# Java Geometry package

Hi

I have developed a geometry package for Java. It contains

3D geometries, such as Boundary Representation (Meshes), NURBS (Non unified rational B-Splines) and Subdivision Surfaces. Its designed for use in games and modelling environments. The library contains several functions for the different geometries:

NURBS:

* Primitive Forms such as Circles, Spheres, Tori and many More

* Tools to create various Curves and Surfaces

* Create revolved surfaces from a NURBS-Curve

* Approximate NURBS-Curves and Surfaces from any Points

* Boolean Operations on surfaces [beta-version]

* Trim Curves on surfaces

Subdivsiosn Surfaces:

* Create Subdivsion Surface from mesh

* Various Subdivision Schemes

* A clean Framework to implement own Subdivsion Schemes

* Boolean Operations (not implemented yet)

Meshes:

* Boolean Operations on any surfaces

* Create Nurbs or subdivsions Surfaces from Meshes

* Tools to check for intersections

I also developed a small Modelling Framework and an implementation of the Framework to test the geometry library.

Is there any interest in such a geometry library? I have planned to start a project on dev.java.net if there are enough interested peoples.

-nitro

I`m interested in your library, but I don`t know where I`d find the time to contribute. Much encouragement.

:-)steve

Depending on how large (and how stable) the project is, you may want to consider starting it out in the j3d-incubator project:

https://j3d-incubator.dev.java.net/

-- Kevin

I'm very interested into your library. I don't know how I can participate (and how many time I could have for this), but I would like to say that such a library is needed !

A big part of the library is already implemented (see the description above). Except the boolean operators for Nurbs (not finished) and creating subdivsion surfaces from meshes (buggy) everything works fine.

My question is just if I should publish it or not. If I publish any contribution would be appreciated.

Nitro,

sounds good your project !!

There is very interesting project about boolean operations, by Danilo Balby at

http://www.geocities.com/danbalby/

maybe it help you in your project, in the boolean chapter ;)

Alessandro

Thanks for your link. Its basically the same approach I used for the boolean operators on meshes. But for boolean operators on NURBS that does not work because you want after the operation again a NURBS to work with and you cannot build any surface with A NURBS therefore I used the Trimcurve (so its called in maya) which uses Trimcurves to cut out parts of NURBS surface.

Ah ... and if forgot to mention that its not only usable with java3D the main part of the library just need the vecmath API. So called evaluators do transform the geometry to the requested format (Java3D, jogl, ..) until now only Java3D evaluators are implemeneted but It should be really easy to implement it for others. Basically the code from the java3d evaluators can be copied and instead of filling a geometryarray a jogl or any other api dependet geometry has to be filled up.

under http://www.gerberle.ch.vu/cs_projects.htm you can see screenshot of the boolen operators for Java3D uand the modelling framework. There is alos documentation about these to project but in german...

About the contribution I mainly thought about rewviewing the code for better design, and better documentation the javadoc is already there but probably not as verbose as it should be. There exists also some documentation in german about the boolean operators and the modelling framework, maybe some translation work would also help.

I already have requested a project at dev.java.net as jgeom. I havent yet uploaded the code because I think I need to ask my university if I can share the code and under what license. How long does it approximately take to get approved?

-nitro

Message was edited by: nitro

Just quickly glancing at the web pages, this looks like very nice work!

There are also links to two beautiful-looking reports, one titled "Boolean Operations for NURBS" and the other "Boolean Operators for Java3D". Unfortunately, both are written in (Swiss?) German, I think.

nitro - I would *love* to be able to read these. Do English translations exist? If not, is there any chance a translation could be made?

Can anyone else in the forum assist with such translation? The documents are about 35-40 pages each.

Marty

java3d-interest@javadesktop.org writes:

> Thanks for your link. Its basically the same approach I used for the boolean operators on meshes. But for boolean operators on NURBS that does not work because you want after the operation again a NURBS to work with and you cannot build any surface with A NURBS therefore I used the Trimcurve (so its called in maya). which uses Trimcurves to cut out parts of NURBS surface.

>

> under http://www.gerberle.ch.vu/cs_projects.htm you can see screenshot of the boolen operators for Java3D uand the modelling framework.

>

> -nitro

> ---

> [Message sent by forum member 'nitro' (nitro)]

>

> http://www.javadesktop.org/forums/thread.jspa?messageID=37015邗

I thought to translate them, or at least parts of it. But at the moment I haven't got any time to do this. Probably I will start with translation in December, but if anybody feels the urge to translate or start translating please feel free to do so.

I talked with the professor who supervised my thesis about Boolean Operators for NURBS. In the near future I will not be able to release my source code, because I probably get the oppurtunity to start an own research project out of this geometry package. Through this project I might get a financial resource for my planned graduate studies in North America.

Sorry.

But I surley will translate parts of the papers about Boolean Operators for NURBS and Boolean Operators for Java3D in english. I will post a link to the translation here as soon as I finished them.

-nitro

I am interested too. How do you see the contribution? Creating

notyet available geometry as e.g. a Bezier curve? Creating parts

of the documentation? Coming up with ideas? Please, let us know.

Thanks, Dirk

-----Original Message-----

From: java3d-interest@javadesktop.org

[mailto:java3d-interest@javadesktop.org]

Sent: Sunday, November 07, 2004 12:31 PM

To: interest@java3d.dev.java.net

Subject: [JAVA3D-INTEREST] Re: Java Geometry package

A big part of the library is already implemented (see the description

above). Except the boolean operators for Nurbs (not finished) and

creating subdivsion surfaces from meshes (buggy) everything works fine.

My question is just if I should publish it or not. If I publish any

contribution would be appreciated.

---

[Message sent by forum member 'nitro' (nitro)]

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