6. vrml+nurbs

7. VRML 2.0 and NURBS

8. NURBs in VRML and AFX

9. vrml nurbs examples for anything but blaxxun

10. Problems with Separator nodes in VRML-file

11. Security problem in a VRML JAVA Script node?

12. Java &,VRML scripting node problems.

 

 
Powered by phpBB® Forum Software