OPEN CAD FORMAT

Developers
martin
2007-09-16
2013-04-22
  • martin
    martin
    2007-09-16

    Hi all:

    We are working in a new cad format here:
    http://groups.google.com/group/open_cad_format

    There many interesting people inside. It´s important for us the opinion of BRL-CAD.

    The last disccusion was by Franz Reiter from gcad3d and BRL-CAD.

    It would be a BRL-CAd opinion here:
    http://groups.google.com/group/open_cad_format/web

    Regards.

     
    • Sean Morrison
      Sean Morrison
      2007-09-17

      Martin,

      Thanks for the message and note.  I'd seen the message about the new group starting up on the linux-cad mailing list as well.  There's lots of interesting commentary started there though what still doesn't seem clear is what problem is actually being solved.  "CAD" means very different things to different people.  There is also CAD for various purposes and domains that have lots of overlap, but some are exclusive.  The Industry Diagram that I put together for describing where BRL-CAD is presently situated (available at http://ftp.brlcad.org/Industry_Diagram.png\) gives you an idea of some of the domain complexities involved.  If you're scope is going to be comprehensive, then that is really one monumental task even just for a representation format.

      IGES tried to answer that question in the 80's and 90's (and didn't do too great).  The major CAD vendors then got together again in the 90's and came up with the beast that is known as STEP.  STEP did much better and defining a format that can represent just about anything, but with that came a wealth of complexity.  Also, being an expensive and massive ISO standard hasn't really helped its adoption outside of commercial industry.

      We already have IGES support in BRL-CAD and are now in the process of implementing a full STEP processing library over the next year.  We do have some progress already made in this regard, having reviewed/updated NIST's STEP parser in the past.  We also already have the relevant portions of the STEP ISO 10303 APs that pertain to CAD and solid modeling.  If the folks involved in the open_cad_format efforts are interested in collaborating with that effort, I'm sure the STEP APs could probably be made available to people participating in the effort.

      In a similar vein, working on a new geometric processing layer for BRL-CAD is also something we're going to likely continue to work on for the upcoming year given our expansion goals of becoming more of a hybrid modeling system.  I'll keep an eye on the open_cad_format group and encourage others to keep an eye towards what we're doing as well to see if we can find something mutually beneficial for everyone.

      Cheers!
      Sean