Subdivision NURBS question

Discussion
2011-11-17
2013-04-05
  • Juan Carlos
    Juan Carlos
    2011-11-17

    I read in features that Ayam support Subdivision NURBS:

    Subdivision NURBS

        First modelling environment to support Subdivision NURBS.
        Conversion operations from NURBS surfaces and polygonal meshes.
        Modelling operations: Face Extrude, Face Merge, Patch Merge, Knot Manipulation.
        PLY import/export.

    But I would like to know if, for example, I could import a OBJ with a mesh of quadfaces (a typical mesh to do subsurf with a good topology), convert it to nurb surfaces and save it as 3dm. If it is possible I don't find where.

    Thanks :)

     
  • Greetings,

    no, Subdivision NURBS is about going the exact opposite
    direction, from NURBS to Subdivision.

    If your mesh has certain regular connectivity, i.e. can be
    unrolled to a "rectangular grid", you could craft some
    script that does what you expect, but I suppose your
    data has irregular connectivity anyway.

    regards,
    Randolf

     
  • Juan Carlos
    Juan Carlos
    2012-03-29

    Thanks a lot for your answer. Usually my meshes, due to are created for a good subdivision behavior, could be unrolled that way I think. So I will think on that if someday have a little free time for experiments.

    There is plans for subdivision -> NURBS implementation?

    I don't know if I should open a new topic, but at this time I never succeded open a 3dm rhino file in Ayam (even with 1.20),  it's normal due to aren't all features implemented to do that with complex objects or for another reason?

     
  • Greetings,

    if Ayam fails to load 3dm Rhino files, they are probably written for/with
    version 4 of the OpenNURBS library. Ayam only supports version 3 at
    the moment. You should be able to load the file into Rhino and save
    for older versions though… That should work.

    There are no plans to implement Subdivision->NURBS.
    Plans for the next version (1.21) will be published
    soon on the project homepage.

    kind regards,
    Randolf

     
  • Juan Carlos
    Juan Carlos
    2012-03-31

    Thanks for the info. I saved my heavy rhino file for tests in rhino 3 version and it started to import, unfortunately Ayam crashed in the middle of the process but at least I know thanks to you that all rhino files must be saved on that version.

    I will check that plans as soon are available. Ah, in case you didn't know (surely you know it) OpenNURBS 5.0 was released recently!

    Best regards,
    Juan Carlos

     
  • Greetings,

    as I can import example files for V1-V3 from the OpenNURBS distribution
    fine, there must be something with your file. Can you trim it down to the
    pieces which fail to import and send it my way (via email)?

    kind regards,
    Randolf

     
  • Juan Carlos
    Juan Carlos
    2012-04-08

    Hi,

    Its a very complex model, so I don't think I have time until summer, but them, I hope to could do more test and send you the conflictive part.

    Best regards,
    Juan Carlos