Hello, as far as I know Blender has a NURBS-library based on NURBS++ (or Nurbana?), maybe It is possible to start from there, just thinking aloud... -------- Original-Nachricht --------

Datum: Sun, 8 Feb 2009 11:23:15 +0000 Von: Peter Barker An: boost-users@lists.boost.org Betreff: Re: [Boost-users] NURBS curves/surfaces

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We have the same interest and need for boost. What applications do you plan to use NURBS?

B/Rgds Max

Hi Max,

I currently work for a CAD company in the footwear industry and our curves/surfaces are implemented using splines from code home-grown in the 70s. Manning and/or Ferguson I believe they're called. This is making interchange between other CAD applications difficult. If our company used NURBS internally it would help.

There is a project called Nurbs++ (http://sourceforge.net/projects/libnurbs/) but it's not seen any activity for almost 7 years. I've looked at the code and it's not the best. Header files including .cpp files and other strange stuff. Trying to get it compiled and link with it means rewriting a lot of the code.

There is a commercially available library called NLib available from Solid Modeling Solutions (http://www.smlib.com/nlib.html). It's quite pricey to buy.

The NURBS Book (http://www.amazon.co.uk/Nurbs-Book-Monographs-Visual-Communication/dp/3540615458/ref=sr_1_1?ie=UTF8&s=books&qid=1234091419&sr=8-1) contains a lot of maths and pseudocode for NURBS algorithms. These algorithms are what NLib is based upon, but the latest NLib has more functionality I understand. The authors of this book are the original authors of NLib before Solid Modeling Solutions bought the rights to the library.

Currently the book is far beyond me mathematically! I'm making a real effort to learn maths so implementing the algorithms from the book might be a good exercise. Then again it might be something I will never finish.

Have you done much research on what's available? Would be interested in hearing what paths you're looking at taking.

Regards,

Pete _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Pete, You might also look into OpenCascade (www.opencascade.org). It is *huge* and lacks comprehensive documentation, but if you have an editor with symbol and header file lookups, and are willing to code dive, then OpenCascade can help avoid lots of the headaches you'd encounter implementing your own NURBS kernel. This is especially true if you are trying to exchange data with other CAD systems, as OpenCascade has direct support for reading/writing IGES and STEP, and can convert (most?) non-NURBS surfaces into NURBS form. I have been able to use OpenCascade to exchange IGES and STEP AP203 data with Rhinoceros 3D successfully, including data that contain non-NURBS geometry. By the way, the comments are predominantly in French, so if you know the language (I don't), you'd be ahead of the game. :-) Cheers, Demian

What I know is that it is using some of the geom stuff provided by CGAL.

May be this link contains some useful info too: http://www.risc.uni-linz.ac.at/projects/basic/cgal/nurbs_in_cgal/ ********************************************************************** This communication contains information which is confidential and may also be legally privileged. It is for the exclusive use of the intended recipient(s). If you are not the intended recipient(s), disclosure, copying, distribution, or other use of, or action taken or omitted to be taken in reliance upon, this communication or the information in it is prohibited and maybe unlawful. If you have received this communication in error please notify the sender by return email, delete it from your system and destroy any copies. **********************************************************************

I've got lots of options to consider now. Thanks to everyone for replying. If I manage to get time to pick one and use it, I'll let you know how I get on Max. Regards, Pete

Hello Pete What's in my mind now is quite similar with yours you've mentioned. :-)

Hi Max,

I currently work for a CAD company in the footwear industry and our curves/surfaces are implemented using splines from code home-grown in the 70s. Manning and/or Ferguson I believe they're called. This is making interchange between other CAD applications difficult. If our company used NURBS internally it would help.

Thanks for your reply and information. I hope we could keep touch at this area for this similar interest and needs.

There is a project called Nurbs++ (http://sourceforge.net/projects/libnurbs/) but it's not seen any activity for almost 7 years. I've looked at the code and it's not the best. Header files including .cpp files and other strange stuff. Trying to get it compiled and link with it means rewriting a lot of the code.

I ever had a closer look at it, too. But as you've said, It's quite old and odd, and lack of real fuctionalities. Obviously it is not a qualified candidate. :-)

There is a commercially available library called NLib available from Solid Modeling Solutions (http://www.smlib.com/nlib.html). It's quite pricey to buy.

Yes, I've heard of this and tried to get a copy for research, but failed.

The NURBS Book (http://www.amazon.co.uk/Nurbs-Book-Monographs-Visual- Communication/dp/3540615458/ref=sr_1_1?ie=UTF8&s=books&qid=12340914 19&sr=8-1) contains a lot of maths and pseudocode for NURBS algorithms. These algorithms are what NLib is based upon, but the latest NLib has more functionality I understand. The authors of this book are the original authors of NLib before Solid Modeling Solutions bought the rights to the library.

I've skimmed through this book some time before, and found it's fairly good. But the same prolem is that it's also a little bit aged without update.

Currently the book is far beyond me mathematically! I'm making a real effort to learn maths so implementing the algorithms from the book might be a good exercise. Then again it might be something I will never finish.

:-) Yes, it has lot of math stuff, even though not so hard. most are algorithmatic.

Have you done much research on what's available? Would be interested in hearing what paths you're looking at taking.

I have wide range of CAD applications of geom stuff, esp. NURBS. But all of them are not of commercial nature - just leisure research and experiment. Then I have never focused on this topic for a long time, just keeping an eye on the available resources, on web especially. Another stuff I think may worth a closer look is OpenCASCADE. It seems to contain some NURBS functionally. One difficulty is that this package is TOO TOO large in size. That means you need much more time to get familiar with it. You can easily get the link for downloading it by Google. The latest version ,open source, is 6.3.0.

Regards,

Pete

B/Rgds Max