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Mr. Harry Linskens

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Posts posted by Mr. Harry Linskens

  1. Posted · Report reply

    Hi Karsten,

     

    Indeed, when I have the option of making the hull shape myself, such as for the sample files I sent, I can simply export the surface objects themselves and load the resulting IGES into NAPA without problems.

     

    However, I often have to work with geometry that has been provided by another party in a different format, such as a Parasolid. Where NAPA cannot read Parasolid files, CAESES can. Therefore, I was attempting to use CAESES to convert the Parasolid file into a format which NAPA can read, the most feasible of which was an IGES file. As Parasolid files are imported into CAESES as Brep objects, this lead to my initial question.

     

    In any case, thank you for your help, and I will contact NAPA support to see if they can do anything about their IGES interpreter. If you have any other ideas on how to handle this type of process, I am open to suggestions :).

     

    Cheers,

    Harry

  2. Posted · Report reply

    Hi Karsten,

     

    Thanks, I've included the .zip with both IGES files in it.

     

    I've taken a closer look at both files. The IGES exported from the surfaces contains 10 rational bspline surfaces (entity 128), as I would expect from the used shape. The IGES exported from the Brep, however, contains 10 loops (entity 508), 10 faces (entity 510), and a bunch of rational bspline curves (entity 126), along with the 10 bspline surfaces. I'm guessing that all these extra entities are what NAPA is having trouble with.

     

    Would it be possible to have CAESES just export the bspline surface entities from the Brep object to an IGES file?

     

    Cheers,

    Harry

    HullTestNAPA.zip

  3. Posted · Report reply

    Hi Stefan,

     

    As you suggested, I made a simple hull form in CAESES, and then exported both the surfaces and a Brep made of the surfaces as IGES files. I used the default settings for the Brep object. Looking at the two exported IGES files in Rhino V5, the shapes seem identical.

     

    When I try to import the shapes into NAPA, the IGES created from the surfaces is read without a problem. However, NAPA refuses to read the IGES created from the Brep. I am not that familiar with the specifics of the IGES format, but there must be some kind of difference in definition between the two export methods, even though they both seem to be good in Rhino.

     

    For some reason, I am not able to attach the two IGES files I made. Is there a way that I can share these files with you? I would really appreciate any help you could offer!

     

    Cheers,

    Harry

  4. Posted · Report reply

    Hi Stefan,

     

    I would like to import the IGES file into the ship stability software NAPA, which can be a bit picky with the geometry it will read.

     

    NAPA only supports a few types of IGES entities, being NURBS surfaces (entity 128), polynomial surfaces (entity 114), and trimmed surfaces (entity 144). I think that it would work best with NAPA if the shape could be exported as a trimmed surface. Could you maybe explain a little how CAESES treats a Brep object when it is exported as an IGES?

     

    Also, NAPA requires a fairly coarse tolerance in the IGES file (0.01 m) to function properly.

     

    Cheers,

    Harry

  5. Posted · Report reply

    Hi everyone,

     

    I have a hull form in CAESES as a Brep object, which I would like to export as an IGES file. However, the program I need the IGES for has a very specific set of requirements regarding the included IGES entity types and spatial tolerance settings.

     

    Is there any way that I can modify these settings for the IGES Export in CAESES?

     

    Cheers!

     

     

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